DATA EVALUATION AND METHODS RESEARCH

Methodologic Problemsin Children’s Spirometry

TechnicaI problems encountered in the analysis of spirometry datacoHected on chiIdren aged 6-11 years in the United States, 1963-65,and the solutions are detailed in a narrative account. Data fromother methodologic studies are presented and discussed. Behavioraland technical problems in the survey measurement of pulmonaryfunction in children are discussed.

DHEW Publication (PHS) 78-1346

Series 2Number 72

U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFAREPublic Health Service

National Center for Health StatisticsHyattsville, Md. November 1977

Libraty of Congress Cataloging in Publication Data

Palmer, Alan.Methodologic problems in children’s spirometry.

(Vital and health statistics: Series 2, Data evaluation and methods research; no. 72)(DHEW publication; no. (PHS) 78-1346)

Includes bibliographical references.1. Spirometry. 2. Pediatric respiratory diseases–Diagnosis. 1. Hamill, Peter V. V., joint

author. II. Drizd, Terence, joint author. HI. Title. IV. Series: United States. NationalCenter for Health Statistics. Vital and health statistics: Series 2, Data evaluation andmethods research; no. 72. V. Series: United States. Dept. of Health, Education, and Wel-fare. DHEW publication; no. (PHS) 78-1346.RA409.U45 no. 72 [RJ433.5.S6] 312’.07’23s 77-22566ISBN 0-8406-0098-04 [618.9’22’40754]

For sale by tbe Snperintandent of Doenments, U.S. Government MIItlm o~~Washington, D.C. !2tM@2

Wok No. 0174224602-2

NAT ONAL CENTER FOR HEALTH STATIST CS

DOROTHY P. RICE, Director

ROBERT A. ISRAEL, Deputy Director

JACOB J. FELDMAN, Ph.D., Associate Director for Analysis

GAIL F. FISHER, Associate Director for the Cooperative Health Statistics System

ELIJAH L. WHITE, Associate Director for Dtzta Systems

JAMES T. BAIRD, Ph.D., Associate Director for International Statistics

ROBERT C. HUBER, Associate Director for Management

MONROE G. SIRK.EN, Ph.D., Associate Director for Matherwtical Statistics

PETER L. HURLEY, Associate Director for Operations

JAMES M. ROBEY, Ph.D., Associate Director for Program Devebpment

PAUL E. LEAVERTON, Ph.D., Associate Director for Research

ALICE HAYWOOD, Information Officer

DIVISION OF HEALTH EXAMINATION STATISTICS

MICHAEL A. W. Hattwick, M.D., Director

PETER V. V. HAMILL, M. D., M. P.H., Medical Adviser

JEAN ROBERTS, Chiej Medical Statistics Branch

ROBERT S. MURPHY, Chiej Survey l?kming and Development Branch

COOPERATION OF THE US. BUREAU OF THE CENSUS

Under the legislation establishing the National Health Survey, the Pubfic Health Service isauthorized to use, insofar as possible, the services or facilities of other Federrd, State, ar privateagencies.

In accordance with specifications established by tbc Nationrd Center for Health Statistics, theBureau of the Census, under a contractual agreement, participated in planning the survey andcollecting the data.

Vital and Health Statistics-Series 2-No. 72

DHEW Publication (PHS) 78-1346Library of Congress Catalog Card Number 77-22566

CONTENTS

Introduction ............................................................................................................................................

Background .............................................................................................................................................

Physiology of Airflow .............................................................................................................................

Sources of Signal Variances .....................................................................................................................

Methodology ...........................................................................................................................................

Initial Limitations of Dat&......................................................................................................................

Criteria Development ..............................................................................................................................

Remeasurement Procedure ......................................................................................................................

Classification of Spirogram......................................................................................................................Class I ................................................................................................................................................Class II .............................................................................................................................................. .

Discarded Data ...................................................................................................................................... ..Class 111.................................................................................................................................... ..........class Iv ..............................................................................................................................................

Verification and Validation of the Data Classification System ................................................................

Criteria for Merging the Data Clmscs .......................................................................................................

Strengths of the Data ............................................................................................... ...............................

Comparison With Other Data ..................................................................................................................

Analytic Problems ...................................................................................................................................

Interaction of Volume and Flow .............................................................................................................

Substudics .......................................................................................................................................... .....Miscellaneous Substudies ...................................................................................................................Salt Lake City Substudy ....................................................................................................................Annapolis Substudy ......... .................................................................................................................

References ...............................................................................................................................................

1.

2*

3.

LIST OF FIGURES

Schematic drawing of a wet system spirometer ..................................................................................

Normal time-volume spirogram showing the three component ph~es ................................................

Forced expiatory spirogram illustrating measurements of FVC, FEV 1.Cl,and FEF25.75% md. . .

identification of zero tme ...............................................................................................................

I

1

3

3

4

5

6

6

777

888

8

8

9

10

11

13

14141721

23

2

2

2

...Ill

4. Maximum expiatory flow-volume mme ............................................................................................ ~

5. Effect of TLC and RV attenuations of FES on FEF25-75~0 me=ure of flow rate ............................. 13

6. FES curves: acceptable decay curves and curves prematurely terminated .......................................... 15

LIST OF TEXT TABLES

A. Frequency distribution of standing height, by age, sex, and sex and age: Salt Lake City, 1974 ......... 17

B. Frequency distribution of FVCT (best of five trials), by age and sex: Salt Lake City, 1974 .............. 19

C. Frequency dktribution of FVCT (better of first two tri~s): Sdt Lake City, 1974 ............................ 20

SYMBOLS

Data not available-----—---—-----—-------- ---

Category not applicable— ----------------------- . . .

Quantity zero-------— ------------------------ -

Quantity more than Obut less than 0.05---- 0.0

Figure does not meet standards ofreliability or precision-—-—---—---—-- *

METHODOLOGIC PROBLEMS IN CHILDREN’S SPIROMETRY

Alan Palmer, Ph.D., Center for Occupational Environmental Safety and Health,Stanford Research Institute, Peter V. V. HamiIl, M.D., M.P.H., and

Terence A. Drizd, M.S.P.H., Divzkion of Health Examination Statistics

INTRODUCTION

This report is a companion piece to Series11, No. 1641 and most profitably the readershould, at least, read the introduction and skimthat report before reading this one. This reportcould be considered as playing the subordinaterole of a series of very long technical footnotesto that report. The justification of two separatepublications (in two different NCHS reportseries) is an attempt to maintain narrative flowof the primary report, to better handle unwieldylength, and to appeal to different sets ofspecialized readers.

However, these are not the only considera-tions. This report presents spirometry resultson 6- and 7-year-olds from two small studieswhich have not been presented before; and thisrep ort, although presenting data and detailedarguments that support the Series 11 report,can be considered to have a narrative flow ofits own.

While the primary function of the firstreport was to present and discuss data collectedin HES Cycle II (and, subsidiarily, to take intoconsideration the methodologic complexitiesand limitations), this report, although presentingsome new data, details the methodologicproblems encountered in the collection andanalysis of the HES Cycle II spirometry data,provides a narrative account of how some ofthem were solved, and touches on most of theproblems and limitations involved in spirometrytesting in children, especially in a survey setting.

This report does not simply expand thetechnical details of the companion Series 11

report. It has a different emphasis and providesthe basis for the many refinements in spirometrydata collection, data processing, and dataanalysis made in subsequent HES cycles ofexaminations that will appear in forthcomingspirometry reports on children and on adults.

BACKGROUND

The father of modern spirometry was JohnHutchinson, an English physiologist, who wasthe first to name the subdivisions of lung vol-ume and describe methods for measuring them.zIn 1846 Hutchinson devised the first spirom-eter, an instrument to measure static Iung vol-ume. This closed circuit volume measuring de-vice consisted of a cylindrical bell immersed ina reservoir of water into which air forcefullyexpired from the lungs could be blown by meansof a connecting breathing hose. Using thisinstrument he was able to diagnose or excludevarious forms of pulmonary disease. Only inrecent years has this testing technique beendeveIoped to include measurements of the rateor airflow, which now form the basis of themost widely used test of lung function, theforced expiatory spirogram (FES). This advancewas made by Tiffeneau and Pinelli, whoconnected a rotating kymograph to the spirom-eter (figure 1), permitting assessment of thedynamic, as well as the static, characteristics ofthe h_mg.3 The kymograph, rotating at , aconstant speed, permits the display of atime-volume coordinate recorded by a penattached to the spirometer beIL

1

Mo.llwece

Record, ng pen

Kymograph

Figure 1. Schematic drawing of a wet system spirometer

The test instruction calls for a maximalinhalation, placing the cardboard mouthpiece(fastened to the air tube of the spirometer) intothe mouth, carefully sealing the lips to preventair leakage and then forcefully expiring asrapidly and as completely as possible. During themaneuver the attending technician verballyexhorts the standing subject to blow as hard aspossible until no more air can be expired. Acorrectly executed maneuver provides a mono-tonically increasing volume curve which ultimate-ly presents a plateau, and is free from inhalationartefacts (figure 2). From this wave form,calculations are made of numerous time and

Phax IEffort dependent

6/

Phase I I Phase I I ICritical flow Terminal leakage flow

TIME IN SECONDS

Figure 2. Normal time-volume spirogram showing the three

volume increments from which volume andflow-rate measurements are derived.

The three most common measurementsobtained from the FES and used in theassessment of pulmonary function are: (1) theforced vital capacity (FVC), defined as themaximal volume of air that can be forcefullyexpelled from the lungs from a maximalinhalation; (2) the forced expiatory volumeduring the first second (FEV1 ..); and (3) theforced expiatory flow rate (FEF) between 25percent and 75 percent of the forced vital capa-city (FEFZ5.T5%). (See fi~re 3.)

Measurement of the FVC can revealmechanical defects of the chest cage thatprevent the full expansion of the lungs, i.e.,chest wall deformity, loss of lung tissue, or Iossof lung elasticity as in restrictive lung diseases.The flow-rate measurements, FEV1.O and

FEF25 -7594,provide an objective method ofquantitating obstructive lung diseases, since intheir presence these flow rates are impaired.

Volumes are calctdated by multiplying thenumber of millimeters of bell movement asrecorded on the kymograph by a bell calibrationfactor. This gives a volume correct to ambienttemperature and pressure saturated with watervapor (ATPS). Because expired air is collected ina spirometer at room temperature (usually25° C), gas expired from the lungs (at body tem-perature, 37° C) cools and subsequently con-tracts. This underestimate of gas volume is cor-

/

—FEF25.7E%

FV c

T

~25% FVC

Zero.time adiusted/1.secoml p.im

Baseline

o 1 2 3 4

TIME IN SECONDS I

Figure 3. Forced expi ratory spirogram illustrating measurementsof FVC, FEV1 .. . and FEF25.75% and identification ofzero timecomponent phases

rectable to body temperature andpressuresatu-rated with water vapor (BTPS) by multiplyingthe ATPS measurement value by the BTPS cor-rection factor obtained from a reference chart orcalculated using the following equation:

Volume (BTPS) =273 + 37° C (body temp.)273 + 25° C (spirogram temp.)

~ 750 mm Hg (BP) -24 mm Hg (pH 20 at 25”C)

750 mm Hg -47 mm Hg (pH 20 at 37°C)

PHYSIOLOGY OF AIRFLOW

Dayman has shown @at during the perform-ance of the FES, airflow can be divided intothree components:4 Phase I is effort-dependentflow culminating in the peak fIow, the maximalflow velocity, for that breath. This is foIlowedby a phase of constant deceleration of volumeexhaled (phase II). A third phase is terminalleakage flow (figure 2). A conrectly executedspirogram, therefore, demands that phase I beginat the total lung capacity (TLC), and end at theresidual volume (RV) in phase III. Phase I is ameasure of how fast the subject initiated theexpiatory effort and is called “effort depend-ent” because it directly reflects the subject’sunderstanding of the test instruction and hiswillingness and ability to cooperate. The dy-namics of airflow are best demonstrated whenthe flow rate and the volume signals are dis-played as a single graph (figure 4). Examinationof a flow-volume spirographic loop illustrateshow the volume signal abruptly leaves the vol-ume baseline and rapidly culminates in peakjl!ow and then shifts into phase II, the beginningof critical flow. This phase is believed to be mostindependent of effort variation, implying thatboth the constant of deceleration and the flowsare regulated by airway size and not by the sub-ject’s effort. It is this phase of the spirogramthat imparts diagnostic character and reproduci-bility. The point at which critical flow emergesis approximately 25 percent after the initiationof the FES while phase III occurs at approxi-mately 75 percent of the FES and representsasynchronous emptying of various portions ofthe lung due to air trapping. Here flow rate isreduced and the volume of air expired is mini-

Phase I Phass 1I Phase III!

8-2~%= 6-

*mK-

:i4-~

~

m~2-Cj

u.

0 1 2 3 4 5 6

VOLUME IN LITERS

Figure 4. Maximum expiatory flow-volume curve

maI and it is at this point in the test that thesubject strains to exhale the last of his air andhis face becomes red due to effort. A correctlyexecuted spirogram must include phase III, sinceit is the portion of the curve that insures repro-ducibility of the FVC and all of those flow-ratemeasurements which are expressed as a propor-tion of the FVC. (Phase III is also of currentinterest for the early detection of obstructivelung disease.)

SOURCES OF SIGNAL VARIANCES

Three important factors contribute to thevariability of the test maneuver: equipmentaccuracy, subject cooperation, and technicianexpertise. The spirometer should be accurate,linear, and have a frequency response of at least8-10 Hz to permit capture of the highest fre-quency components present in the FES. Carefulattention to the calibration of the kymographspeed and volume response of the instrumentwill permit accurate and reproducible data to berecorded. Subject cooperation depends on indi-vidual motivation and complete understandingof the test instructions. Contrarily, maximaIeffort may also be withheld in circumstanceswhere this maneuver precipitates pain or cough-ing spasms or if the subject is a candidate fordisability status and stands to gain financially byproducing a positive test.

An astute technician can usually identifythese problem areas and act appropriately either

3

to correct a subsequent FES trial or to discardthe data. Such a technician takes on the multipleroles of monitor, bully, cheerleader, and psy-chologist as he strives to elicit a maximal. re-sponse from the subject. The end result of theseskills is a strong interaction between technicianand examinee which results in the collection ofdata that represents the best possible estimate ofthe physiologic capability of the lungs. Experi-enced technicians frequently vary in their per-formance. Day-to-day testing can be extremelyboring and test subjects can be frustratingly un-cooperative; therefore, the stamina to maintainthe same level of expertise during a lengthy test-ing operation is variable.5 *6

A correctly performed spirogram trial shouldembody the three phases described, even in thepresence of disease. Those with an obstructivedefect will have a reduced velocity in phases IIand III, but can often achieve a normal vitalcapacity by greatly lengthening the duration ofexpiration. Conversely, in the presence of re-strictive lung disease, flow rates can be normaland the vital capacity reduced. Testing withoutadequate quality control can result in spuriousmeasurements. For example, should a subjectwith an obstructive lung defect prematurely ter-minate his expiatory effort before the emer-gence of phase III of the spirogram, theFEF2 ~.7s % measurement will be artificially ele-vated since it will now fall between phases I andII of the spirogram, a steeper portion of the sig-nal, as opposed to between phases II and III(figure 2). Likewise, the ratio FEV1 .o/FVC willbe artificially increased. Another serious proce-dural error occurs when a subject trumpets intothe mouthpiece (pursing the lips in front of themouthpiece as opposed to fully inserting thetube into the mouth). The incomplete lip sealcan result in a Venturi defect in which air fromthe outside is drawn into the spirometer alongwith the expired air, resulting in spuriously largevital capacities. Such errors can be reduced byinstituting a series of quality control checksupon the data; those used by this survey will bediskussed in the section “Methodology” that fol-lows.

A fundamental error is committed in spiro-metric evaluation when a composite spirogram isused in diagnosis, especially when inadequate

quality control standards are operative. Thisoccurs when, from a series of trials, the largestFVC is taken from one trial and the largestFE F2s.7 G% is taken from another of the trials.As already discussed, a subject with an obstruc-tive lung disease could achieve a normal vitalcapacity but with low flow rates because of theobstructive defect. Then on a subsequent trial hecould perform a maximal effort that encom-passes phases I and II of the spirogram but pre-maturely ends prior to the emergence of phaseIII, therefore, artificially elevating the flow rate.Conceivably, by use of a composite trial, theFVC and FEF25.7 ~% could both be in a normalrange when in fact moderate to severe obstruc-tive lung disease is present, and so could result ina false negative test.

METHODOLOGY

The child entering the spirometry room wasmet by a trained technician who described anddemonstrated the breathing maneuver.

The test instruction required that the subjectinhale to maximal inspiratory capacity throughthe spirometer hose, then blast the air out asforcefully and rapidly as possible into themouthpiece, sustaining the effort until no moreair could be expelled. During the expiatoryeffort, the attending technician verbally ex-horted the subject. During the test procedurethe child was standing, and a nose clip was usedto prevent air from escaping through the sub-ject’s nose.

Although the test procedure called for sev-eral practice attempts prior to executing thetest, usually (because of the lack of time) onlyone practice trial was given; then at least twotrials were recorded. Because of the physics ofairflow when a maximal expiatory effort isachieved, it can be expected that the personalmorphology of each subject’s volume signal willbe reproducible within the limits of biologic var-iation. Although no systematized procedureswere devised in Cycle II to quantitate the degreeof variability between trials during the test pro-cedure, the attending technician visually moni-tored the spirographlc wave forms to determineif the tracings were reasonably reproducible. Re-

gardless of whether or not reliable data weredemonstrated owing to a limitation of time thetest was discontinued after two or three trials.

The forced expiatory spirogram was meas-ured on a Collins 6-liter Vitalometer, a water-sealed, counterbalanced system. Volume dis-placements were recorded on a moving chart(kymograph) by a writing device connected tothe bell by a pulley system (figure 1). Thekymograph was driven by a motor at a constantspeed (32 mm/s).

Prior to each day’s testing, the barometricpressure and temperature were noted and re-corded. During the day the temperature was re-checked periodically and recorded wheneverchange occurred. The water level in the spirom-eter was carefully maintained within 11%inchesof the top of the bell canister to prevent exces-sive spirometer dead space, which could cause anunderreading of the recorded signal.

INITIAL LIMITATIONS OF DATA

Of the 7,119 subjects examined, no spiro-graphic data were obtained for 187 exarninees.Reasons for this data loss ranged from lack ofthe subject’s physical coordination and/or his in-ability to follow any verbal directions, to thepresence of pathoIogy that precIuded valid datacollection. The spirographic tracings obtained onthe other 6,932 subjects were initially measuredby technically inexperienced clerks, wherebymeasurements of the FVC, FEV1.0, and theFEF25 -75% parameters were made on the trialjudged to represent the best spirometer effort.Ideally, both the best and second-best trialshould have been measured to permit betterassessment of data reliabilityy; however, thiscould not be done because of the large amountof additional time and money involved. In addi-tion, the maximum number of recorded trialsper subject was, in most cases, two–occasionallythree.

As a preliminary to analyzing the data, a re-assessment of their overaII quality and potentialvalue was made by Palmer and Harnill. All of thespirometric tracings were reexamined and com-pared with the measurements origirdy per-formed by the unskilled clerks to determine the

overall technical quality of the data (i.e., spiro-grams, morphology, and the recorded measure-ments). The quality of the spirograms rangedfrom good to technically unsatisfactory and themeasurements, as recorded, were frequently un-acceptable. The two most frequent measurementerrors were the wrong choice of “the best trial”(on which all measurements are based) and theincorrect determination of zero time point. Inaddition, many of the actual measurements wereunderestimated and several hundred sets ofspirograms, although measured, were obviouslyunacceptable because of technical errors in theoriginal performance of the FES. Because ofthese problems, the decision was made to aban-don the analysis.

However, one year later the decision toabandon Cycle H data was reversed because aIarge part of the HES Cycle III (youths 12-17years old) spirometry recordings were lost. TheCycle III data were of much better technical qual-ity: the testing situation was improved, moresophisticated electronic equipment was used,and the technicians were well instructed, super-vised, and monitored. Most of the limitationsjust mentioned in Cycle II data on the youngerchildren had been successfully corrected. Inaddition, the FES was recorded on magnetictape which would have enabled greater scopeand ease of data processing, minimized measure-ment and recording error, and allowed muchgreater range and flexibility of analysis.

However, when seven cartons containingmost of these tapes were being moved from onelocation to another for “safekeeping,” they werecarelessly left on the building’s loading platformand were carted off to the city’s sanitary land-fill. Despite enormous efforts made to recover,clean, and reprocess those tapes and parts oftapes which were recovered, more than half ofthe total data set proved irretrievable.

Subsequent to this disaster, a decision wasmade to go ahead and attempt to cIean up theCycle II data by culling the bad, remeasuring,reclassifying, and reassessing alI the data. Thetwo most serious limitations of the data aboutwhich nothing could be done had been built intothe original design and test protocoI: first, thefaihre to obtain four or five triak, and second,the complex of factors in the testing milieu

that did not insure that enough children wouldcome to maximal inspiration (TLC) immediatelybefore the full expiatory effort. These limita-tions, although recognized at an early date, havebecome increasingly apparent as the analysis hasproceeded.

The analysis and discussion of all the factorsin the testing milieu that affect the data occupymuch of this document. The consequences ofthe limited number of trials (i.e., practice trials,recorded trials, and measured trials) are also dis-cussed under two general topics: (1) criteria de-velopment and tests of reliability of trials and(2) learning curves as they influence the per-formance of maximal voluntary, cooperativeeffort on the subject’s part, especially inyounger children.

Several investigators have demonstrated thatlearning occurs with practice.7-l 0 Maximalvalues have been shown to occur most fre-quently on trials four and five, but because ofthe development of fatigue beyond trial five,values then tend to be attenuated. Since notmore than three trials were ever attempted, it isevident that the observed “best” recordings werefrequently underestimates of the child’s truefunctional state.

One of the more limiting assessment errorsmade by the initial Cycle II readers, in additionto measuring only one trial, was the lack ofdocumentation of the criteria used to judge thetrial considered best and ascertain its reliability.Given this information, a more efficient assess-ment of the data might have been made. Forexample, if the original reader had used in-correct logic to identify the best trial, then thosebest trials considered by the reviewing reader tohave been chosen correctly would have comeunder much closer scrutiny since then the cor-rect choice would have been due to chance. Themost valid method of judging reliability wouldhave been to measure the best and second-besttrials and compare the variance between them.

CRITERIA DEVELOPMENT

In view of the limitations of the data, a setof criteria was developed to evaluate the quality,reliability, and measurement precision of thespirograms.

Criteria for judging the quality of the spiro-gram required that an acceptable test demon-strate at least two trials with complete volumecurves (i.e., phases I, II, and III) and be freefrom inhalation artefacts.

Reliability of the data was satisfied when thereplicate trials of forced vital capacities, a meas-ure of a sustained expiatory effort, agreed(within a range of *1OO ml) with the originaltrial. This “window” of variance has been estab-lished by pulmonary physiologists as the limit ofbiological variation in a healthy person whenperforming the test maximally.1 1 The varianceof the flow-rate measurement (FEF2s.7 b% ) hasbeen given wider limits (+10 percent) and is con-sidered a measure of expiatory thrust since thecharacteristics of critical flow will insure relia-bility.1 2‘14 Such limits of physiological vari-ability were accepted as valid for this populationof children with full knowledge that researchdata supporting such limits were developed onadults. In the absence of any such data for chil-dren, this decision appeared to be the only logi-cal choice.

To lend precision to the measurement ofFEV1 o the technique employed to identify truezero t;me was that described in a report by theAmerican College of Chest Physicians.1 Z A linewas drawn tangent to the steepest portion of thevolume curve and was extrapolated back until itintersected with the volume baseline (figure 3).The intersect is considered the point of true vol-ume departure had there been no interveningvariables such as equipment inertia or hesitationon the part of the subject at the initiation of thetest. It is from thk point that the 1-second vol-ume measurement was made.

REMEASUREMENT PROCEDURE

After careful visual inspection of the 6,932sets of measured spirograms, it was decided toseparate them into three groups. One group of3,506 were classed as valid, meaning that theywere of acceptable quality by any conceivableset of criteria applied to them and also had beencorrectly measured. Group two consisted of al-most 3,000 spirograms which obviously hadbeen incorrectly measured and required carefulperusal and remeasuring before final disposition

6

was made. The third group consisted of spiro-grams considered of such poor quality that theywere summarily discarded.

There were two primary reasons for remeasur-ing spirograms of apparently good quality. Firstwere those tests which, although technically satis-factory, had measurements performed on thesecond-best trial. This measurement (or selection)error caused an underestimate of both the volumeand rate measurements. Remeasurements weremade on the best trial using the same techniqueemployed by the origimd readers.

The second reason to remeasure the spiro-grams was to correct the improper selection ofzero time. (This error would have consistentlyunderestimated the FEV1.0.)

The three measurements made on the forcedexpiatory spirograph (FES) were:

1.

2.

3.

Forced vital capacity (FVC), i.e., the larg-est volume measured on complete forcedexpiration after the deepest inspiration.

Forced expiatory volume at 1 second(FEVI.0 ), i.e., the volume of gas expiredover the first l-second time interval dur-ing the performance of the FES.

The forced ex~iratorv flow rate betweenthe 25-perce;t and 75-percent FVC(FEFz5.75%), i.e., the average rate offlow during the middle half of the FES.

Measurements were made by determiningthe number of millimeters traveled by thekymograph pen from the baseline to the inter-sect of the volume line at defined points by useof a dividing caliper, and converting these dis-tances to volume by multiplying by the spirom-eter bell factor. For example, the FEV1.0 is thedistance in millimeters from the l-second pointon the time baseline to the intersect of the vol-ume curve. The FVC is measured from the base-line to the highest point reached by the volumecurve. Measurement of the FEF2 5.75% is deter-mined by the volume and time increment be-tween the FVC 25 percent and 75 percent, andis expressed as milliliters per second. (Figure 3expresses it in liters per second.)

In order to avoid introducing any computa-tional error, all of the measured millimetervalues were directly recorded and later wereautomatically converted to volume and ilow

rates at BTPS (i.e., the volume of gas as cor-rected for body temperature, barometric pres-sure, saturated with water vapor) by a pro-gramed digital computer.

CLASSIFICATION OF SPIROGRAMS

After the initial sorting into three groupsand competing the necessary new measure-ments, all group one and two spirograms werereclassified according to the foIIowing criteria:

Class 1

The prime group consisted of 5,155 recordsthat demonstrated at least two trials in whichthe FVC’S reproduced within a tolerance ofapproximately 100 ml, and the slopes of thespirograms were within approximately 10 per-cent of each other. Since maximum effortresults in regdated airflow, a reliable spirometrictest would demonstrate flow rates and volumemeasurements reproducible within acceptablephysiological limits on consecutive tests.

It is a relatively easy task to choose the besttrial from a series of trials when the largest FVCand FEF2 5.7s% flow rates occur on the samespirogram. A dilemma exists, however, when thelargest FVC and FEF25 .75% values are split be-tween different trkds. At that time, for purposesof consistency, all component measurements inclass I data were always made on the trial withthe largest FVC. However, reconsidering thistoday, there is good reason to believe that ruleneed not have been so inflexibly applied.= Be-cause current refinability criteria suggest that thedifferences within these ranges are due to nor-mal physiologic variation and are not clinicallysignificant, the best FVC and FEF25 -75% valuescould have been used regardless of the trial onwhich they occurred, as long as they werechosen from the best and second-best trials thatdid not exceed the stated refinability criteria.

Class II

Reliability was not as satisfactorily demon-strated in this group (n = 648) since only the

‘The current iso-volume technique to better focus onphase III abnormalities violates these strictures, but onlywithin tight quality limits of reproducibility.

7

volume criteria were met (*1 00 ml). The slope ofthe FEF25.7 ~% of the two best trials was foundto fall within a range of 10-20 percent. In mostcases the trial used for analysis contained boththe best volume and flow rate, while in a fewcases the best slope was measured from the trialwith the smaller FVC.

To this class were also added 17 spirogramsin which the comparison trial in the test hadbeen terminated prematurely due obviously toa technician’s error. If upon careful visual inspec-tion, the reviewer determined the completedtrial would have met “primary quality” criteriahad the incomplete spirogram been permitted torun to completion, the test was classified as reli-able. The judgment was made by comparing theslope of both curves and extrapolating the un-finished slope to determine if the flow-ratedecay curve (phase III) of the spirogram ap-peared in the same position as the completetrial.

By limiting the sample to those data meetingthe stringent criteria of class I, a response rate of72.4 percent would have resulted which wouldhave impaired the sample reliability of the HESdata. However, relaxing the flow limits slightly,yet maintaining the important I?VC criteria (see“Physiology of Airflow” for discussion on theFVC’S effect on flow rate) permitted the inclu-sion of 648 class 11 spirograms. This raised theresponse rate to almost 82 percent.

Discarded Data

Class III

These data (n = 134) exhibited an intoler-ably large FVC variability, within the range of100-200 ml, though the flow-rate slopes re-mained within *10 percent of the best trial. Inmost cases the trial with the largest FVC con-tained the best flow rate, though several spiro-grams were included that definitely had thebetter slope on the trial with the smaller FVC.

Class IV

A total of 1,182 tests were eventually judgedto have no clinical value. This included thoseinitially discarded together with those sub-sequently discarded after further review and re-

measurement. The most common faults were:tracings with inhalation artefacts, incomplete ornonreproducible set of tracings, only one spiro-gram recorded, and those trials where no twotrials exhibited quality data equal to classes 1[and III spirograms. In addition, there were 187examinees with no record of ever having takena spirogram who were included in this group.

VERIFICATION AND VALIDATIONOF THE DATA CLASSI FICATION SYSTEM

The first step in testing this classificationsystem and the validity of the remeasured andreassessed data was its ability to be replicated b yan independent expert observer. A systematicsub sample of more than 700 spirograms, madeup of samples from each class, was given to amother highly experienced spirometrist to reclass-ify the spirograms using the same criteria as wehad defined them, but without knowing howthey had been previously classified. This project,was performed by Gladys Dart, Senior Pulmon-ary Technician, under the direction of Dr. GllesFilley, at the University of Colorado MedicalCenter’s Webb-Waring Lung Institute. This trialstudy was a success: it yielded a concordancegreater than 95 percent between the twoindependently classified sets of spirograms. Thiswas a critical stage in the life of the project: ifthis independent assessment had revealed amarked disagreement between the two expertreaders, subsequent analyses would have beenfutile.

CRITERIA FOR MERGINGTHE DATA CLASSES

Having created the four classes of data, itwas necessary to evaluate them in terms ofacceptability: that is, which of the data classeswere good enough to be considered as valid esti-mates of the best efforts (and/or true physio-logic capacity) of the children?

At this point, the authors were faced with aproblem of the cost/benefit nature which was a,hallmark of the entire project. To have thrownout too large a portion of the available data,would have severely weakened our confidence

8

that the remaining sample represented the U.S.population of 6-1 l-year-olds. To have kept toolarge a portion of the available spirograms wouldhave made the technical quality of that samplehighly suspect; so the solution was to strike themost satisfactory bahmce between quality andquantity (i.e., spirometric quality and samplingqudlty).

In order to achieve an optimal balance forthe best possible population estimates, a varietyof distributions was examined to determine thekmd and extent of differences between theclasses. In particular, differences were sought be-tween quality classes of FVC and FEV1.0, byregion, income, education, IQ (as measured bythe Wechsler Intelligence Scale for Children),and stature. All of these distributions were fur-ther crossed by age, race, and sex to insure thatany differences detected could be attributed asspecifically as possible to their source. Partialtabulations for some of the more important vari-ables involved in this massive effort can befound in tables 1-9.

The distributions by region, income, educa-tion, and IQ did not differ between classes inany regular fashion, nor did mean statures differsignificantly. There were no consistent dif-ferences between means of the FVC’S andFEV1.0’s for any of the classes where these dataexisted.

The only important differences were foundbetween the classes I, II, and III and class IV data(which contained cases with missing tests andtests of no clinical value) where substantial age,race, and sex effects .were demonstrated. Thepercentage of each age group in class IV declinedwith increasing age, from a maximum of 26.4percent for 6-year-olds to a minimum of 12.1percent for 1 l-year-olds. Also, 22.3 percent ofthe black children fell in this class, while only15.7 percent of the white children were includedhere. The difference in proportion by sex wassmall (17.0 percent for females versus 16.2 per-cent for males), but in the expected direction.This class was later subjected to an intense andlengthy scrutiny in an attempt to discover causa-tive factors which might account for a subject’sinclusion in class IV. Although class IV chiklrendiffered from those in classes I-III on severaIvariables (e.g., they were slightly shorter thantheir cohorts), no factor or combination of fac-

tors was found that exclusively identified classIV children. Consequently, it was not necessaryto modify the imputation procedure to adjustfor any unique characteristics of this group.

Classes I, II, and III were essentially alikedemographically and physiologically. Class IValone was different.

The final decision, then, was to combineclasses I and 11 as our basic working data set.The data in class III were less than 2 percent ofthe original sample but evidenced a seriousmethodological faiIing. The spirometric valuesfor these 134 subjects were discarded and laterreplaced by imputed values, as was the case forall class IV subjects.

STRENGTHS OF THE DATA

Despite the known deficiencies of these datathe distributions of the component parametersof the forced expiatory spirogram are the mostrepresentative population estimates ever ob-tained on children. The 7,119 children examinedin HES Cycle II are representative of 23,784,000noninstitutionalized children, ages 6.0 to 12.0years residing in the coterminous United Statesin 1963-65. In addition to the enormous sam-pIing strengths of these HES data, a large batteryo f psychologic, physiologic, anthropometric,demographic, and sociologic data were also availa-ble for each person. This mass of additionalinformation contributed immeasurable strengthto the data amdysis since it permitted the devel-opment of FVC and FEV1.0 data using imputa-tion techniques on those 1,316 subjects who didnot have acceptable spirometric data; and, ofcourse, these variables can be cross-tabulatedand correlated in detailed analyses.

Several methods of imputation were con-sidered, but stepwise multiple regression waschosen as most appropriate for FVC andFEVI.0. The appendix in the Series 1 l-No. 164paper on children’s FVCl includes a detaileddescription of the rationale and details of thisimputation process. The 5,803 cases with ac-ceptable spirometric values were the data baseupon which the imputed vzdues were generated.

It was determined that from the many physi-ologic and demographic variables avaiIable asregressors, 37 of these (see section on imputa-

9

tion in appendix of reference 1) might manifestsignificant correlations with the spirometncparameters. The values for these 37 independentvariables and the two dependent spirometricvariables were input to a packaged multiplestepwise regression procedure, and the equationsin the appendix of reference 1 were the result.

After the FVC’S and FEV1.0’s were imputedfor the 1,316 subjects who did not have accept-able spirometric data, the validity of the imputa-tion process was verified in the several ways justdescribed. Distributions of the imputed valuesby age, race, and sex were compared with thoseof the basic data set of 5,803 (i.e., ‘(acceptable”population) and no significant differences wereshown by the sign test at the 5-percent level.Nor were there any significant differences whenthese distributions were further crossed by sit-ting height (the first variable to be included inboth equations). There were no apparent dif-ferences in the relationships by age, race, andsex between the imputed and nonimputed datasets within classes.

Combining the data sets resulted in age-race-sex specific mean values very similar to those ofthe original nonimputed data set. However, themean values for combined age or race or sexgroups were reduced somewhat. This would beexpected since younger children, females, andNegroes (all of whom tended to have lowervalues than their respective complements) wereoverrepresented in the “unacceptable” class.Consequently when the data sets were com-bined, more lower values were added to the finaldata set than higher ones, thus lowering anyoverall statistics that did not control for age orrace or sex effects.

COMPARISON WITH OTHER DATA

Of course, comparison with data from otherstudies is one of the important steps in vali-dating one’s own data but such a comparisonwas almost impossible in 1970 and 1971. Thepublished data on spirometry in chkiren wasthen and remains now sparse, with conflictingestimated values and of quite uneven quality.Besides the paucity of solid comparative data,the important distinctions between data col-

lected in a survey and those collected in a labo-ratory are sometimes ignored. (However, becauseof vast improvements in electronic equipmentand development of spirometric technique in asurvey setting, these differences are not as greatnow as they were before 1970.)

In general, spirometric data obtained in aclinical laboratory setting have two distinct ad-vantages: a better motivated and more willingsubject on the one hand, and time and oppor-tunity to establish rapport, give more thoroughinstruction, with better opportunity of obtain-ing a valid test, on the other hand. Most peoplecoming into a laboratory are usually there for aspecific purpose and have something to gain byundergoing the tests. Time is available to individ-ually explain and demonstrate the test pro-cedure in as much detail as necessary and to runthrough several practice procedures. The subjectmay return another day for additional trials, ifnecessary. In addition, the subjects are selected:they self-select themselves to come to that par-ticular laboratory and because the laboratoriesare not trying to obtain representative popula-tion samples they can simply discard bad data.They will exclude from their “normal” valuespeople with very low IQ’s, the hostile, the indif-ferent, the suspicious, the frightened, and anyothers who are either incapable or unwilling togive a satisfactory test response even after re-peated attempts. Additionally, because mostsubjects’ procedm-al errors give underestimates,and the errors are additive, especially in theparameters involving volume measurements,there is a general rule of thumb: all else beingequal, the larger of two volume measurements onthe same subject is likely to be the more ac-curate. (This special set of circumstances tendsto increase the clinical laboratory spirometrilcvalues over those obtained in a survey setting.)

An unusually comprehensive and very usefulhandbook of laboratory techniques, “PulmonaryFunction Testing in Children: Techniques andStandards,” by Polgar and Promadhat was pub-lished in 197 l.ls However, in a section entitled,“Standard Values,” Polgar and Promadhat ambi-tiously attempted to bring together most of theearly literature on childhood spirometry andsynthesize the findings into one set of compositestandard values. They were prompted to such an

10

effort by the realization that so-called “normal”values from the various indkidual studies couldnot be considered representative of generalpopulation values. By combining the variousstudies they had hoped that the composite nor-mal predicted values might take on more of thecharacteristics of a representative sample thatcould be generalized to all children. This hopewas not realized.

For vital capacity, data on 45,000 subjectsbetween the ages of 3 and 19 years were as-sembled. Children comprising the test popula-tions came from schools, orphanages, and hospi-tals, and originated from nine different countriesof four continents. Although all measurementswere made on wet systems, there were enormousand immeasurable variations in both the char-acteristics of the instruments, in testing method-ologies, and measurement techniques among thevarious laboratories. Although the majority ofmeasurements were made in a sitting position,several were made either in the semirecumbentor standing positions. All semirecumbent valueswere corrected to sitting position vital capacityvalues before being averaged with standingvalues. Data were corrected to BTPS. The com-posite mean FVC’S are 100-150 ml higher thanthose observed by this survey for children of thesame age and sex.

Polgar and Promadhat did not satisfactorilydistinguish between survey and laboratory datanor did they consistently define important dif-ferences in technique when combining and ad-justing data. This makes precise comparisonswith their data very difficult. But more restric-tive as reference data was the statistical handlingand presentation of the data.

For example, when the mean FVC valuesfrom HES were directly plotted onto the graphsas taken from the book,l 5 the HES means wereat the line designated as 2 standard deviationsbelow the “Polgar composite means.” After sev-eral hours’ work, we were able to reconstructhow the graphs were made: instead of using anyestimate of variance from an actual study, thestandard deviation was calculated using the sum-mary means of the separate studies as data; con-sequently, rather than this being any measure ofpopulation variation, it was a standard deviationof means from various studies. Borrowing the

standard error of FVC’S from the HES data, itwas then found that HES’ mean FVC’S wereonly 1 standard deviation less than Polgar’s,rather than 2. Because of this evidence of amajor statistical flaw and the fact that there isnot enough documentation of other statisticaltechniques used attempting to arrive at the com-posite values, this section of the book cannotreliably serve for epidemiologic comparisons.

Polgar’s published “normal values” would bemore appropriately viewed as estimates represen-tative of his own laboratory findings-for alltheir strengths and weaknesses. On the otherhand, the remainder of the book has great valuewhen used as a compendium of techniques em-ployed in assessing all aspects of pulmonaryfunction in children.

ANALYTIC PROBLEMS

The spirometric data obtained by this surveypresented a series of problems so challenging andwidespread in nature that a proper analysis re-quired the use of a variety of analytic techniquesand substudies and a great deal of time, pa-tience, and effort to produce a report that mightbe both useful and informative. AU of the var-ious major problems were not immediatelyapparent; some only surfaced as the analysisproceeded.

Already detailed in this report was the prob-lem encountered with initial measurement andreview of the original 7,119 spirograms, and theremeasurement of several thousand spirogramsthat had been incorrectly measured. After care-ful development of volume and flow reliabilitycriteria, all available spiroqams were classifiedby quality. Verification of the classificationsystem was accomplished by having a subsampleof spirograms read and classified “blind” by asecond expert spirometrist, as described earlier.The high level of concordance demonstrated(over 95 percent) encouraged the authors tocontinue with the analysis.

In spite of the care taken in this verificationstep, we knew that a residual group of proce-dural failings inherent in all the data would per-manently defy adjustment. A practice trial,when done at all, had been frequently inade-

11

quate. Too few trials had been taken to insure amaximum effort. Since only the best trial wasmeasured, intratrial comparisons were impos-sible. And finally, a strong possibility existedthat some proportion of the subjects failed toreach their total lung capacity. (As will be dis-cussed, the new visual criteria are vulnerable tothis type of error; they are incapable of eitherdetecting or adjusting minor errors of this type.)In the absence of further research in these areas,a quantification of these effects is impossible.

The next major project was the evaluation ofthe newly classified data set in order to optimizemerging and to determine the validity of merg-ing the classes. As described previously, thisanalysis revealed no marked differences betweenthe groups where spirometric data were avail-able. The greatest sample size (n = 5,803) wasachieved with the least dimunition of quality bycombining classes I and II. This data set wasused to generate equations to impute spiro-metric values for the 1,316 subjects who didn’thave acceptable spirograms. An earlier sectionhas described the procedure used to impute theFVC, FEV1. o, and FE F25.7s% measurementsfor the 1,316 subjects, and the verification ofthat procedure.

During the analysis and development of thespirometric population estimates, serious prob-lems with the FEF25.75% became evident. Re-gression lines of this variable against age wereextremely unstable, particularly for blacks andyounger children. No immediate explanation forthis behavior could be found; but when diggingdeeper for answers, several more immediateproblems with the two other parameters wereuncovered: (1) A large proportion (28 percent)of the original sample (n = 5,803) had an FVCequal to FEVI. o (i.e., the forced expiatoryspirogram was completed in less than 1 secondand hence, for these subjects, the FEV1.0 is ameaningless parameter because the required timeduration is too long); this defect was sex-race-age related (i.e., girls, Negroes, and younger chil-dren were overrepresented). (2) The mean FVC’Sby age, race, and sex are probably underesti-mated. The effect of these problems onFEF2s.7s% are explained in the following sec-tion, “Interaction of Volume and Flow,” but

their significance to the entire data set tran-scends their effects on FEF2 5-7570.

A study was immediately undertaken todetermine if thk FVC-FEV1 o phenomenon wasthe result of the subjects’ failure to reach resid-ual volume (RV) because of premature termina-tion of expiatory effort, and, if so, to quantifyits contribution to underestimating FVC for thedata set. (A more detailed description of thisand subsequent substudies follows in a later sec-tion.) To this end, a proportional sample of theavailable tracings was reevaluated by two expertspirometrists paying special attention to theterminal end of the curve.

Two more substudies were also performed toprovide an accurate idea of the distribution ofvalid FVCT ‘s, particularly the proportion lessthan 1 second. The first, conducted on a verysmall sample, under optimal conditions, con-firmed that a valid FV~ of less than 1 secondwas possible in children of thh young age. Asecond, larger sample provided a distribution ofFV~ ‘s, and also provided FVC and FEV1.9data for comparison both with the HES esti-mates and Polgar’s published values. Finally, afourth sub study was performed to measure theeffect on TLC of having used the “closed” ver-sus the “open” system during inspiration inCycle II.

Before describing the details of the sub-studies, it is necessary to understand some of thecomplex interactions of the lung function meas-urements that are produced by variations in theperformance of the forced expiatory spirogram.

Literature dealing with the performance ofthe FES frequently ascribes certain componentmeasurements as being either effort dependentor independent. Such statements need to beviewed with caution because specific dynamictest conditions must first exist before claims ofeffort independence can be made; viz, an FESmaneuver performed by a normal lung gives atrue measure of vital capacity only if the in-spiratory phase is taken completely to the totallung capacity (TLC) and the expiatory phase toresidual volume (RV). The failure to achieveeither parameter causes an underestimate of thetrue vital capacity and distorts almost all of thecomponent dynamic measurements of flow rate.

12

INTERACTION OF VOLUME AND FLOW

The morphology of the FVC curve is a sen-sitive indicator as to whether or not the RV wasreached by the pattern described by airflowbecause it proportionally diminishes until resid-ual volume is achieved. The airflow from thegradually smaller airways in the peripheral por-tions of the lung is characteristically displayedby a smooth decay curve that finally plateaus atRV. Absence of this terminal decay curve isstrong evidence that the expiration was ter-minated prior to reaching RV (figure 5), causedeither by abrupt closure of the glottis or bycessation of expiatory effort.

Unfortunately, no accepted criteria have beendeveloped that permit a similar visual assess-ment to be made as to whether or not the TLCwas achieved during the inspiratory phase of thetest. Both errors (failure to reach TLC and fail-ure to reach RV) not only reduce the FVC butmay also reduce the forced expiatory volume atvarious time intervals (FEVT ). Either one ofthese procedural errors, in addition, effectivelycompresses the volume displacement between

the onset of the curve and its termination, andspuriously elevates these FEVT /FVC ratio meas-urements. Such distortions destroy the sensi-tivity of these measures of airway resistance.

In the section on technical background, theconcept of critical flow and its importance tothe validity of flow-rate measurements has beendiscussed. If the FES is correctly performed andcritical flow is achieved, then measures of flowrate are accurate (i.e., FEF25.75% ). However, ifthe FVC is attenuated due to failure to come toTLC or expire to RV, flow rates will be eithererroneously high or low, even in the presence ofcritical flow (see figure 5). When the FES is per-formed correctly, the FE F2s.7s% measurementfalls within that part of the curve considered tobe in critical flow (phase II). However, when RVis not achieved, this flow measure is pushedhigher up the FES curve which includes a largerpercentage of phase I of the spirogram. This nowartificially elevated flow rate picks up anotherundesirable characteristic, that of variabilityy,since it is computed using in part the highly vari-able (effort-dependent) portion of phase I. Anopposite effect, however, takes place when fail-

/ w True FEF23 ,5%

?~0>

FVC

———.—.——

LCTIME

Normal FESla)

A?uftc!a!!y elevated FE F25,5%

——.——— — 75%

F Vc

———__—— - 25%

TLC TIME

RV attenuated F ESlb)

TLC.mtenuamd F ES(c I

Figure 5. Effect of TLC and RV attenuations of FES on FEF ~5.75% maasure of flow rate. (Note increased slope of flow-rate line in (b)

and decreased slope of flow-rate line in (c) as compared with (a))

13

ure to reach TLC causes an attenuated FES. Theflow-rate measurement is pushed down the curveso that it now includes not only phase II, butsome of phase III as well. This effectivelyreduces the flow rate, and also adds stability tothe measurement since both phases H and III areincluded in the less variable effort-independentportion of the curve. Paradoxically the distor-tion to FEV2s.7s % is less if both errors arecommitted on the same trial: in other words,these two effects are counterbalanced and some-what neutralized when an attenuated FVC hasequzd components of both procedural errors.

Current practice attempts to get around thisprobIem by use of an iso-volume curve wherebya resting vital capacity is obtained independentlyon one trizd and then partial expiatory effortsare subsequently obtained and measured in thecontext of the resting vital capacity.

SUBSTUDIES

Miscellaneous Substudies

The first of the substudies was designed toclosely e x amine the phenomenon of theFVC = FEVI.0, and to determine its effect onthe main body of the data.

A systematic subsample of 205 subjectsfrom the 1,624 HES subjects with FVC =FEVI.0 data was chosen and was found to berepresentative of its parent group for the var-iables of age, sex, and race. These data were in-tensively reviewed by Drs. Alan Palmer andDavid Discher to determine the extent and causeof the FVC = FEV1. o phenomenon. There was aworking hypothesis based on the belief that allchildren should be able to maximally expire formore than 1 second. On this assumption, anyspirogram with an FVC = FEV1. o would beprima facie evidence that the test effort hadbeen incomplete due to failure to reach residualvolume which prematurely truncated the decaycurve and would therefore be technically un-acceptable. The consequences of such a findingwould have been threefold:

1.

14

It would go a long way toward explain-ing the apparent FVC underestimates.

2.

3.

It would explain why FEV1.0’s weremore similar to FVC’S than was reason-able, particularly for the younger ages.

It would Partiallv explain the erratic be-.havior of ~he flow-ra~e data (as explained,in the previous section). Conversely,such a finding would have had a veryserious implication, so serious as to chal-lenge the validity of the entire resezucheffort to that date. Specifically, it wouldhave discredited the entire spirometryclassification system that had been creat-ed by evidencing that a high percentageof truncated spirograms had slipped bythe rigorous screening procedures usedto preclude invalid tests.

Prior to the reexamination and classificationof the 205 spirograms, a set of morphologic cri-teria was developed that permitted consistentdecisions on the technical quality of the ter-minal portion of the recorded FES. Pattern-1spirograms included all of those which, uponvisual inspection, contained all three spirometricphases, particularly a terminal section (phase III)that showed a smooth deceleration of volumeover time, to an eventual plateau (zero changein volume). Figure 6(a) demonstrates two com-monly seen decay patterns, both acceptable aspattern-1 spirograms.

Pattern-2 spirograms differed by having apremature termination of airflow during phase IIor III of the curve indicating that the test sub-ject had locked the glottis, thus forcing anabrupt deceleration of airflow to zero. The sud-den plateauing of the volume signal with nointervening decay section was considered evi-dence that the residuil volume (RV) wasprobably not attained; therefore, the test wasdeclared to be artificially attenuated. Figure6(b) shows the morphology of unacceptablepattern-2 spirograms. Pattern-2 morphology, ofcourse, can also exist in spirograms with an FVCgreater than 1 second, but because this sub-sarnple was limited to those spirograms with anFVC less than 1 second, none was encountered inthk investigation. To extend the reexaminationfor all pattern-2 errors in the entire remainingdata set (n = 5,598) would have been pro-hibitively expensive in time and cost.

RV

~,().”,o”ta, W

2

30>

Acceptable curve

TLC

TIME(a}

Termmalion recomplete

No ro.ndout present

ii>

:>

ITIME

{b)

Fiaure 6. FES curves: (a) Dattern l–acceptable decaycurves;b) PetterflZ–curvesPreMatUrWterminated.[Notethatdew curvesareincomplete or absent)

This investigation had surprising results:only 18 percent (n. = 36) of the 205 subsamplespirograms had a pattern-2 morphology! Thisunexpectedly small percentage of RV-deficientspirograms, although forcing a drastic reassess-ment of our assumptions and further investiga-tions, did vindicate the visual classificationsystem which we had devised. (The prevalenceof the pattern-2, premature termination of ex-piatory flow error probably far exceeded 50percent in the group of spirograms earlier dis-

caded as technically unsatisfactory.) Because inlarger spirograms it is easier to detect pattern-2errom, and because the larger FES tends to in-dicate a better performance containing fewertechnical errors, it would be unreasonable toassume a prevalence of greater than 18 percentin the larger part of the data set (i.e., in whichFVC is greater than FEV1.0 or l-second dura-tion). Therefore 18 percent (15-20 percent)appears to be a sound estimate of the prevalenceof pattern-2 errors in the data set.

15

The pattern-2 curves were then reviewed toquantify the amount of underestimation of theFVC due to truncation by use of a techniqueknown as the measurement of the “angle of in-cidence. ” This procedure required that at leastthree-fourths of the decay curve be present onthe trial measured, and that another trial belong-ing to the same subject be present with a fulldecay. (The latter requirement is helpful indetermining the shape of the estimated decaycurve. ) The difference in millimeters betweenthe estimated (extrapolated) FVC and the ob-served FVC was determined and expressed as apercentage of the observed value (figures 6(a)and 6(b)).

This technique projected underestimatedvolumes ranging only from 3 percent to 7 per-cent, averaging about 5 percent.

A 5-percent underestimate occurring inapproximately one-fifth of the data set at themost would result in the contamination of thefinal data set by pattern-2 errors causing only 1percent or less underestimate of the averageFVC.

The unexpectedly small frequency of pat-tern-2 curves and their small magnitude ofunderestimate strongly suggested that most ofthe problem was probably due to technicalerrors committed at the beginning of the spiro-gram rather than at the terminal part. This con-clusion appears even more plausible after carefulreview of several separate items of data, i.e., thedistribution of FVC = FEVI.0, the distributionof pattern-2 obtained from thk substudy, andthe patterns of the regression lines of the flowrate. The most frequent occurrence of theFVC = FEV1.0 phenomenon was seen to occurin the youngest age groups (6- and 7-year olds) infemales and among Negroes. Since most of thepattern-2 data were seen to occur in 8- and9-year-olds, in this subsample it can be conjec-tured that much of the attenuation of FVCvalues for 6- and 7-year olds seen in this maindata set was caused by failure to achieve TLC.

Coefficients of variation derived from datain tables 10 and 11 show that flow rates forNegroes are extremely variable between the agesof 6 and 8, and this is also true, to a small ex-tent, for white females, Because of the effect onflow rates of the reduced FVC (as discussed),the erratic pattern of the curves may be the

result of both types of FVC errors perturbatingthe estimated flow rates.

The failure of this substudy to adequatelyexplain the cause of the high percentage of datain which FVC equals FEV1. o and low FVC valuesin the HES sample indicated the need to pursuethe following additional questions:

1.

2.

3.

Is the assumption that almost all youngchildren should be able to maximally ex-pire for more than 1 second correct? Inother words, is it possible to obtain anoptimally performed FES, where all testcriteria have been met (TLC, criticalflow, and RV), with attainment of aproper FVC, in less than 1 second?

If so, what is the expected frequency ofFVC = FEVI.0 in the youngest children?

What is the expected distribution ofFVC~ by age (i.~., the shape of the dis-tribution curve and the actual timevalues as obtained under ideal testing cir-cumstances) ?

(To go back and remeasure each time dura-tion accurately by hand on 5,803 Cycle II trac-ing would not only have been an enormous lo-gistic task but it would have also begged thequestion: “Do these FES tracings in Cycle Hrepresent ideal or even adequate testing circum-stances-even after all of the work to screen outthe bad trials?”)

In order to answer the first question, we hadto fmd one or more children over 6.0 years ofage who, under optimal testing circumstances,and in the opinion of highly skilled spirom-etrists, completed a proper FES in less than 1second. (Corollary: No matter how hard andeffectively the children tried, their physiologicventilator capacity could not sustain an effec-tive expiatory effort, even after maximal in-spiration, for 1 second.) In testing 10 con-veniently available children between 6 and 8years old, one child was found to clearly andunequivocally meet these conditions. This find-ing, of course, negates the working hypothesis(stated above) that all spirograms with FVC~ lessthan 1 second are, prima facie, technically in-adequate spiropams in chddren over 6 years ofage.

16

Salt Lake City Substudy

WM this information, a second study wasdevised to answer the second and third questionsusing an at-hand sample of 79 six- and seven-year-olds. The survey was performed by highlycompetent technicians on equipment capable ofproducing the same parameters that were earliermeasured. A number of factors combined to makethis testing situation almost unique: (1) The tech-nicians who did the testing were very knowledge-able, very well trained, and highly skilled in ad-ministering the FES pulmonary test. (2) Theequipment on which the FES was taken wasof the most modem design, reflecting every ad-vance in the state of the art. (3) Because thechildren were from two cktsses in the same gradeat the same school, a lot of the anxiety whichtypically vitiates performance on the FES wasabsent; i.e., there was a good deal of peer sup-port and friendly competition. (4) The data col-lected were analyzed by the most modem com-puter analysis program availabIe, reflecting everyadvance in the science of spirometry up until thepresent. (5) AU the data were collected in a veryshort time, a single day. This circumstance con-tributed to the overall quality of the data byproviding a great deal of consistency insofar asbarometric pressure, temperature, technicianperformance, and other factors were concerned.

(6) Where only three trials, at the most, weretaken in the HES, five trials were taken on the79 children, and as might be expected, per-formance generally improved with the increasednumber of trials, due to a practice (or learning)effect.

Since the new spirometric data were to becompared with the HES spirometric data, it wasimportant to eliminate (or at least quantify theeffects of) differences in factors that might haveinfluenced spirometric performance. For in-stance, the data indicated that the race and sexcompositions of the two samples were differentand it may or may not have been necessary tocompensate for the dissimilarities.

Relevant factors may be of two generalkinds, demographic or physiologic. While a largeamount of this type of data was available foreach of the HES subjects, relatively little wascolIected on the 79 subjects who were all whiteand residents of a SaIt Lake City (SLC) suburb.Among demographic data available for the lattergroup were age, race, and sex, and some fairlysubstantial data concerning the socioeconomicstatus of the group as a whole. The only in-dependent physiologic variable measured wasstature. Preliminary demographic distributionsfor the SLC sample are given in table A.

It has been demonstrated that age, sex, race,stature, and to a lesser extent, socioeconomic

Table A. Frequency distribution of standing height, by ege, sax, and sex end age: Salt Lake City, 1974

Age, sex, and sex and age

Total .. .. .. .. .... .. ...... .... ............ ... ....... ...... .... ........... ..

Age—

6 ymrs . ..... ........... ... .. ...... ..... ..... ..... ............. .... .... . .... .. .... ........7 years .... .. ............ ... ............. .. ........ ............ ..... ... . ..... ...... ... ....

Sex—

Male .. .. ............ .. ............ .. .. ......... ..... .... .. .. ............ .... .. .... ...... ..Female ... ....... . .... ........... ... .. .. .. .... .... ...... .... ............ .... .. ... ..... .. .

Sex and age

Male, 6 yeers .... ........ .. .. .................. ...... ..... .... ............... ....... ..Male, 7 years .. .. ....... ...... ..... ........ .... ..... ..... ...... .... ............ ..... . .Female, 6 yaars .. .. .... ...... ..................... ...... .... .. .... ........... .... ...Female, 7 years ... .... .. ..... ................ ..... ..... ....... .... ........... .... ...

Total

79

3049

3544

z1528

—42—

1=

1

1

1—

—44

—

6=

32

14

1

22

—

—46

—

1=

1

1

1—

Standing height in inches.46

—

8=

:

62

3311

—

—47

—

11=

83

65

4241

—

—46

—

17=

512

1:

3428

—

—49

—

11=

56

47

223

,4—

—50

—

13=

310

76

2515

—

—51

—

9=

27

45

423

—

—52

—

2=

2

2

2—

53

1

1

1

1

17

indicators are all related to spirometric perform-ance.

Age.–It has been noted that for childrenthere are positive relationships between age andFVC and age and FEVI.0. The mean age of SLCand HES 6- and 7-year olds are:

Study 6 years 7 years6 and7 years

SAC ........................ 6.80 7.30 7.12HAS ........................ 6.50 7.50 7.00

Treating the two age groups separately wouldrequire estimating the adjustments necessary tomake the two samples comparable. But the dif-ferences between the combined age groups wererelatively slight, so the age groups were com-bined, and the comparisons were made betweentwo groups rather than among four groups.

Sex.–The relationship between sex andspirometric performance (at least in adults) isthat maIes have greater vzdues than do femaIes,given the same structure and age. The twosamples are compared as follows:

Study Males Females

SAC ...................................... 44.3% 55.7%HES ....................................... 50.8% 49.2%

The mean statures and ages by sex for the SLCsample were:

Age and stature Males Females

Mean age in months ............... 85.1 85.6Mean stature in inches ............ 48.3 48.2

Although the proportions by sex for the twogroups are not precisely comparable they arefairly close. Within the SLC sample the sexes areessentially identical as far as age and stature areconcerned.

Race. –This variable was related to spiro-metric performance. Negroes did significantly lesswell than whites on both FVC and FEV1.0. TheSLC group was all white, but since the percentof blacks in the HES sample was relatively small

(10 percent), no attempt was made to adjust fordiffering racial comparisons.

Stature .–This variable is highly and posi-tively related to both FVC and FEVI.0 (r= 0.69,0.67, respectively). Although HES data indicatethat sitting height may be a slightly better pre-dictor of these parameters (and in fact mayeliminate much of the race effect), it was notmeasured on the SLC children. The mean stand-ing height of the SLC sample was 48.27 incheswith a standard error of 0.243 inch, while thatof the HES sample was about 47.68 inches witha standard error of about 0.103 inch. The two,means were not significantly different at the5-percent level, but the difference of about 0.6inch is worth noting. The difference may be afunction of the secular trend for mean heights ofchildren to increase with the passage of dec-adesl 6 and there was a 10-year lag between theHES and SLC studies. Using a regression line pub-lished by HES earlier,l 7 it is possible to estimatethis effect to be about 0.5 inch. The differencesmay also be partially explained by consideringthat alI the SLC subjects were volunteers, whilesome of the HES children were examined onlyafter strenuous persuasion. Finally, standingheight is significantly related to the last effect tobe considered.4

Socioeconomic status.–Using published HESestimates,l T we know that there is a positiverelationship between height of child and paren-tal income and between height of child andparenta.I educations For instance, the meanheight of a 6-year-old whose family’s income is$500-$999 is 45.2 inches, while that of a 6-year-old whose family income is $15,000 ormore is 47.1 inches. It is quite conceivable thatmuch of the observed height difference betweenthe two samples can be accounted for in thisway, since the SLC suburban residents weresomewhat more affluent than the general U.S.population, being composed primarily of profes-sionals associated with the University of Utahand “corporate executives .“ It is known that themedian income for the HES sample was in the$5,000-$7,000 range and that the 6- and 7-year-old boys and girls in this category had meanheights, respectively, of 48.03 and 47.34inches. 1T On the other hand, the SLC sample

18

would correspond best to the $10,000-$15,000range, for which the mean heights were about48.13 and 47.93 inches. The weighted HESmean for boys and girls combined was 47.71inches, while that for the SLC distributionapplied to the HES means was about 48.02inches. The conclusion reached was that socio-economic differences might account for abouthalf the observed difference in standing heightbetween the two samples.

Figures 6 and 7 in reference 1 show the re-gression of FVC against standing height. Althoughthe values themselves may be suspect, the de-picted slopes are probably near the truth, so thatthe graph can be used to determine what effectthe various height differences have on the meanoverall FVC’S. Since the lines are nearly linearand parallel, any two height benchmarks uni-formly applied to each Iine will describe thesame difference in FVC. Using the overall meanheights for HES and SLC, 47.63 and 48.27 inches,respectively, a net difference of about 40 ml isnoted.

Best trz”alselection, SLC.–Prior to displayingthe distributions of the FV~’s and FVC’S, andFEV1.0’s of the SLC sample, some mentionshould be made of the manner in which the bestof the five trials of each SLC subject was chosen.Although the procedure has been described else-where,G a brief review follows to help the readerunderstand the subsequent discussion.

Predicted values for FVC and FEVI.0 werecalculated for each subject, based on equationsfound in the Journal of Occupation Medicine,September 1972, in an article entitled “Develop-ment of a New Motivational Spirometer.”G Al-though these equations axe intended for use withadults only, the use of any constant worksequally well for the best trial selection pro-cedure.

Standard deviations from the predictedvalues were calculated for the FVC and theFEV1.0 of each of the five trials.

The two z values were summed for each reli-able trial, and the trial with the most positivesum was declared the best.

Best trial selection, HES.–For the HES data,the better trial from the two (or best trial ofthree) available tracings was selected by a high-

Iy experienced spirometrist after being subjectedto the consistency criteria described earlier inthk report. Both the SLC and HES proceduresevaluated the spirographic curves in terms of thesame criteria; i.e., maximum FVC, maximumflow rate, and some measure of consistency, sothat “best trials” were selected in a comparablemanner.

The distributions of FV~’s for the SLCsample are shown in table B. Ordy 4 of the 79cases (or 5.1 percent) had an FVC time less than1 second. This compares very unfavorably withthe HES value of 709 out of 1,784 six- andseven-year-olds (39.7 percent). The z value ofthe significance test for the difference betweenthe two proportions is 12.662, more thanenough to reject the null hypothesis of no differ-ence (p < .0001).

So, what has happened? The first conclusionthat comes to mind is that a mass screeningmechanism such as the Health Examination Sur-vey fails to eIicit the same quality performancefrom a group of examinees as did the optimaltesting situation (SLC). But examination ofother data suggests additional possibilities. Ofparticular interest is the possibility that a prac-tice effect exists; i.e., a subject becomes morefamiliar with the test with repeat trials and con-

Table B. Frequency distribution of FVCT (best of five trials), byage and sex: -Salt bke City, 1974

‘“” B

rTotal ... .. .. ...... ............ ... 15

0.8-0.8 second ... .. .... .. .... .. .. .. .. ... -0.9-1.0 second ... ... ... ............ .... 11.0-1.1 seconds ... .. .... ..... ..... ..... 11.1-1.2 seconds .... .... .. .... ...... .... 21.2-1.3 seconds .... .... .. .. .. ...... .... 21.3-1.4 seconds ........ .. .... .... .. .. .. 11.4-1.5 seconds .. ........ .. .. .. .... .... -1.5-1.6 SS!COndS . . . . . . . . . . . . . . . . . . . . . . . . 1

1.6-1.7 seconds ... .......... ........ ... -1.7-1.8 seconds ..... ............... .... 11.8-1.9 seconds .. .. ................ .... 11.9-2.0 seconds . .. . ... ............. .... 22.0 seconds and over ............... 3

15

1111

11

22

5

20128

1

1 2

1 111

2 42 11 11 3

512 9

19

sequently does better on later trials. The distri-bution of the number of the best trial was tabu-lated to investigate the question:

Best tn”alPercent ofoccurrence

1..................................................... 6.32..................................................... 19.03..................................................... 12.74 ..................................................... 22.85..................................................... 39.2

Thus 74.7 percent of best trials were third,fourth, or fifth. And since the HES used onlytwo or three trials, it is evident that as much asthree-fourths of the time even the best of therecorded HES trials did not reflect the child’strue capability, in spite of having achieved a vis-ual level of reliabiM.y.

In the SLC data, the better of the first twotrials was chosen by the “sum of z’s” method(after all subjects with unreliable pairs of trialshad been rejected), and FVCT’s were taly.dated.(See table C.)

This resulted in 9 out of 59 (15.3 percent)subjects having FVCT’s less than 1 second. The zvalue for the difference of the SLC and HESproportions (39. 7 percent and 15.3 percent) is4.821, while the z value for the difference be-tween the two SLC proportions (15.3 and 5.1percent) is 1.924. The first is significant at thel-percent level, while the second is significant atthe 10-percent level,

Table C. Frequency distribution oftrials): Salt Lake C

FVCT

0.7-0.8 second .... ...... ....... ..... ...... .... .0.6-0.9 second ...... ... ..... ...... ... ... ..... .0.6-1.0 second .... .... .. ... ...... ......... ....1.0-1.1 seconds ... .. .... .... ...... .......... ..1.1-1.2 seconds ... .. ... ............ ..... ......1.2-1.3 seconds .... ........ .... .. .. .... .... ...1.3-1.4 seconds . .... .... .... ..................1.4-1.5 seconds ... ............................1.5-1.6 seconds ... ............................1.6-1.7 seconds .................. .. ...... .... .1.7-1.8 seconds .............. ...... ...........1.8-1.9 seconds ......... .... ....... ...........1.9-2.0 seconds ... ...... ...... .... .... ....... .2.0 seconds and over . ... .. .... ........ .... .

NOTE: n = sample size.

VC~ (better of first two, 1474.

n

—

2341342323635

18—

Per-cent

3.35.16.81.75.16.83.35.13.35.1

10.25.18.5

30.5

;umulative—

n

—

259

10.13171922242733364159—

Per-cent

3.38.4

15.216.922.028.832.137.240.545.655.860.669.499.9

The mean values of FVC and FEV1.0 alsodemonstrated that the SLC children were veryunlike the HES sample in terms of spirometricperformance. Using the better trial from onlythe first two of the five, the mean Salt Lake CityFVC was 1,546 ml with a standard error of30.38 ml. The mean Salt Lake City FEV1.0 was1,395 ml with a standard error of 49.05 ml. Forthe HES sample (n = 7,119), the mean valueswere 1,363 ml and 1,287 ml with respectivestandard errors of 6.3 ml and 5.8 ml. Signific~cetests comparing the FVC’S and FEV1.0’s bothfell in the region of rejection, with z values of5.89 and 2.18. It should be noted that the dif-ference between the mean FVC’S was almost 0.2liter, while that between the mean FEV1.0 ‘S Was

nearer 0.1 liter. The greater difference in FVC’sthan FEVI o‘s suggests that the HES tri~s werenearer termination by the time 1 second hadelapsed.

Of primary concern in explaining the largedifferences between the HES and SLC spirom-etry means is the question of difference in test-ing milieu. Although the HES technicians weregenerally very competent and responsible, espe-cially in body measurements and X-ray tech-nique (by initial qualification they were all cer-tified X-ray technicians), they were not highlytrained spirometrists. In HES Cycle II, spirom-etry had not yet been given the importance itachieved in later HES work. Training and experi-ence of technicians, sophistication and qualityof equipment, and guidance-motivation monitor-ing were all at a much lower level than in SLC.Added to this, it seems likely that more than7,000” examinations dulled the technicians’enthusiasm to some degree. In addition, the2%-hour testing period (after a trip of from 15to 45 minutes to the trailers) and the confusingand awesome array of examinations could bore,tire, and overwhelm the young child. Also, itbecame apparent, that, in spite of efforts to putthe children at ease, they were sometimes in-timidated by the new environment and the un-familiar examinations. These effects were espe-cially pronounced in the younger chMren.

The SLC children, on the other hand, weretaken from their classes in school to the nearbyexamination unit, so were in more familiar sur-roundings. The children went in a school groupso they had the enthusiasm and support of their

20

peers. In fact, a good deal of competition devel-oped among them, since the children entered theexamination room in pairs, one to take the testand one to observe. They were spurred on byclearly excited, friendly, and extraordinarilyknowledgeable and skilled technicians and amotivation mechanism called the “MotivationalAssisted Spirometry System (MASS),” whichwas attached to the spirometer itself.6 Thespirometer used for the SLC study, althoughachieving the same end as that used in the HES,was by design more accurate and sensitive. Par-ticularly, it minimized the initial mechanical in-ertia which tended to dktort the early part ofthe curve, an important consideration since thecurve tends to be rather short and of less me-chanical force for 6- and 7-year-olds. These ad-vantages and those mentioned earlier created anideal testing situation.

In summary, it can be seen that the children’in the Salt Lake City sample performed signifi-cantly better than those in the HES sample,both in terms of rate and volume-time-expiration. The comparison can be formulatedin two ways: (1) the HES data versus the SaltLake City “best of five trials” data (this isassumed to be an ideal condition because it per-mits each child to reach the maximum of hislearning effect) and (2) the HES data versus theSalt Lake City “best of two trials” data (a moredirect comparison because similar amounts oflearning occur between the samples).

The first comparison demonstrates that thepercentage of HES children having FV@’s lessthan 1 second was almost eight times as great asthat of Salt Lake City chiIdren having FV~’sless than 1 second (39.7 percent versus 5.1 per-cent). Also, the mean Salt Lake City FVC(1,617 ml) was almost 19 percent greater thanthe mean HES FVC (1,363 ml), and the meanSalt Lake City FEV1 -0 (1,441 ml) was almost12 percent greater than the mean HES FEV1.0(1,278 ml). Although the mean standing heightsof the samples differed by about 0.6 inch, bythe HES regression of FVC on height it is esti-mated that this difference accounts for less than40 ml of the net FVC difference.

Using only two of the five Salt Lake Citytrials for the comparison reduced the differencessomewhat. The percentage of HES subjects hav-ing FV~’s iess than 1 second (39.7 percent)

was a little more than 21/2 times as great as thepercentage of Salt Lake City subjects havingFVC+.’s less than 1 second (15.1 percent). Themean Salt Lake City FVC was more than 13percent greater than the mean HES FVC (1,546ml versus 1,363 ml), and the mean Salt LakeCity FEV1. o was more than 8 percent greaterthan the mean HES FEV1. O (1,395 ml versus1,278 ml).

There seems to be little doubt, having foundthe samples quite similar in terms of relevantindependent variables, that the spirometric dif-ferences are due almost entirely to differences intesting milieus. Perhaps the most importantsingle factor is the greater opportunity availableto the Salt Lake City subjects to achieve maxi-mum learning, as demonstrated by the meas-urable and consistent differences between the“best of two trials” data and the “best of fivetrials” data just offered. This effect is more dis-tinct in boys whose mean FVC increased from1,543 ml to 1,649 mI with the three additionaltrials, than it is in girls whose mean FVC in-creased only from 1,549 ml to 1,594 ml, sug-gesting that girls in this age range either learnfaster or fatigue earlier.

The Salt Lake City spirometry data collec-tion was methodologically and mechanicallysuperior to the HES spirometric operation inalmost all respects: the equipment had less in-ertia and was more sensitive and accurate, thequality of encouragement, motivation and in-struction was distinctly better, and the subjectshad ample opportunity to achieve maximumlearning. These factors all contributed to bringingthe SaIt Lake City children to a closer approxi-mation of their true maximal effort and henceto a more accurate estimate of the physiologicparameter of interest, forced expiatory volume.

Annapolis Substudy

The methodology of the Salt Lake City sub-study differed from that of HIM Cycle II in onerespect not yet evaluated. The HES subjects allinhaled through the spirometer hose after thebell was lifted to draw room air into the spirom-eter (called a “closed” system), while the SLCsubjects all inhaled ambient room air (caJled an“open” system), which is the more commonlyused technique. It was conjectured that the

21

closed system might be inhibitory (a respiratoryclaustrophobia), because many children did notinhale maximally (and reach TLC) when theycould not see the source of the inhaled gas. Totest this hypothesis, a final substudy was per-formed on 22 six- and seven-year-old boys andgirls enrolled in an Annapolis, Maryland, privateschool.

The children were first introduced to thesubject of spirometry via a short classroom dis-cussion of the objectives and a demonstration ofthe proper technique of the test. Pairs of chil-dren were then brought into the testing room,and the procedure was reviewed. Each child per-formed two complete sets of FES’S, one withthe open system and one with the closed. Thespirometer used in this study was the same oneused for almost half of the subiects in HESCycle II, 1963-65. (After it was cleaned and re-calibrated, its present performance was found tobe identical to its Cycle II performance.) Half ofthe children did the open system first, and theother half did the closed system fh-st. In all casesthe children were allowed practice trials untilDr. Palmer, acting as the technician, felt thatthey understood the maneuver, and then up tofour trials were performed. Measurements (inmillimeters), from the tracings thus recordedand information on age and stature were the rawdata of this study.

The mean age of the children was 6.71 years(many of the children were completing their sec-ond year of school). Their average stature was124.2 cm, while for HES Cycle II the averagestature for 6.7-y ear-olds was 119.4 cm. Themean FVC of all best trials on the open systemwas 1,528 ml, while the mean FVC of zdl besttrials on the closed system was 1,541 ml. Ofcourse, this minuscule difference is not signifi-cant at the Q = 0.05 level.

Males did slightly (but not significantly)better on the open than on the closed system,with mean FVC’S of 1,643 ml and 1,637 ml. Forfemales, the relationship was reversed, with themean FVC for the open system (1,391 ml) in-significantly less than that of the closed system(1,428 ml).

The relationship of FVC and stature was verystrong, P < .01, when the best trial by either sys-tem for each child was used. A l-cm stature dif-ference accounted for an FVC difference ofabout 35 ml. This value compares closely withthat noted for HES of about 30-40 ml/cm.

A final observation concerns the differencebetween the mean male and female FVC values.Using the best observed trial for each sex (1,643ml and 1,428 ml) a difference of 215 ml wasobtained. However, there was also a 3.7-cm dif-ference in mean statures (126.0 cm for malesversus 122.3 cm for females), and applying theaforementioned 35 ml/cm adjustment factor re-duces the mean FVC difference from 215 ml toabout 85 ml. This value falls between the 55-lnldifference estimated from the SLC study andthe 150-ml difference estimated from the HESdata.

This study provides the strongest possibledemonstration that the difference in resultsfrom an open or closed system is totally negligi-ble in children given an optimum testing envi-

ronment and some preinstruction. Also, the sim-ilarity of mean FVC values between this sub-study and the SLC substudy and the disparitybetween them and the mean FVC values of theHES provide further support for the hypothesisthat the testing milieu is one of the most signifi-cant factors affecting FES performance in chil-dren (probably even greater than sophisticatedelectronic equipment).

000

22

REFERENCES

1National Center for Health Statistics: Forced vitalcapacity of children 6-11 years, United States. Vital andHealth Statistics. Series 11, No. 164. To be published.

2Hutchinson, J.: On the capacity of the lungs and onrespiratory functions: With a view of establishing aprecise and easy method of detecting disease by thespirometer. Trans. Med. Chir. Sot. London 29: 137-252.1846.

3Tiffeneau, R., and Pinelli: Am circuhmt et air captifclans l’exploration de la fonction ventilatrice pulmonaire.Park Med. 133:624-628, 1947.

4Dayman, H.: The normal expiatory spirogramtechnique, in Current Research in Chronic ObstructiveLung Disease. 10th Aspen Emphysema Conference,1967. pp. 443-447.

5Discher, D. P., Massey, F. J., and Hallet, W. Y.:Quality evaluation and control methods in computerassisted screening. Arch. Environ. Health 19: 323, 1969.

6Discher, D. P., and Palmer, A.: Development of anew motivational spirometer-rationale for hardware andsoftware. J. Occup. Med. 14: 179, Sept. 1972.

7Sobol, C. J.: The mid-maximum flow rate, are-examination. Amer. Rev. Resp. Dis. 92:915, 1965.

‘Hyatt, R. E., Schildre, D. P., and Fry, D. L.:Relationship between maximum expiatory flow rateand degree of lung inflation. J. App. Physiol. 12: 331,1958.

‘Palmer, A. et al.: Spirometry using motivationaltechniques. ]. Chronic Dis. 24:643,1971.

10Brough, F. K., Schmidt, C. D., and Dickman, M.:Effect of two instructional procedures on the

performance of the spirometry test in children fivethrough seven years of age. Amer. Rev. Resp. Dir. 106:604-606, 1972.

11 Gaensler, E. A., and Wright, G. W.: Evaluation ofrespiratory impairment. Arch. Environ. Health 12: 146,1966.

12American College of Chest Physicians: Recom-mendations of the Section on Pulmonary Function Test-ing Committee on Pulmonary Physiology. Dis. Chest 43:214-219, Feb. 1963.

13 Fairbaim, A. S.: A comparison of spirometric andpeak expiatory flow measurements in men with andwithout bronchitis. Thorax 17: 118, 1962.

14Afschrift, J. et al.: hkximal expiatory andinspiratory flows in patients with chronic obstructivepulmonary disease. Amer. Rev. Resp. Dis. 100:147-152,1969.

15Polgar, G., and Promadhat, V.: Pulmonary FunctionTesting in Children: Techniques and Standards.Philadelphia. W. B. Saunders Co., 1971.

16 National Center for Health Statistics: NCHS growthcurves for children, birth- 18 years. Vital and HealthStat&tics. Series 1 l-No. 165. DHEW Pub. No. (HRA)77-1650, Health Resources Administration, Washington.U.S. Government Printing Office, Sept. 1977.

17 National Center for Health Statistics: Height andweight of children: Socioeconomic status, United States.Vital and Health Statistics. Series 11-No. 119. DHEWPub. No. (HShi) 73-1601. Health Services and MentalHealth Administration. Washington. U.S. GovernmentPrinting Office, Oct. 1972.

23

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

LIST OF DETAILED

FVC of children 6-11 years of age, by quality group, age, rata, and sex:

TABLES

Sample siza, mean, and standard daviation, HealthExamination Survay Cycle 11, 1963-65, unedited data .. ... ... .. .. .... ..... ....... .... ... ....... ..... ............. ..... .... ..... ...... ........... .... ................

FEV1 of children 6-11 years of age, by quality group, age, race, and sex: Sample siza, mean, and standard deviation, HealthExamination Survey Cycle 11, 1963455, unedited data ..... .... .. .... ..... ............................ ... ....... ..... ... ........ ..... .... ...........................

‘EF25.75% of childran 6-11 years of aga, by quality group, age, rata, and sex: Sampla siza, mean, and standard deviation,Health Examination Suwey Cycle 11, 1963-65, unedited data .. ...... ............ .. .... .... ...... .. ... ...... ..... ..... ..... ............................. .... ....

Number and percent of childran 6-11 years of age, by education Ieval of first-listed parent, quality group, and age ofchildren: Haalth Examination Survey Cycle 11, 1963-66, unedited data . .... .... ...... .. .... .. .. .............. .... .... .. .... .... .. .. ... ..... .... ...... .....

Numbar and parcent of children 6-11 years of age, by animal family income, quality group, and age of children: HealthExamination Survay Cycla 11, 1963-65, uneditad data ...... ..... .... ............ ..... .... ..... ....................... .... .. .... ..... ....... ..... .... ...... ... .. .....

IQ of children 6-11 years of age, by annual family income, quality group, and age of children: Haalth Examination SuwayCycle II, 1963-65, unedited data ........... ...... .... .. .... ...... .... .. .... ..... ........................... ... .. ..... ..... ..... ... .... .... ...... .... ........................ ...

Number and percant of children 6-11 years of aga, by geographic ragion, quality group, and age: Health Examination SurveyCycle 11,1963-65 ......... ............ .... .... ...... ..... ................ ..... ....................... .. .. .... .. .... .... .. .. ... .... ... .... ....... ............................. ...........

Height in centimeters of children 6-11 yeara of aga, by quality group, age, rata, and sex: Sample size, mean, and standarddeviation, Health Examination Suwey Cycla 11,1963-65 ....... ..... ....... .... .... .. ...... .... .... ...... ................ ...... ............ .. .. .... .. ..... ..... ....

Sitting height in centimeter of children 6-11 years of age, by qualitY group. a9e, race, and sex: SamPle size, mean zstandarddeviation, Haalth Examination Survey Cycle II, 1963-65 ...... ...... ........... .... ....................... .... .. ........ .. .... ...... .... .... .. ..... ................

FEV1 of children 6-11 years of age, by age, sex, and race: Sample size, weighted sample size, standard deviation, standarderror of the mean, mean, and selactad percantilas, Health Examination Survey Cycle 11,1963.65 .. ....... ..... .................. ..... .. .. .....

FEF 25.75% of children 6-11 years of age, by age, sex, and race: Sample siza, weighted sample size, standard deviation,standard error of the mean, mean, and salactad percentiles, Health Examination Survay Cycla 11,1963%5 .... ..... ..... ...... .. .... ....

25

27

29

31

32

34

35

36

38

40

42

24

Table 1. FVC of children 6-11 years of age, by quality group, age, race, and sex: %mple size, mean, and standard deviation,Health Examination Suwey Cycle 11,1963-S5, unedited data

Quality group

IB IGIE IIAge, race, and sex

Xlsc)n n n n

Total Milliliters Milliliters Milliliters

12531,4201,6181,8272,0132~90

1#26B1,4461,6531,8472,0502/332

1,1461,2621,4281,7061,7801~B8

1,2991,4S61,6911~oo2,0892>85

1#2031,3541J5421,74019282,186

24726230335a377445

247259

1,3091,5181,6691,8462,0442287

1,3081,5381,6941,8772,0702,335

1,3081,3581,5041,6171,8632.042

1,3801,5821,75s19302,1202,357

1J?341,4331,5641,7641#8662~oo

245 1,2481,4151,8081,7981,8572,212

1,2701,4351,6421,8261,9872,259

1,1221,1551,4s51,50s1,65S1/810

1,3121 ,4s01,6621~382,061228

1,1691,3561,5341,7551J3782,122

25428527833641244s

1,2821,4391,6331,7552,0262,197

1,2861,4281,5661,7882,0412,195

1,2151,5s41,3741,1541,6862,210

1,3631,4281,6561 ,ss41,8822,261

1,1551,4481,4481,6622,0832,155

2712372813573s6

6 yeara ....... .. .. ...... ................ ..... .... ...........7 years ........... ..... ................. ..... .... ....... ....8 years . .... .... ...... .................. .... .. ... ....... ... .9 yaars ..... .... .. ...... ................ .... .. .... ..... .. .. .10 years .... ... .. .... .. .. .................... .. .. ..... .....11 years .... .. .. .. .. ....... ..... ............ .... .. .... .....

510646606

184219303279308345

1711952632462692s8

232440333957

10U125147136

94121

98114110111

202922191925

192718181721

124124

1213

98

1010

8161311

915

306297343381434

242303294345

5s0320

White

6 yeara ........... ..... ...... ..... ................ ...... ....7 yeara ..... ............ ...... .... .... ................. .....8 years ... .... ... ....... .... ...... .... .. . ... ............ ... .9 years ..... .. .............. ...... ...... ..... ........... ....10 yeara ... ..... ............ ....... .... .... .............. ..11 years ... ...... ........... ..... .... .. ..... ........... ....

44s554512513502496

649294857870

265322308315

so112

77104?00

290272328392431

21224028s281508451

235

242287335392344

54106

434174

186262356363

35336s437

218225272365

374422

27328826s226

96

Nearo

6 yea= ...... ... .. ........... ............. .. . ...... .........7 years ..... . ... ... ... ....... .... .. ....... ... .... ...........8 years ..... .. .. ................. ...... ..... .. .......... ....9 years ..... ..... .... .. ........... .... .. ... ....... ..........10 years ..... .... ...... .......... .... .. .... ...... ..........11 years ... ... .... ... ............ ........... ... ... ... ......

149

21101015

525757584757

426441556354

351 391387

255254280376378436

228254298315357433

416

257330298343377426

207

Male

6 years ..... ...... .. ..... .......... ..... .... .. ... ..... .. ....7 years ....... .... .... .. ................ .... . ..... ...... ....8 yea~ . ...... .. ..... ... . .. ............. .... .... .. .. ........9 years ....... ... ...... .. ... ................. ... .. .... ......10 years ....... .. .......... ............... ....... ...... ....11 years ..... ... ....... ................. ........ .. ... ......

2s4273335422535

257285270335390314

156285

245324287283281271

191

8494

166141152

188

319223182337379380

Female

6 yeara ..... .... ... .... . ... ....... ........... ... .. ..... .... .7 yeara ........... ... .. . ... ....... .... ............ ..........8 yeara . .... ............ .... ...... .... .. ................ ... .9 years ..... .... .. ...... ...... ... ..... ...... ............ ....10 yeare ..... ... ....... .... ...... .... .. .... .. .... ..........11 years .... .... ............ ..... ..... ..... .... ............

250271324371428155

tandard deviation.NOTE: n = sample size, ~ = mean, SD

25

Table 1. FVC of children 6-11 years of age, by quality group, age, race, and sex: Sampla size, mean, and standard deviation,Health Examination Survey Cycle 11, 1963-65, unedited data–Con.

Age, race, and sex

White male

6 years .. .... .. .. .... .. ... ..................................7 years ..... ...... ...................... ...... .... .... ......8 years ...... ................ ..... ..... .... ... ........... ...9 years ................ ... ....... ............ .... .......... .10 years ..... .... .. .. .. .... .. ... . .... ...... ...... ... ... ....11 years .......... .. ... .......... ......... ...... ...........

White female

6 years .......................... ..... .. ... .... .... ... .. ....7 years ............ .... ..... ..... .. ......... .... ....... .....8 years .. ..... ... .... .. ...... .... ...... .... .. .......... .....9 years . .... .. .. .... ... ........... ..... ..... ................10 years .. ...... . ..... . .......... ....... ...................11 years .... ... .. ..... ..... ...... ...... ....................

Negro male

6 years .............. .. .... .. .... ...... .. .... ..... ..... .... .7 years ..... .. .... .......... ........ ............. ..... .. ....8 years ..... ...... .... ................. .....................9 years .... ....... ..... .... ... ..............................10 years ........ .. ..... ........................... ... ... ...11 years .. ..... ....... ............ .... ...... ..... ..... .....

Negro female

6 yeare ...... ........... ..... .... ...... ..... .. ..... .........7 years ..... .......... ................ ................. ... ..8 years ..... .. .. .. ...................................... .. ..9 years .... ...... ............ ...... ........ .. .... ...... .....10 years ............... ... ...... ...... ..... ...... .... ......11 years ... ...... .. ... .... . ...... ....... ... ..... ... .... ....

n

227286270275256259

219266242238246237

383639403336

265655454534

3k SD

Milliliters

1,3191,5051,7171,8402,1372,438

1,2161,3641,5811,7411,8582,217

1,1801,3341,5131,6761,8052,008

1,0961,2161,3701,7331,7611,867

258252285363365424

225252293310350423

202216269368349328

235220260345365444

Quality group

—n

—

85111131123137167

8684

132123132122

151416151924

81024182033

—

18

31.XMilliliters

1,3991,6011,7841,8612,1552,388

1,2201,4541,6041,7931,8822,247

1,2701,4341,5461,6731,8672,063

1,3821,2511,4751,5711,8602,028

256330298346372416

190243261323355415

246302206170315382

323246303260461444

—n

—

445446534245

365831515851

83

1165

12

66

10453

—

IC-IE

L.kMilliliters

1,3311,4951,6971,8722,0882,414

1,1961,3801,5611,7781,9142,123

1,2091,2171,5161,5401,8381,862

1,0071,1241,4501,4601,4782,103

237281277326392491

260289248326379317

208222207274636480

167263332352306301—

—n

—

1112

9898

815

910

813

11

12

14112

—

II

_I-kMilliliters

1,3981,4111,6561,8642,0372,272

1,1551,4421,4811,7122,0452,147

1,2151,622

1,5902,217

1,5451,3741,1642,2032,202

20026735836340716’1

31922920430[1401419

269

106

136

NOTE: n = sample size, ~ = mean, SD = standard deviation.

26

Table 2. FEV, of children 6-11 vears of age, by auality grow, age, race, and sex: Sample size, mean, and standard d~iaticm, Health

;arninat;on Sum-ey Cycle 11, 1963-65, unedited data

Quality group

Age, race, and sex lC-lE

Zlz

Milliliters

II—

n n n n

Total Milliliter Milliliter Milliliters

1,1881,3441,5131,6641,8382,062

1,1991,3651,5371,6981~662,080

1,1131 ~201,3801,5971,6851,662

1,2271,4001,5761,7331,9012,124

1,1461#2681,4471,6281,7761 ~84

1#2281,4231#5441,7131,8442,073

1,2341,4391,5661,7361,6632,110

1,1951,2871,4011,5441,7191 ,6S7

1,2791,4751,6211,7821,8802,103

1,1761,3531,4721,6451,8082,037

226275

1,1601,3511,4941,6361,8051,961

1,1731,3681,5081,65713261,884

1,0871,1381,4361,4221,6001,811

1,2021,4061,5421,6761,9031,958

1,1081,3001,4271,5631,7321~64

232262257327345

510646606588680566

446554512513502496

649294857870

265322308315289285

245324267263281271

194219303279308346

171195263246269289

232440333957

100125147138156191

9494

156141152155

6 years .... ........ .... ........... ..... ..... ....... .... ..7 years ..... .. .. ....... ........... ..... ... .. ...... .... .. .8 years ..... ..... .... .... ... ................. .... ...... ..9 years ...... .... .... .. ..... .... ....... ....... ... .. ..... .10 years ........ ....... ... .. .... ...... ............. .....11 years .. ..... .. .............. ...... ......... .. ... .... ..

238244272321344406

242243269320340

9412198

114110111

80112

77

202822791925

192718181721

124124

121398

1010

81613119

15

1,2161,3801,4411,5941,7701,886

1,2171,3661,4681,6181,7671,865

1,1921,5721,3241,1541,7962,010

1,2961,3751,4981,7201,6581,753

1,086I ,3641,4021,5021,6841,978

253211236281399444

260211253268414458

3850

355389

128242316291425541

348180164246350

307353389

White

223273259310350

2356 years ..... ....... .... ... .............. .. .. ...... ...... .7 years . ........... .... .... .. .. ... ............ .. ........ .8 years .......... ..... .. ... ... ..... ............... .... ...9 years ...... ..... .... .. .. .....b.. .... ............ .......10 years ........... ... . .... .... ... ... ............. ......11 years .... ... ..... ....... ..... ............... ..... .....

258254321324377

208225266321485446

227245242315342451

231

104100

96

149

21101015

525757594757

426441556354

402

Nemo

6 years ..... ....... ... .... .............. .... ......... ....7 years ...... ...... .. .. ..... ................. .... ...... ..8 years .......... ...... ........... ................ .... .. .9 years ............. .. ..... ....... .... ........ .... ..... ..10 years ........ .. ..... ... ........ .... ............ ......11 yaars .. .... .. ... ... ............... ... ......... ....... .

186211250312318378

250263283219360364

237302246284346361

202219268

Mala—

6 years ..... .. .... .... .. .... ............ .... .... ... ... .. .7 yeara ....... ... . ..... ..... .. ... ............. .. .. ...... .8 yeara ..... ....... .. .. ....... ... ................ ...... ..9 yaars ........... ..... ..... .... .. ................. ... .. .10 years .............. ...... ...... .. .................. ..11 years ... .... ........ .. ... .. ....... ... ............... ..

250237

336344380

215238268264332413

Female

6 years .. ... ..... .. ..... ... .................. ...... ... ...7 years ...... ... .... .. .... ...................... .... .... .8 years .......... ...... .. .. . ..... ...... ........... ..... ..9 years ............ .. ........ ... ...... ...... ............ .10 years ............ ...... . ..... ........ .. ..............11 yearn ... ...... ... ........................ ... .... .. .. ..

269265336332315

305355396

NOTE: n = sample size, ~ = mean, SD = standsrd deviation.

--”

27

Table 2. FEV1 of children 6-11 years of age, by quality grow, age, race, and sex: Sample size, mean, and standard deviation, Health

Examination Survey Cycle 11, 1963-65, unedited data–Con.

Age, race, and sex

White male

6 years ........... ..... .... ..... .. .. .. .... ...... ........ .7 years . ...... .... .......... .... ...... ..... ... ...... .. ...8 years ..... .......... ........ ........ .. .... .. ...........9 years ..... ..... ...... .... ...... ..... ..... ..............10 years .... .... .... ... ... ...... .... ....................11 years ..... .. ....... ................................. .

White female

6 years ........... .. .... ..... .... ....... .... ..... .. ......7 years ........... .......... ............ .... .... ... .... ..8 years ..... ...... .. .... ...... .... .... ........ .... .. .. ...9 years ..... ............ .. .. .... ...... ...... ....... ... ...10 years .. ....... ... ...... ....... .. ... ...... .... ........11 years ... .... ... .... ..... ..................... ........

Negro male

6 years ...... ... ... ......................... ... .. ........7 years .... .............. ..... ..... .... .. .. .. .... .. .... ..8 years .... .. ............... .. .... .... ............ ..... ..9 years ........... .... .. ... ....... ...... ...... ... ..... ...10 years ......... ..... ........... .... .. .... .... ........ .11 years .... .... ........... ..... .... .. .... .. ..... .... ...

Nagro female

6 years .. .. .. .... .. ..... ... ............................ ..7 years ..... ..... ...... ....................... .... ...... .8 years ...... ....... .. ........................ .... ..... ..9 years ..... .. ........................ .. .. ... ... ........ .10 years .............. .. ................ .... ..... ... .. ..11 years ............... .... ...... ..... .... ....... .... ...

n—

227286270275256259

219268242238246237

383639403336

265655454534

&k SD

Milliliters

1,2411,4161,5941,7601,9302,159

1,1551,3101,4741,6281,7992,014

1,1471,2701,4491,5521,6811,871

1,0641,1891,3311,6361,6541,853

259237256333338382

216238269280329411

172196254302311357

198216238318326403

Quality group

n

85111131123137167

8684

132123132122

151416151924

810“24182033

Y~ SD

Milliliters

1,3031,4921,6381,8001,9122,133

1,1661,3681,4941,6711,8122,080

1,1451#3371,4791,6351,6561,688

1,2801,2171,3491,4681,7791 )379

233302243301346377

191210255307348391

221266231175277352

287255306226406377—

n

445446534245

365831515851

83

1165

12

66

10453

IC-IE

=

Milliliters

1,2061,4211,5611,6921,9242,008

1,1331,3191,4311,6201,7541,963

1,1811,1731,4581,5381,7261.770

9621,1211,4161,2491,4731,976

236243241318287438

231284256324327316

182147238275631469

185266305341304361

n—

1112

9898

815

910

813

11

12

14112

k:x SD

Milliliters

1,3051,3561,4981,7201,6711,729

1,0961,3731,4371,5371,8751,948

1,1921,599

1#6451,850

1,5451,4241,1542,0472,169

130243316291449572

348191187229369373

564

50

184

NOTE; n = sample size, ~ = mean, SD = standard deviation.

28

Table 3. FEF25.75% of children 6-11 years of age, byquality group, aga, race, and sex: Semplesize, mean, and standard deviation,Health Examination Survey Cycle II, 1963-65, unedited data

Age, race, and sex

Total

6 yeara ..... ............ .... .. .... ...... .. .. .... ........7 years ..... .... .. ...... .... .... .. .... .. .... ..... .......8 years ...... .. .. .... ........ .......... ..... .... ....... .9 years ..... . .... ..... ... ............... .... ..... ..... ..10 years .... ..... . .... ..... ................ ............11 years ........ ...... . .... .. .... ................ .. ... .

White

6 yeara .. .. ...... ...... ................. .... . ..... ..... .7 years ...... .... .... .. ..... .................. ... .......8 yea= ....... .. .. ..... ........... .. .. ............ .... ..9 years ............ .. .. ... ......... .... .... ........ .....10 years ....... ....... ..... ... .. ...... .... .. .......... .11 years ... .. .. ............. .... ....... .... .. .... ..... .

Negro

6 yeara ........... .... . ... .. ...... ..... ............... ..7 years ..... ........ ... ..... ......... ... .. ............ ..8 years ..... . .. ... ...... .. .... .... .... .. .... .. ........ ..9 yaars ..... .. ... ....... .. ... ........... ..... ... ........10 years ........ ................. ... .... .. ....... ..... .11 years ... .. .. .. .... .................. .... .. .. .... ....

Male

6 years ... ... ... ........ .......... ...... ..... .... .......7 years ...... .... ............. ... ...... ...... ... ........8 years ...... ..... ..... ........... .... ... ... .. .. ...... ..9 years .... .. .... . ... .. ..................... ....... .... .10 years ... ...... .... .. .... ..... ........... .. ......... .11 years ......... ... .... ... ..... ..................... ..

Female

6 years .. ... ..... ... .. . ..... ........... ........... ......7 years . .... .... .. .. .. .. .... .................. .. .. ......8 yea= ..... .. .... .. .... ..... ..................... .... ..9 years .......... .. ... . .... .......... ...... .............10 years .. ............. .. ... ..... . .... .... .. .. . ........11years ... .. .... .......... .. ... ....... .... . ..... ......

n

510646606588580566

446554512513502496

649294857870

265322309315289285

245324287283281271

Y~ SD

Milliliters

1,7681/8732,1222,2632,4132,651

1,7551,9662,1052J592,4152,662

1,8662,0032,2152#2882,4002,574

1,7982,0022,16722452,4282,659

1,7381,9452,0752,2832,3972,642

497523557628665762

501517542627657752

461559628637717830

495537525623635750

488508587635694775

NOTE: n = sample size, ~ = mean, SD = standard deviation

Quality group

—n

—

194219303279308346

171195263246269289

232440333957

100125147138156791

9494

156141152155

*~ SD

Milliliters

1,7421,9172,0682,2722,3352,579

1,7561,9252,07422652,3252,608

1,6391,8522,03123202,4002,428

1,7821,9872,1702,2872,3132,540

1,7001,8251,9722,2572,3572,627

530507577666

662

534

537652688688

502517788770700635

614526593532734658

424466546776641706

n

94121

98114110111

80112

7710410096

149

21101015

525757594757

426441556354

IC-IE

-

Milliliters

1,7462,0122,0652,1592,4322,508

1,7192,0142,0512,1392,4142,503

1,6861,9922,1142,3682,6042543

1,8362,1102,1232,1162,5152,457

1,63419261#8842#2042,3702,562

515517536640589746

510520547630566740

535488503739682813

504508537601512776

512613531662653716

—n

—

202822191925

192718181721

124124

121398

1010

8161311

915

II

*Milliliters

1,7572,0082,0752,1672,2072,464

1,7531,9222,0482,16922232,400

13.423,1822,1962,1372.0702,797

1,8!592,0181,8872,4232,0362,284

1,6042,0022,2051,8812,3972,577

554557470650711817

568467498668741755

252333

5361,167

367543481778856

1,010

758586432495466672

29

Table 3. FEF25.75% of children 6-11Healtl

Age, race, and sex

White male

6 years ........... ... .. .... .. .... .... ... ........ ... .... .7 years ...... .... ...... ..... ...... ..... .. .. .. .... .......8 years ..... .... .. .... ..... ..... ........................9 years ..... ................................. ....... .. ..10 years .................... ..... ..... ...... .......... .11 years ... ........... ...... .... ...... .. ... . ...... .... .

White female

6 years ........... ...... .... ...... ..... ..... .... .... ....7 years ........... ..... .. .. ...... . ........... ... .. .... ..8 years ..... .. .. .. .. .. .. ...... .... .... ... .. ........ .... .9 years ..... .... ...... .. .... ...... .... ... ... .... ........10 years ......... ...... ... . .... ........................11 years ........ .... ........................ .... ...... .

Negro male

6 years ..... .. ...... .. . .. ... ...... ..... .... .............7 years . .. .. .. .... .... ..... .............................8 years ...... .... .................. .......... ...... .... .9 years ................. .... .. .. .. ...... ........ .. .... ..10 years ..... ........ ...... ...... .... ...... ...... .... ..11 years ... .. ...... .... ... .................. ..... .... ..

Negro female

6 years .................. ... ...... .... ....... ....... ....7 years ........ ........ ..... ...... ... .. .... ...... .. .... .8 years .. .. .... .. .... .. ..... ........... ...... ...... .... .9 years ..... .. .. .. .. ......... ..... .. ..... .. . ............10 years ... .. .. ....... .... .............................11 years ....... .. .... ........................ ......... .

aars of age, by quality group, age, rata, and sex: Sample size, mean, and standard deviation,Examination Survev Cvcle II. 1963-65. unedited data–Con.

Quality group

n

227286270275256259

219268242238246237

383639403336

265655454534

YF SD

Milliliters

1,7762,0062,1612Z662,4372,671

1,73319282,0432,2632,3922,652

1,928

1,9732,2082,1722,3622,576

1,7812,0222,2202,3932,4272/672

502530517631620742

500501563624694763

430

601578564745808

500535666686703864

n

85111131123137167

8684

132123132122

151416151924

81024182033

Y~ SD

Milliliters

1,8231,9962,1562,2742,3262,556

1,6901,83213922,2562,3242,682

1,5501,9132,2642,3932,2172,435

1,8071,7661,8622J562,5742,424

623529548547737653

422461515744636730

519508

381727704

454542696994642591—

—n

445446534245

365831515651

83

1165

12

66

10453

IC4E

=

Milliliters

1,7872,1052,1322,0922,5042,455

1,6361,9281,9322,1872,3492,545

2,1032,1952,0852J362,6012,466

1,6181,8912,1472,4162,6072,852

498518546624435774

521512536638640713

466322521270

1,033820

502565509

1,230

627866

—n—

1112

98

:

815

910

813

11

12

14112

—

*SD

Milliliters

1,8611,9361,8872,4232,0752,356

1,6041,9122,2081,9662,3902,427

1,8423,004

1,6812,042

3,3612,1962,1372,4493,552

385476481778898

1,084

758476488519521511

897

333

999

NOTE: n = sample size, X = mean, SD = standard deviation.

30

Table 4. Numtxr and percent Of children 6.11 yearn Of age, by ~ucati~n IeWI Of fimt.lified parent, quality group, and age of children: Health Examination 6urvey Cycle 11,

1963.65, unedited data

Education of first-listed parent

Less than5 years

17yearsor more

C2uallty groupand age 5-7 vears 8veam 9-11 years 12 years 13-15 years 16 years Unknown

Num-ber

.Per-cent

Num-ber

223633484342

12-1

127

1318

643

14811

22

213114131311

963214

Per- Num.Ix

Per. Num-ber

Per- Per- Num.bw

Per- Num.ber

Per. Per-cent

Per.centcent ber ber ber—

4.35.6

z7.47.4

6.73.24.02.54.25.2

6.43.33.1

12.37.39.9

10.510.5

8.516.68.289

10.88.8

!0.0I5.49.77.74.39.0—

y

6 years ... .. .... .. ...... .. ..7 wars ... .. .... .. ...... .. ..8 years ..... ... .... ......9years,..,,,,..,.,..,..,,.,10 years . .. .... . . . ..11 years.,,.,,.,,,,,,,,..,..

~

6 vears .... .... .. . .. .....7 years .... ...... ..... ... ...8 years .... .... .... .. . ..9 years . .. ...... ...... .. ....70 yeart .... .... .. ... ......11 years.,.,...,..,..,..,..,

IC-IE—

6 years .. . . . . . . . . . . . . .. . . .7 years .. . . . . . . . . . . . .. . . . . .8 years .... .... .. ...... .. .9 vears ...... ... .. ... ... ... .10 years .. ....... ... .....11 years.,.,.,...,..,..,...

~

6 years ...... ..... .. .. ....7 years .... ..... ... ... .. ...8 years .... ..... ...... . ....9 years ... ...... ...... ..... .10 years ..... .. ...... .. .. .11 years... ... ... .. ... .... ..

y

6 years . .. ... ... ........ ....7 veam . .. ...... ........ .. .8 years .. . . . . . . . .. . . . . .. . . .9 years . . .. .. . ....... ... ..10 years ... . .... .. .. .....11 years.., ....... ... ......

45EaSa656157

131125172635

:10

510

6

2

22

212212231214

236333

—

8.89.0

11.210910.510.1

6.75.08.36.18.4

10.1

6,46.6

10.24.49.15.4

9.1

10.5a.0

8.511.8

7.015.810.011.4

4.47.7

19.410.713.014.3

53w67696877

162227273738

71110

81419

131247

281723221416

572

31

10.49.3

11.111.511.913.6

8210.0

899.7

12.011.0

;::10.2

7.012.717.1

6.010.34.5

10.521.126.0

11.39.1

13.515.111.713.0

11.1179

6.5

13.04.6

112140134110101110

3341

:6471

232123271819

314

3437

534928272225

1311

611

47

22.021.722.118.477.419.4

17.018.722.122.220.820.5

24.517.423.523.716.417.1

15.046.313.621.115.628.0

21.426.216.418.516.320.3

26.928.219.438.317.433.3

16720615S166185160

:;10510010596

325151343228

108

10

;6

663547403832

101110

754

32.731.927.931.128.431.8

36.637.034.735,834.128.3

34.042.131.629.829.125.2

50.027.645.536.815.824,0

27.418.727.527.431.726.0

22.228.232.325,021.719.0

396151385130

172426212326

81056

129

222121

1915157

115

4

131

7.69.48.46.48.65.3

8.811.08.67,57.58.1

8.58.35.15.3

1098.1

10.06.99.15.3

10,54.0

H8.84.89.24.1

8.9

3.20.743

395736464637

m2125241933

97797

11

2111

1

189

1675

14

1141

7.68.65.98.07.96.5

10.39.68.38.66.29.5

9.65.87.17.96.49.9

10.03.44.55.3

4.0

7.34.89.44.84.2

11.4

3.23.6

17.44.8

262138243532

101113202122

28

:76

2

2231

134

10454

212121

5.13.36.34,06.05.7

5.25.04.3726.86.4

2.17.48.27.86.45.4

0.0

9.10.55.64.0

5.22.15.82.74.23.3

4.4

::3.68.74s

77

1010

91

1131

3

1

1222

11

7563

2

1.41.11.71.71.60,2

0.50.51.00,4

0.9

1.1

1.01.81.81.8

3.44.5

2.62.73.52.1

1.6

Deck 56 only

6 years .. ..... ........ .... .7 Veam ..... .. .... .. .. ..... .8 years ..... . .... .. . ... ..9 years .... .... .. .... .. ....10years . ... ...... ..... ... .11 years..., . .. .... ... ...

31

Table 5. Number and percent of children 6-11 years of age, by annual family income, quality group, and age of children: Health

Examination Survey Cycle 11,1963-65, unadited data

Quality group and age

6 years .. ..... .... ....... .................... ..... .... ....... ...... .... .. ...7 years . ...... .. .. ... ................... .... .. ..... ..... ... ....... ..... .. .. .8 years ................. ...... ... ..... .. ...... ..... .... ..... .. .... .... ......9 years ............ .... ...... ...... .... .. ..... ... ....... ......... ...........10 years .. .. .... .. .. .. ...... .... .... .. ...... .... ...................... .....11 years ... .. ... ....... ...... .............................. ...... .. .. ..... ..

6 years ........ .. .. .... . ..... ...... ... ....... .... ...... .....................7 years ..... .... .. ..... . .......... .. ... .. ..................... ..... .... .....8 years ... .. .. .... ..... .................................. .... ..... ...... .. ..9 years .... ...... .. .... .......... ....................... ... ...... .. .... .. ...10 years .. .. .... .. ................ ...... .... ... ...... .. .... . ...... ... . ... ..11 years .. ... .... .. .... .. ... ... .... ...................................... ..

IC-IE

6 years .. ...... .. .. ..... .... ..... ........................ ... ..... ...... .. ...7 years ...... .. .. ............................. .... .. ... .. ..... .... .. .. ......8 years ..... ........... ...... ..... ... ... .... .. ..... ...... ......... ..... .....9 years ............ ..... .............. ... .. . ..... ....... ... ....... ..........10 years . .. .. .. .. .. .... .. .......... ........................ .......... .. .. ..11 years .. .... .. .... .. .. .. .... .. .... .. .... .. .. .. .. .. .... ................ .. ..

6 years ........... ..... ..... .... ......... ... ... .. ........ .... ..... ..... .....7 years ............. ... ........... ..... ........... .. ... .....................6 yearn ..... .. .. ... ... ...... .. ... ....... ... ................. .. .... ...... ....9 years ..... . .... ... ... .. ........ ....................... .. .. ...... ... ... ....10 years ........ .................................... .. ...... .. .... .... .... .

11 years ... ......... ....... ..... .... ...... .... ............ .... ....... .. .....

JIJ

6 yaars ... .. .. .... ..... ............... ............ ...... ..... .... ...... ... ..7 years ....... ... ...... ... .............. ...... .... ...... .... ...... .... .. ....8 years .. ..... .. ................. ....... .... .. ..... .... .. ... ..... . .... ......9 years ... .............. .... ........ .... ..... ... .......... .. ...... .... ......10 Years .......... .... ...... .... ................. ..... ................. ....11 years .. ...... ............ .... .. ....... ..................... .. ..... ... .. ..

Deck 56 only

6 years ........... ........... ..... ..... . .... .. .... ...................... ....7 years ..... .... .... .. .. .. ........ ...... .... .................. .... .... ......8 years ....... ....... ... .. ................................. ....... .... . .....9 years ... ... ...r . .... ....................... ..... .......... ...... .... .. .. ..10 years .. .. ................ ..... ..... ........... ...... ... . ....... .... .....

11 years... ).. .. .... ....................................... .. ... ..... ......

Less than$500

Num-ber

763784

14

11

1121

43123

12

Per-:ent

1.40.90.51.21.40.7

0.51,3

0.30.3

1.10.82.00.9

1.61.60.61.42.5

2.25.1

$600-$899

Annual family income

Vum-ber

111713151012

3338

1217

3

3612

1

1

96892

521111

Per-cent

2.22.62.12.51.72.1

1.51.41.02.83.94.9

3.2

3.1

5.30.91.8

5.0

5.3

3.63.24.76.21.7

11.15.13.23.64.34.8

$1,000-$1,888

Num-ber

273831424227

81117122020

639388

13

13

2418121111

9

542213

Per-cent

5.35.96.17.07.24.8

4.15.05.64.36.55.8

6.42.59.22.67.37.2

5.010.3

5.315.8

9.79.67.07.59.27.3

11.110.3

6.57.14.3

14.3

$2,000-$2%9

Num-ber

314564484441

121616141922

7616

105

112311

3119161?1112

344131

Par-cant

6.17.0

10.68.07.67.2

6.27.35.35.06.26.4

7.45.01.05.39.14.5

5.03.49.1

15.85.34.0

12.510.29.47.59.29.8

6.710.312.9

3.613.0

4.8

$3,000-$3989

Num-ber

505054485248

161828221833

91211

79

12

134124

25241414

89

24722

Par-cent

9.87.78.98.09.08.7

8.28.29.67.85.89.5

::11.2

6.18.2

10.6

5.010.318.2

6.310.516.0

10.112.8

8.29.66.77.3

4.410.322.6

7.18.7

32

Tabla 5. Num&r and percent of children 6-11 years of age, by annual familv income. aualitv wouP, and am of childran: Health

Examination Survey Cycle 11, 1963-65, un&lited deta-”@n. ” -

Annual family incoma

$15,000or more

Unknownor refused

$7,000-$9,988

$10,000-$14s

$4,0C0$4,988

$5,000-$6s88

Quality group and age

Per-cant

24.525.222.923.221.225.6

26.324.222.419.421.820.8

25.526.423.528.120.018.8

30.034.522.726.326.316.0

17.324.622.819.820.032.5

!4.4?8.212.812.1?1.714.3—

Par- Per-cent

—Par-cent

Num- Num- Num Num- Numbar

Per-cent

Num- Per-centber ber ber bar

596260627066

282642404438

81610161515

343544

211422131213

513433

bar

18.421.220.320.122.617.5

20.622.423.426.822.119.7

22.327.321.418.419.125.2

25.013.813.6

5.35.3

28.0

17.717.118.721.220.014.6

11.1I 2.822.614.321.714.3

g

6 years . ............... .... ...... ...... ...... .....7 years ...... ..... ........... ......... . .... .......8 years ...... ... ...... .................. ... . ..... .9 year5 ...... ... ... .... .................. ... ......10 years ... ......... .. .................... .. .....11 yaars .... ... ............ .... ..................

~

6 years ...... ....... ... ............ ... ............7 years ......... .. ...... ................ ......... .8 years ....... .... .... .. ................ .... .. ....9 yaars ....... ... .... .. ...... .................... .10 years ......... ...... .... .. .. ..................11 years .................. ... .. ....... ... .........

IC-I E

6 years .. ... . .... ..... ................. ...... .....7 years ...... ..... ... .. .................. ... ..... .8 years ............. .. . ... .. ..... ... .......... ....9 yaars ...... ..... ..... .... .. .... .................10 years .............. ..... .. ... . ..... ...........11 years .. .... ........ .......... ..................

Q

6 yfreK ....... .. ....... ..... .. .. .. ............ ... .7 years ...... ..... ..... ...... .... ............ .....8 years ....... .... .. .. .. .. ........ .... ............9 years ...... .. .. ........... ..... .. ... ....... .... .10 yaars ... ............ ... .. ....... .. .... .. .. ... .11 years .......................... .. .... .... ... .. .

~

6 years ...... ......... ..... ...... .. ..... ..........7 years ................. .... .. .. ........ ... .......8 yearn ..... .. ........... .. ....... .... ...... .. .. ..9 yaars .... .. ... .. ........... ..... .... ..... .......10 years ... ........ .. ............ .. .... ... . .... ..11 years ........... .. ... ................ ... ... ....

Dack 56 only

6 years ...... ................ ...... .... ...... .... .7 years ..... ....... ... ............ .... ....... .... .8 yaars ..... .... ....... ........... ..... .. .........9 years .......... ..... .. .. ... ............... ......10 years .. ............ ... .................... ... .11 years .............. .... ...... ...... ........ ... .

11.69.69.8

10.412.111.7

14.411.413914.314.311.0

8.513.210.214.013.613.5

15.013.813.626.321.1161)

8.57.5

1298.9

10.010.6

11.12.69.7

14.313.014.3

272335242731

71312181925

224554

2

1

12

1165453

11

112

5.33.65.84.04.75.6

3.65.94,06.56.27.2

2.11.74.14.44.53.6

I 0.0

4.5

5.38.0

4.43.22.92.74.22.4

2.22.6

3.64.39.5

233736372731

101214

51223

353

1097

13

2

1489937

3

12

;

4.55.75.96.24.75.6

5.25.54.61.83.96.6

3.24.13.18.88.26.3

3.413.6

10.5

5.64.35.36.22.55.7

6.7

3.27.14.3

19.0

566848564661

191827312827

101111

710

9

312

3

221113131712

452211

11.010.6

7.89.47.9

10.6

9.88.28.9

11.19.17.8

10.69.1

11.26.19.18.1

10.34.5

10.5

12.0

8.8597.689

14.29.6

8912.86.57.14.34.8

12516313913912314!5

515368546772

243223322221

610

5554

434639282440

1111

4953

94137123120131

99

404971756868

213321212128

543117

443232312418

557453_

33

Table 6. IQ of children 6-11 years of age, by cHealth Exal

Quality group and age

~

6 years ............................ ...... .... ..... ..... ............ ....7 years ...... .......... .... ...... .. ................ .... .....c. .. ... ....8 years .... .. .... ... ... . ..... .... ............. ................ ... .. ....9 Vears ..... .......... ..... ....................... ..... ................10 years ..... .. .. .. .... .... ............ ... ............................11 vears . ............................... .. ... .... .. ... ... . ........ ....

~

6 yaars ..... .... .. .. .... ...... .... ................. ..... .... ...... .... .7 yaars ..... .. .... ..... ..... ...... .. .... ....... ... .....................8 years ... .. .... .. .......... ...... ..... ................................9 years .. .... .... ............................................. .... ... ..10 yearn .. .. .... .................................. ...... .. .. .... .. ....

11 years . ...... .... .... ........ ...... .. .... .. .... .. .......... .. ...... .

IC-IE

6 years .... ... .... ....... ..... .... ..... .... ....... .....................7 years ..... .. .... .. .. ........................................ .... .. ...8 years .... .. .... .... .. ........ .............. ...... .... .... .. .... ......9 years .......................... .. .... ...... ...... .... .. .... .... .. .. ..10 years .............. ................. ...... ...... .... ... ......... ...11 years . .... ........ .......... ............ .. .... .. .. .... .............

~

6 years ..... .. .. .. ....................... .... ........... .... ..... ......7 yean ....................... .......... .... ....... .... .. .... .. ... .....8 Vean ....... ..... .... ..... .. .... ....... ..... .... ..... ....... .... .... .9 years ... .. .. .... ...... .... .. .. ... .... ....... ..... ..... .... ...... .....10 Vears ..... .. .. ...... ...... ...... .... .... ...... ...... ...............11 years .. ............................ ... ... .... ... .. ... . .. .... .. .... .

Ill—

6Vea~ ..... ..... .. .......... .... .. ..... ... .............. .. .. .... ......7 years ..... .... ...... .. ...... ...... ........ .... ...... ............ .. ...8 yearn . .... .. .... ..... . .... .......... .... ........................ .. .. .9 years . ..... ...... .. .. ...................................... ...... ....10 years .... .... .. .... ....................... ... .. .... .... ........ ....11 years . ............................................ ....... .. .........

Deck 56 only

6Veam ...... ... .. .... .. .... ............................ .. ... ..... .....7 years .. .... .... .. ..... ................. .......... .... .... .. ...... ....8 yea fi ....................... .... ..... ...... ..... . ..... ... .. ..........9 yearn ...... ........ .. ..... ...... ... ... ..... ........... .... ...... .....10 ymrs .. .. ..... ..... .. .. ........ .......... ..... ..... .... ............11 years ........... ..... .. .... ......................... ... .. .. .. .. ... .

IIitylatio

n

510646606598580566

184219303279308346

94121

98114110111

202922191925

248187171146120123

453931282321

—

NJpand age: sample size, mean, standard deviation, and selected percentiles,;urvey Cycle 11, 1963-65, unedited data

Percentilex SD

5th 10th 25th I 50th 75th 90th 95th

97.096.897.696.797.896.0

99.499.799.2

100.898.897.5

96.199.8

100.398.398.898.1

100.399.1

101.395.396.9

102.7

92.891.395.193993.794.7

92.787.296.493.195.889.7

13.113.513.714.715.815.2

14.413.113.513.714.117.2

13.113.615.115.116.216.1

10.78.8

12.513.115.715.2

13.214.415.815.115.616.8

16.619.017.517.124.517.7

73.774.274.071.670.870.0

75.678.277.878.573.467.6

72.375.776.572.171.266.1

0.085.780.2

0.00.0

73.6

70.767.358.168.866.467.8

65.454.964.263.650.760.2

79.080.279.577.074.973.7

81.584.081.982.480.573.9

75.580.182.079.275.875.2

84.988.182.979.469.786.2

74.572.375.075.371.272.6

69.159.775.268.956.570.2

IQ

88.288.189.186.386.985.4

90.391.490.391.089.086.0

87.491.889.780.490.288.8

95.894.095.684.584.592.8

82.780.983.682.883.482.9

80.469.782.781.683.775.6

97.896.797.796.598.997.4

99.299.599.5

100.699.898.7

96.6100.1

98.697.798.898.6

99.999.5

103.393.198.799.4

93.092.395.694.094.995.9

93.489.393.793.9

101.592.4

105.9104.8106.3107.5108.8106.4

108.8108.6108.3111.0108.6108.4

104.7108.4110.7107.7108.1108.8

107.4105.7108.7107.0107.0116.2

102.5101.2104.7104.8104.6106.2

105.7103.0109.4106.6108.7

99.7

112.7113.4115.6116.0117.3113.7

15.416.715.720.016.419.7

12.816.619.219.521.615.7

13.310.214.412.715.521.8

08.008.114.412.612.116.9

12.410.217.215.526.709.7

118.0121.9120.!3121.7122.8120.6

122:3121.5122.2123.4121.2126.2

117.1122.4123.3124.3128.’7121.1

114.!3113.8119.4115.1120.2123.2

114.7114.0123.4116.7119.!3122.8

114.7115.2122.2118.!3129.5121.3

NOTE: n = sample size, ~ = mean, SD = standard deviation.

34

Table 7. Number and percent of children 6-11 years of age, by geoCycle 11,

Quality group and aga

1A-

6 years ............. .. .. .... .. .... ...... .... ............ .... .. .... ....... ... ............ ... ...... .. ...

10yams ... ...... .... .. .......... ........ ......... ..... ...... ............... . ... . . ..... ........... ...11years.............................................................................................

6 yaars ........... .. .. ........ ... ....... .... ....... ... .. ............ ... . ...... .... .... ....... ..... ....7 yaars ....... .... ...... ................ ...... .......... .. .......... .... .... .. .... . .... ........... .. ..8 years .. .... ... ... ..... ................. .... ..... ...... .... ............. .... .... . ....... .. ...........9 years .. .. ..... ...... ... ..... .... ............ .... ...... .... .. .... ................ . .... ..... .. ..... ...10 ymn .... ..... ....... ... . .. .. ................. ..... ...... .... .. .... ........... ..... ... ... .... .....

11 years ......... .... ...... ... ... .. ...... .. .... .. ............ ... ....... .. .... .. ........... ..... ......

IC4E

6 years . .... ..... ....... ..... .... ....... ..... .......... ............ .. ... ..... ..... ..... .... ........ ...7 yaam ....... ..... .... ..... .................. ...... .... .... ...... ........... ..... . ... ... ... ..........

9 +eam ....... ..... ..... .......... ................. .... ....... ... ....... ........... ..... . ..... .... ....10 vwrs .... ....... ... . ... .. ...... .... ........... ....... .... ..... ...... .. .............. ......... .. ...11 years .. ...... .. ......................... ..... ...... .. .............. ... ....... .. ....... ... ..........

6 years .... ... ......... .................. ... ..... ........ ...... ... ..... ........ ... . ...... ... . ..... ....7 years ....... .. .. ..... ........... ................ .... .. .... ..... ....... .......... ..... ...... ..... .. ..8 yea= ........... .... ... .. ... ..... ..... ................... .. .......... . ..... .... ........... ....... ...9 years ...... .. .. ...... .. ....... ... .... .................. ........ .. .... .. .... ..... ............ ..... ...10 ymn .............. ..... .. .... ........... .... ............ ..... .... .. .. .. ..... . .... ....... ... .. ....11 yearn . .......... ...... ....... ..... ................ ... ... ...... .. .... ... ......... ........ ..........

6 yearn . ................ ... ....... .... ... ... ..... ........... .. .... ..... ..... ...... ...... .... ...... ....7 yaars .. .... .. .... .......... ...... ...... .... .. .. .............. .. .. ...... ... .. .... ............... . .. ..8 yaars ....... .... ............ ... ........... ... ... ................ ..... .. .... . .... ................ ....

10years ........... ..... .................... .... ...... ........ .............. ..... ... ....... . .... .....11 years .. ...... ... ............ .................. .... ..... . .... .. .. ..... ... ......... ... ........ ...... .

Deck 56 only

6 years ...... ..... .... .. ................. ... .. .... ...... ... ............. .... .. .... .. .. .... ............7 yearn ....... .... ...... ... . ............ ...... ... . ...... ..... ..... ...... ...... .... ....... .... ... .. ....8 years ........... ........ ... ..... ..... ........ ... ...... .... .. .... .. .............. .. .. .... .. .. .... ....9 years .. .. ............. .... ...... ...... .... ............ ..... ... .. ..... ...... ..... .... .. ..... ..... .. ..10 years ... ...... ........... ..... ..... . .. ... ............ ... ....... ..... ...... .... .......... ....... ...

11 years .... .... .... ...... .... .. .... ... ... .............. .... ..... ......... ...... .......... .. .... ... ...

aphic region, quality group, and age: Health Examination Survey963-65

Geographic ragion

Northeast

N um-ber

146171176157135137

465271737989

183714262225

689174

624148

352129

1258822

Per.cerd

28.626.528.026.323.324.2

23.723.723.426.225.625.7

19.130.614.322.820.022.5

30.027.640.9

5.336.816.0

25.021.928.124.017.523.6

26.712.825.828.6

8.79.5

Midwest

Num-bar

137169139149157150

5666

108938899

243624303426

311

2679

505138323228

674583

Per-cent

26.826.222.924.927.126.5

26.831.135.633.332.128.6

25.529.824.526.330.923.4

15.037.99.1

31.636.836.0

20.227.322.221.926.722.8

13.317.912.9I 7.934.814.3

South

Num-ber

108168158159150161

443638445768

232127283027

6367

3

765446472837

1013

6646

Per-cent

21.226.226.126.625.928.4

22.716.412.515.818.519.7

24.517.427.625.427.324.3

30.010.327.336.8

12.0

30.628.926.932.223.330.1

22.233.319.421.417.428.6

west

Num-ber

119137133133138118

526386697390

2S2733292433

575559

m4739323928

17141399

10

Per-cant

23.321.221.922.223.820.8

26.828.828.424.723.726.0

30.922.333.725.421.829.7

25.024.122.726.326.336.0

24.221.922.821.832.523.6

37.835.841.932.139.147.6

35

Table 8. Height in centimeters of children 6-11 years of age, by quality group, age, race, and sex: Sample size, mean, and standard devia.

Age, race, and sex

Total

6 years ................. .... ...... .... ...... ......7 years .......... ...... .... .. .... ...... .... .. .....8 years ..... ..... .................................9 years ...........................................10 yaars .... ..... ... .. .......... ................ .11 years ............... .... ...... .... .. .... .. ....

White

6 years ................ ...... .... ............ .....7 yaars ..... ...... .... .. .... .. .... .... .. ...... ....8 years ............ .... ....... .... .... ..... ...... .9 years ................ .......... ...... ..... ......10 years ... .......... ............................11 years ..................... .... ........... .....

Negro

6 years ..... .... .. .... ............................7 years ...........................................8 years ................. ..... .... ...... ..... ......9 years ..... ...... .... ........ .... ........... .....10 years ... ......... .. ...... ........... ...... ....11 years ... .. ...... .... .... .... .. ...... .... ......

Male

6 years ..... ..... ....... .... .. ... ....... ..... .....7 years .. .. .... .. .. .. .. ...... ...... .... ...... .....8 years .... ............. .... ..... ........... ......9 years ..... .. .. .. .... ............................10 years .........................................11 years ............... .... ..... ..... ............

Female

6 years ... .. .... ...... ............................7 yaars ................. ............ ........ ......8 years ............ .... ... .. ..... .................9 years ...... ...... .... ...... ..... ..... .... .......10 years .......... .... ...... .......... ...... .....11 years ... .... ....... ..... ..... .................

tion, Health Examination Survey Cycle 11, 1963-65

n—

510646

598580566

446554512513502496

628994787668

265322309315289295

245324297283291271

Y~ SD

Centimeters

118.4123.9129.7135.2140.5146.3

118.4123.9129.5134.8140.3146.3

118.8124.0130.5137.0142.2146.6

118.8124.4129.8134.9140.3145.8

118.1123.5129.6135.4140.8147.0

5.295.635.577.067.127.76

5.315.605.486.896.887.61

5.155.675.997.678.448.92

5.295.305.277.056.976.94

5.285.925.877.047.288.53

Qualit

—n

194219303279308346

171195263246269289

212137333754

100125147138156191

9494

156141152155

18

Centimeters

119.0124.8130.2136.0141.2146.8

119.0124.8130.2136.2141.1146.5

119.9126.3130.0134.5141.0148.8

119.5125.2130.5136.5140.8146.2

118.6124.3129.8135.5141.5147.5

4.995.406.226.016.977.07

5.055.366.286.046.817.00

4.575.036.065.628.017.21

4.915.226.285.825.926.60

6.065.616.176.187.917.57

Iroup

—n

94121

98114110111

80112

77104100

96

139

20101015

525757594757

426441556354

IC-IE

=l=_

Centimeters

118.5123.8130.0135.6139.4146.3

118.3123.6130.0135.5139.9146.8

118.4126.3130.3136.7134.5143.5

119.1123.5130.3135.3139.4145.1

117.6124.1129.5136.0139.5147.6

5.096.226.346.387.006.89

4,916.316.216.496.316.87

5.284.397.045.31

11.186.51

4.795.475.326.378.147.20

5.376.847.586.436.096.36

n

202922191925

192718181721

124123

1213

98

1010

8161311

915

+-F--122.0123.1128.5134.0141.4150.9

121.6122.7129.1133.8141.6150.5

130.6128.4125,9137.5140.1151.5

123.1122.3131.6133.3140.3148.6

120.4123.7126.5134.5142.7152.5

6.334.514.926.136.956.23

6.174.414.796.246.806.54

0.01.485.29

0.011.24

4.20

5.623.303.274.528.013.53

7.395.324.867.255.787.22

NOTE: n = sample size, ~ = mean, SD = standard deviation.

36

Table 8. Height in centimeters of children 6-11 years of age, by quality group, a!ie, race, and sex: Sample size, mean, and standard devie-tion, Health Examination Survey cyc~ 11, 1963-65-Con.

Quality group

1A IB IIAge, race, and sex

XISDn n n n

White male

6 yaars ...... ..... ............. .. ............ .....7 years ... .. .... ....... ................. .... .. ....8 yaara ..... ........ .. .. .. ........................9 years ........... ...... ..... .... .................10 years .............. ...... ..... ..... ..... .. .. ..11 yeers ... ...... ............ ..... .... ..... ......

White female

6 years ...... ...... .... ..... ....... .... ...... .....7 years ..... ............ .... ...... .. .... .... .. ....8 years ..... ....... ... ............. ..... .... .. .. ..9 years ...... .... .. .... ................. ..... ... ..10 years ... ...... .... .. .... .................. ....11 ymrs ... .. .... ...... .... .... ..................

Negro male

6 yaars .. .... ... ...... .. ..... .... ............ .... .7 years ... ......... ... .. .... ................. .....8 yeara ........... .... . ... .. ........ ... ..... ......9 yaars .. ... ..... ....... ..... .... ... ... .. .. .. .....10 yaars .... ..... . ... ............. ... .. ..... .....11 years .... .. .. ...... ................ .. .. .. .....

Nagro famale

6 years ..... ............ .... .. .... .. ... ... ... .....7 yaars .... .. .. .. ............ ..... ..... ...... .... .8 years ...... .. .... ... ................. .... .. .... .9 yaars ...... .... .. ... ....... ..... ................10 years .............. ...... .... ...... .... .......11 years ............... ..... ..... .......... .. ....

Centimeters Centimeters Centimeters

118.8124.3129.6135.0140.2145.9

117.9123.5129.4134.7140.4146.7

118.7125.0130.8134.2140.9144.6

118.9123.4130.3139.4143.1148.6

5.415.335.207.146.986.69

5.175.865.786.606.798.50

4.605.175.656.586.888.80

5.875.946.257.799.388.71

119.5125.2130.6136.6140.9146.1

188.5124.3129.8135.8141.3147.0

119.2126.1130.2135.3140.0147.6

121.5126.8129.9133.8142.0149.7

5.045.336.465.965.936.56

5.025.406.086.127.637.56

4.184.384.774.516.087.02

5.486.246.916.459.547.33

118.6123.4130.5135.3140.2145.8

117.9123.9128.2135.8139.8147.6

120.6125.9130.1135.4132.6142.4

115.8126.5130.4138.5136.3747.6

4.505.545.406.516.667.18

5.417.007.286.536,116.54

4.493.935.195.57

15.586.91

5.264.968.815.015.471.62

122.4121.7131.6133.3141.2146.0

120.4123.5126.7134.2142.0152.1

130.6128.4

132.1150.8

127.3125.9137.5146.0153.0

5.342.633.274.527.923.12

7.395.414.977.575.797.68

0.00.0

0.05.66

0.05.28

0.00.00.0

227286

85111131123137167

8684

132123132122

151315151823

68

22181931

445446534245

365831515651

73

1065

12

66

104

:

1112

9898

8159

108

13

11

12

14111

270275256259

219268242238246237

373539363234

255455424434

NOTE: rr = sample size, ~ = mean, SD = standard deviation.

37

Table 9. Sitting height in centimeters of children 6-11 years of age, by quality group, age, racer and sex: Sample size, mean, and standarddeviation, Health Examination Survey Cycle 11, 1963.65

Age, race, and sex

Total

6 years ...... .. .. ...... ...... ...... .... .... ...... .. .... .. .. .....7 years ........... .... ...... .. .... ..... ............ ... .. ........8 years ..... ..... ...... ..... ............... .. ..... .. ... ..... ....9 years .... .. ... .. ... .. ...... ..... ..... .......... ...... .........10 years ... .... .. .... .. .... ...... .... .. ........................11 years ....... ...... .. .. .................................... ..

White

6 years ................. ..... ... ....... ............ ..... .. .. ....7 years ............ ............... ..... ........... ...... ........8 yaars ...... ... .. .... .. ...... .... .. .. .. .... ..... ..... ...... ....9 years ..... .... ...... . ................. .. ........ .. .. .. .. .. ....10 years .. .. .... ...... ...... .... .... .. .. .. .. .. .. ...... .........11 years ... ..... ....... ... .....................................

Negro

6 years ................. ...... .... .... ........ .. .. ...... .. .. ....7 years ................ .......... ...... .... .. ...... .. .. .. .. .....8 yaars ..... ...... .. .... .......... ...... .... ...... .... ...... .. ..9 years ..... .. .... .... ..... ... ... ........... .... .. .. .... .. .. ....10 years ........ .. .. .. .......... .......... .. ...... ... ..........11 years ..... ...... .. .. ...... .. .. ...... ... ....... .... ..........

Male

6 years ..... ............................ ...... .... .. .. .. .... .. ..7 years .... ................... ..... .... ...... ... ......... .... ...8 years .......... ....... ... .... ...... ...... ........ .... .... ....9 years ....... .. .. .... ..... ...... ....... ....... ... .......... .. ..10 yaars .. ...... ....... ......... ............ .... .. .... .... .....11 yaars .... .... .. .... .... ........ .... .. .... ..... ..............

Female

6 years ..... ................................. ..... ..... ..... ....7 years ................. ..... ..... .... .. ... ............. .... ....8 years ................ .... .. .......... .. .......... .. .... .. .. ...9 yaars ................ ..... . ...... ..... ..... ..... ... .. ...... .. .10 years ... .. .. ...... .. .. .. .... ...... ...... ........... . .... ....11 years ..... .. .. ...... ......... .. ..... .... .. .. .. .. ........ ....

n

510646606598580566

446654612513502496

628994787668

265322308315288295

245324297283291271

1A

2-ISCentimeters

64.466.568.771.073.175.8

64.666.769.071.273.376.0

62.764967.169.472.073.9

64.866.869.171.173.175.5

63.966.168.470.873.276.1

2.892.922.973.373.333.76

2.822.862.853.233.193.70

2.872.793.123.714.003.75

2.762.652.803.433.283.26

2973.123.103.303.394.23

Quality group

n

194219303279308346

171195263246269289

212137333754

100125147138156191

9494

156141152155

*

—SD

Centimeters

64.767.069.271.473.475.8

64.967.269.671.773.775.8

63.565.867.169.271.474.8

65.167.669.771.773.375.5

64.366.368.871.273.576.1

2.822.853.142.943.223.48

2.852.822.882.833.073.43

2.322.953.532.803.383.73

2.622.833.072.872.863.08

2.862.843.162.993.563.8(3

—n

9412198

114110111

80112

7710410096

139

20101015

525757594757

426441556354

IC4E

=

Centimeters

64.566.888.871.172.875.5

64.766.969.371.273.176.0

62.866.367.270.370.072.7

65.167.068.071.273.174.6

63.888.788.671.072.676.5

2.643.183.013.083.573.61

2.383.212.873.043.393.34

2.572.883.043.374.224.07

2.302.803.153.113.403.72

2.673.842.823.043.703.24

—n—

202922191925

192718181721

124123

1213

98

1010

8161311

915

-5=-Centimeters

66.766.268.370.273.877.8

66.766.469.070.374.278.0

65.764.065.568.371.275.2

66.665.770.070.573.276.2

66.866.667.269.974.678.8

2.792.373.063.253.493.91

2.862.372.813.323.443.86

0.00.072.71

0.03.61

3.65

2.021.661.882.964.152.39

3.832.813.253.572.804.zX2

NOTE: n=samplesize, ~ =mean, SD= standard deviation.

38

Table 9. Sitting height in centimeters of children 6-11 years of ege, by quality group, age, race, and sax: sample size, mean, and standarddeviation, Health Examination Survey Cyclell, i963-65-Con.

Age, race, and sex

White male

6 years . ... .. ...... .... ........... ..... ........... ...... .. .. ....7 years ........... .. ... .... .................. .......... .... .. ...8 years .. ... .... .. ... ....... .... ............ ...... .... ...... .. . .9 years ........... ...... .. ......... .. .. ................. ..... ...10 years .............. .. .. ... ..... .... .... ............. .... ....11 years ................... ....... .... .... ...... ...... ...... ...

White famale

6 years . .... ...... ...... ..... ... ............ .... .. .. .... .. .. ....7 years ..... .... ......... ... ..... ................. ...... .... . ...8 years ................ ...... ............ ... ................. ...9 years .. .. .. .... . ........... .. ... ..... .... ........ .... .........10 years ......... ... ....... ...... .... ...... ..... .... .. .........11 years .............. .. ............. ....... .... ..... .. .. .. ....

Negro male

6 years ............ .... ...... .... .. ......... ................. ...7 years .... ... .... ..... .......... ..... .. .... .. .. .. .... ..........8 years . .. .. .. .... ..... .... ....... .......... ...... .... . ..... ....9 years ...... .... ..... .. ............... ... .. .. .... .... .. .... ....10 years ... ....... ... ...... ................ .. .... ...... .... ....11 years ..... .... . .. ....... ... .. .... .................. ..... ....

Negro female

6 years . ......... ................. .... ...... .. .... ..... ..... ....7 years ...... .... .. .... .... ........ ..... ... ............. .... .. ..8 years . .... ..... ...... ................. .... ............ .... .. ..9 years ...... .. ... . ... . ... ......................... .. ........ ...10 years .... .... .. .... ..... ....... ................ .... ...... ...11 years .. .. .... .. .... .... .. .. .. ..... ..... ............ .. ... ....

n

227286270275256259

219268242238246237

373539363234

255455424434

*SD

Centimeters

65.167.169.371.573.375.8

64.166.468.771.073.376.3

63.265.667.568.471.273.0

62.164.566B70.372.674.8

2.712.642.703.273.163.22

2.863.042.983.173.244.15

2.582.453.023.563.662.53

3.192933.183.664.184.53

Quality group

—n

—

85111131123137167

8684

132123132122

151315151823

:22181931

—

IB

Centimeters

65.467.869.872.073.775.6

64.466.469.171.573.776.4

63.666.367.869.470.774.6

63.255.156.559.172.075.2

2.612.863.092.752.633.05

3.002.842.842.903.483.86

2.202.272.372.873.343.30

2.783.884.112.833.394.06

—n

445446534245

365831515851

73

1065

12

66

10453

—

IC-IE

E

Centimeters

65.167.068.671.373.475.4

64.166.768.871.172.976.4

63.866.566.870.270.671.6

61.866.267.670.558.377.1

2.172.653.203.153.183.31

2.533.6a2.302.953.553.32

2.041.721 .m2.814.553.75

2.873.474.044.574.261.20

—n

—

1112

9898

815

9108

13

11

12

14111

—

2LESD

Centimeters

66.765.870.070.573.776.5

66.866.868.070.174.778.9

65.763.9

68.675.2

64.;65.568.373.775.2

2.101.641.882.964.061.76

3.832.823.303.722.764.54

0.00.0

0.05.16

0.02.71

0.00.00.0

NOTE: n = sample size, ~ = mean, SD = standard deviation.

39

Table 10. F EV ~ of children &1 1 years of age, by age, sax, and race: Sample size, weighted sample size, standard deviation, standard error of the mean,mean, an~ salected percentiles, Health Examination Survey Cycle 11,1963-65

Percentile

SD S E~ Y

I

—

5th 10th 25th 50th 75th 90th 95tfl

Age, sex and race N

23,784-

4,098

4,084

3,986

3,957

3,867

3,792

12,081

n

Total

6-11 years..,.., . . . . .

6 years .. .. . . .. .. . . .. .. . . .. . . . . .. . .

7 years . . . . . . .. . .. . . . . . . . .. . . . .. . . .

6 years .. .. . . . . . . . . .. . . . . . . . . .. . . . .

9 years . .. .. . . .. . . . . .. . . .. .. . . .. . . .10 veals .. . . . .. . . .. . . . . .. . . . . . . . . .

11 years .. . . . . .. .. . .. . . . . .. . . . . .. . .

Male—

6-11 years .. . . . . .. . . ..

6 years . . .. . . . . . .. . .. .. . . . . .. . .. . . .

7 years .. . .. . . . . .. . . . . . . . . . . . . . . . . .8 years . . .. . . .. . .. . . .. . . . . .. . .. . . . .

9 years . .. .. . .. . . . . . .. . . . . . . . . . .. . .10 years . . . . . . . . . .. .. . . .. . . . . . . .. .11 years . . .. . .. . . .. . . . . . . .. . . . . . . ..

Female

6.11 years .. . . . . . . . . .

6 yea . . . .. .. .. . . . . . .. . . . . . . . . . .. .7 years . . .. . . . .. . . .. .. . . .. .. . .. . . . .

6years . . . . . .. . . . . . . . . . . . . . . . . . . . .

9 years . . .. . . . . . . . .. . . . . . .. . . . .. . . .

10 years . . .. . . . .. . . . . . . . . . . . . . .. . .11 years . .. . . . . . . . . . . . . . .. . .. .. . . .

White

6-11 years . . .. . . .. .. . .

6 years .. . .. . .. . .. . . . . .. . .. . . . . . . . .

7 years . .. .. . .. . .. . . .. . . . .. . . . . . . . .8 years . .. .. . .. . . .. . . . . . . . .. . .. . . . .

9 years . . .. . . . .. . . .. .. . . . . . . . . . . .. .10 years .. . .. .. . . .. .. . . . . . . . . .. .. .

11 years . . . .. .. . .. . . . . . . . . . . .. . .. .

Negro

6-11 years . . .. . .. . . . .

6 years . .. . .. . .. . . . . .. . . . . . .. . .. .. .7 vears . . .. . . . . .. .. . . . . . . . . . . . . . . . .8 years .. . . . . . . . . . . . . . . . .. . . . . .. . . .

9 yaws. . . .. . . .. . . . . .. .. . . .. .. . .. . .

10 years .. . . .. .. . . .. .. . . .. . . . . . . . .11 years . . . . . . . . . . . . . . .. . .. . . . . .. . .

7,119

1,111

1,241

1,231

1,184

1,150

1,192

3,632

575632

618W3

576628

3,487

428.6 9.06-

13.1911.44

11.01

12.24

13.58

14.26

11.43

16.5416.24

15.8219.7115.35

22.84

6.14

1,594.7 947.3—

730.3923.3

1,043.51,140.2

1,253.1

1,433.2

884.2

819.0

966.31,160.1

1,202.3

1,276.0

1,458.3

911.6

677.6

883.5

974.91,111.2

1,230.51,383.6

965.2

1,071.7—

858.11,008.2

1,147.5

1,268.61,404.3

1,570.8

1,130.1

905.21,077.9

1,244.31,335.7

1,447.51,619.0

1,023.1

7929

966.31,073.5

13)8.61372.5

1,550.1

1,083.4

1,283.4—

1,007.31,166.6

1,326.11,463.7

1,615.0

1,805.1

1,344.2

1,054.9

1,235.11,398.1

1,523.7

1,663.11,855.3

1,227.8

966.4

1,150.6

1,259.3

1,368.8

1,567.61,765.7

1,305.1

1,584.0 1,872.4 2,172.0 2,345.0

256.0263,7

284.1

328.1

345.5

369.0

425.1

254.9267.6268.5

331.7344.6

384.6

427.2

246.0

247.6

282.5

311.1

339.7

388.5

428.4

1,172.2

1,353.1

1,520.7

1,682.1

1,831.4

2,059.0

1,848.8

1,223.91,407.01,589.3

1,745.71,878.5

2,098.0

1,538.2

1,172.31,351.2

1,528.1

1,882.61,821.3

2,054.1

1,622.5

1,227.41,411.1

1,589.31,751.7

1,658,3

2,096.3

1,508.3

1,128.4

1,295.1

1,470.0

1,624.5

1,772.81,997.1

1,585.9

1,339.7

1,521.51,711.6

1,905.4

2,058.6

2,308.3

1,929.5

1,386.3

1,581.21,775,7

1,967.8

2,114.92,330.3

1,808.0

1,284.4

1,458.9

1,628.3

1,814.8

1,986.42,274.8

1,886.0

1,361.2

1,535.01,724.5

1,919.12,068.12,329B

1,728.2

1,240.71,413.01,593.1

1,760.31,841.8

2,098.4

1 ,EJ34.71,679.0

1 @84.3

2,086.62,270.7

2,541.0

2,213.6

1558.6

1,728.51.929,1

2,165.72,309.0

2,578.3

2,1 ?4.0

1,417.1

1,598.8

1,790.1

2,018.3

2,224.6

2,486.6

2,192.7

1,520.2

1,867.21,867.0

2,117.52,286,42,564.1

1,880.5

1,598.91,786.8

1 /880.3

2,215..02,385.1

2,701.8

2J73.1

1,639.2

1,817.82,010.2

2,261.2

2,409.72,728,4

2,295.3——

1,535,2

1,~8.O1317.1

2,138.6

2,380.4

2,646.8

2,363.4——

1,809.51,792.81,882.2

2/226.1

2,381.62,725.8

2,139,8

2,0622,074

2,0262,0121,9831,924

11,703

536

608613

581

564

584

6,100

2,016

2,010

1,960

1,945

1,8081,888

20,403

13.01

11.22

14.34

14.06

16.97

16.04

9,19

1,118.8

1,297.51,449.8

1,616.4

1,783.0

2,016.9

1,616.3

950

1,0631,0351,019

1,0141,019

967

155172

192

156

142167

3,508

3,4973,413

3,3933,3243,267

3,272

570570580

534

530507

251.4

280.0280.1324.6339.4384.7

404.2

265.0

259.2262.1

315.8

330.3371.9

13.82

11.5312.38

13.2112.3913.34

13.36

17.97

27.1921.84

20.7830.3335.73

1,166.8

1,371.71,5399

1,702.91,868.22,065.2

1,469.7

1,076.41,241.81,403.9

1,555.2

1,665.11,882.5

765.7

946.21,070.1

1,161.01,283.61,452.5

854.2

880.1852.7951.2

1,057.2

1,123.61,267.6

878.01,041.11,176.6

1.288.71,425.21,807.9

967.8

722.2924.4

1,030.8

1,171.6

1,262.61,466.9

1,023.01,208.31,355.7

1,488.61,647.51,834.1

1,170.5

914.91,076.41,207.3

1,330.6

1,483.81,634.2

1,183.8

1,358.81,542.01,703.21,848.32,080.3

1,435.5

1,085.11,211.11,388,4

1,541.2

1,681.21,893.5

1,400.5

1,612.81,788.3

1,887.5

2,050.32,324.3

1,491%

1,898.41,887.4

2,063.5

2,230.32,480.5

NOTE: II =sanlplesize, .Y = estimated numher, )f I ldren in thou~~nds, Sl) =standard dwiation, SK~ =standardt urofthemean, X =mean.

40

Table 10. FEV, of children 6-11 years of ag by age, sex, and race: Sample size, wight~sample size, standard dwiation, standard error of the mean,lectedpercentiles,H ealthExaminationS urveyCyclell, 1883.65-Con.

PercentileSD SEX F

5thI

10th 25thI

50th 75thI

80th 95th

an, and-

NAge, sex and race n

White male

6-11 years............ 1,155.5

912.11,112.81,25-$.41,370.71,476.01,674.7

1,047.6

1,365.2

1,067.21,257.41,423.51,557.81,710.71,892.8

1,250.9

1,847.5

1,250.31,428.01,610.01,788.61,821.32,134.3

1,525.4

1,956.6

1,398.01,E&12.21,789.81,884.32,134.02,348.3

1,823.9

3,153 10,391 427.0 11.74 1.672.7 2,240.0

1,560.21,738.81.938.42,163.62,327.62,587.0

2,133.2

2@l .5

1,848.31,824.52,017.82,284.82,427.52,744.8

2,314.1

1,012.9

829.6989.0

1,166.21,262.21,326.31,471.1

932.2

6 years .. . . . . . .. . . . . .. . . . . . . . . . . . . .

7 yeas ............................8 yeare ............................9 years ............................10 yaws. .........................11 years...........................

488551537525508542

?,947

1,7871,7811,7391,7301,6921,662

10,012

257.62s3 .5268.9327.9336.1376.2

424.2

18.6916.5516.9321.55139422.11

7.82

1,238.31,425.61,6CM.O1,773.21,811.92,128.4

1,558.2

White female

6-11 year. ...........

6 years ............................7 years............................8 years, ...........................9 years............................10 years..........................11 years..........................

Negro male

6-11 years............

1,420.01,615.31,797.62,015.02,234.72,498.6

1,978.5

461512498484505477

484

1,7221,7161,6741,8631,6321,805

1,842

233.1244.0276.0304.3333.7388.0

379.7

13.0210.8816.5914.4217.3916.85

17.70

i ,133.41,315,91,473.31,628.71,802.72,039.6

1,497.0

695.7910.1

1,002.11,123.51,254.21,433.2

922.8

846.0985.5

1,104.71,231.21,396.51,570.0

1,030.1

987.51,167.41,293.11,417.01,606.11,790.8

1,217.2

1,137.41,316.31,484.61,835.71,789.62,021.8

1,480.7

1,281.81,471.91,845.31,824.12,009.02,293.2

1,745.8

1,5m.81,715.81,824.62,138.42,362.22.677.6

2,115.4

847879748683

523

283286279268284255

1,629

22.0636.3735.7525.0845.4255.21

14.26

6 Veal ............................7 years ............................8 years............................9 years ............................10 yews. .........................11 years..........................

Negro female

6-11 years........

217.2286.5249.6285.7325.7371.4

424.2

1,131.21,291.01,486.41,586.91,675.11,884.4

1,422.2

736.5806.2

1,084.61,046.11,118.11,284.8

776.2

866.8951.7

1211.51,171.21,238.71,491.2

921.3

881.91,115.41,323.31,364.21,509.11,842.0

1,128.2

1,138.71,288.11,491.11,581.81,m5.71,801.9

1,373.5

1,27; .71,44891,681.41,783.91,80S.62,079.1

1,7089

1,407.11,646.11,852.51,975.82,040.02.304.6

1,861.9

1,344.11,501.51,718.92/027.12,053.82,378.0

1,472.S1,77691,921.32,088.52,226.02,475.1

2,165.0

1,573.11,613.61,862.12,153.52Z35.42,463.7

6 years............................7 years............................8 y=l’e. ...........................9 yeafs ............................10 years ..........................11 years..........................

7293

113847784

—

281284281265234253

296.1241,6282.5334.3334.6372.3

36.8026.9819.8838.3636.6239.00

1,019.91,192.11,312.01,541.31,655.11,860.5

550.4827.1920.2

1,062.61J?OO.51,245.2

673.1903.6975.6

1,172.11,271.11,372.8

804.91,038.91,085.71295.81,446.61,6279

1,008.31,180.01,268.31,515,61,624,31,886a

1,206.71,335.81,501.11,730.01,874.82,117.1

NOTE: n = aempIe size, N = estimated number of children in thousands, SD = standard deviation, SEg = standard error of the mean, 2 = mean.

41

Table 11. FEF25.75Y0 of children 6-11 years of aae. bv aae. sex. and rata: Samde size. weiahted samDla size. standard deviation. standard error of the

an~ kkka~ percentiles, Health Examination ;urvey Cycle 11, 1963-65=

mean. mea

PercentileSD SEX x

5th 10thI

25th 50th 75th 90th I 95th

Age, sex and race N

23,764

n

7,119

Total

6-11 years.,., . . . .

Milliliters

671.4 16.45_

22.5124.11

21.53

26.8422.94

30.47

21.65

2,173.6 1,1522 1,348,3 1,704.5 2,138.1—

1,752.11,959.2

2,109.0

2,233.4

2,372.6

2,623.3

2,158.1

1,798.0

1,986.1

2,154.9

2,244.5

2,360.52,592.1

2,115.2

2,589.9 3,036.5 3,317:0

1,111

1,241

1,2311,164

1,160

1,192

3,632

575

632

618

603

576

628

3.487

4,0984,0s4

3,8863,857

3,867

3,792

12,081

529.8539.4

573.6635.9

652.8

719.8

657.2

1,762.01,968.6

2,080.32,259.3

2,387.1

2,621.7

2.190.6

926.31,085.21,168.11,245a1,356.4

1,420.1

1,179.5

931.81,067.71,244.3

1,332.9

1,388.0

1,382.6

1,127.9

1,119.91,298.S1,346.0

1,463.8

1,574.51,697,1

1,364,1

1,144.4

1,304.61,418.8

1,519.6

1,588.8

1,648.0

1,310.1

1,407.91,582.0

1,677.01,830.7

1,837.1

2,140.2

1,743.1

1,444.51,623.5

1,774.7

1,853,4

1$32.4

2,105.7

1,662.9

2,100.52,310.3

2,459.52,652.3

2,821.93,067.4

2,605.6

2,143.3

2,368.32,503.2

2,644.4

2,812.7

3,045.6

2,576.0

2,419.72,672.6

2,801.73,084.4

3,202.3

3,519.4

3,025.8

2,429.1

2,752.52,837.1

3,060.4

3,174,5

3,479.5

3,046.7

2,589.02,6S6.22,970.2

3,314.6

3,46s.0

3,768.4

3,300.7

2,633.4

2,942.5

3,012.33,306.8

3,457.2

3,731.0

3,335.5

Male—

6-11 years, . . . . . ..

6years .... ...... ...... ...... ......7 years . . . .. . . . . .. .. . .. . . .. . . . .. . . .

8 year.%.. . . . . .. . . . . .. . . . . .. . . . . . . .

9 years . . . . .. . .. . . . . . . . . . . . . . .. . . . .

10 years .. . . . . .. . . . . .. . .. .. . . .. . ..11 years . . . .. . . . . . . .. .. . .. . .. . . . . ..

2,082

2,074

2,026

2,012

1,9831,824

11,703

542.4

559.4

568.5

591.7

657,5

708.1

685.3

26.23

29.9828.29

37.86

29.35

50.34

19,85

1,793.9

2,006.1

2,152.7

2,265.6

2,385.6

2,584.1

2,156.2

Female

6-11 years . .. . . . . .

1,100,8

1,292.61,269.81,402.3

1,563,01,753.3

1,344.2

1,364.2

1,547.31,593.41,793,1

1,942.7

2,188.9

1,701.6

1,706.6

1,932.92,046.62,222.8

2,368.12,661.3

2,134.9

2,059.5

2,267.02,416.92,665.42,834.43,081.5

2,586.6

2,415.4

2,567.82,756.03,122.93,239.1

3,569.1

3,032.1

2,582.4

2,782.42,940.93,328.8

3,475.7

3,794.2

3,325.7

6 years .. . . . . . . . .. . . . . . . . . . . . . . . . . .

7 years . . . .. . . .. .. . . .. .. . . .. . . . .. . .8years . .. . . . . .. . . . . . . . . .. . . . . . . . . .

9 years . . . . . . . . . . . . . . . . . .. . . . . .. . . .10 years .. . .. . . . . .. . . . . . .. . . . . . . . .

11 years . . . . . . . . . . . .. . .. .. . . .. .. . . .

White

6-11 years . . . . . . .

636

6086135815s4564

6,100

2,016

2,0101,9601,9451904

1,86S

20,403

514.5

515.2571.5678.7648.1728.7

670.5

27.46

26.5833.3731.4729.4442.82

16.89

1,728.2

1,929.92,026.02,252.82,3S8.72,6Kt.4

2,170.8

922.41,108.41,097.71,202.01,344.7

1,468.0

1,149.8

1,403.11,576.71,684.91,810.9

1,842.2

2,149.6

1,741.6

1,436.91,645.9

1,617.4

1,934.41911.5

2,061,4

1,7439

1,951.12,103.32,227.4

2,367.0

2,633.1

2,159.2

2,080.5

2,309.72,461.92,651.6

2,812.73,073.6

2,615.0

2,420.22,653.72.793.93,112.8

3,193.73,532.5

3,061.8

2,586.6

2,8%.32,967.83,322.8

3,474.3

3,780.7

3,274.8

6 years . .. . . . .. . . . . . .. . . . . .. . .. .. . .7 years . . . . . . . .. . .. . . . . .. . . . . . . . . . .8 years . . .. . . . . . . . . . . .. . . . . . . . .. . ..9 yaars .. .. . . .. .. . . . . .. . .. . . . . .. . ..

10 years .. . . . . . .. . . . .. . . . . . . . . . . . .11 years . . . . . . . . . . .. . . . .. . .. . . . . .. .

9501,0631,0351,019

1,014

1,019

987

156172

192

158

142

167

3,508

3,4973,413

3,393

3,324

3,267

3,272

570570

560

534

530507

530.2535.3559.1637.3

647.0

719.3

676.6

528.5564.7

653.1

622.2

6s0.6724.5

26.2322.7123.2526.33

19.75

29.58

50.75

46.88

60.66

56.74

58,3581.177323

1,753.01,962.02,085.32,262.3

2,384.82,632.3

2,194.7

1,S16.2

2,017.8

2,121.8

2,315.62,40S.1

2,552.4

908,31,079,51,168.2

1.227.8

1,373.11,431.8

1,166.5

1,027.4

1,112.3

1,187.1

1,428,4

1,214.01.356,9

1,112.31,293.31,346.51,453.8

1,577.4

1,714.2

1,370.6

1,183.41,322.2

1,349.3

1,576,9

1,586,01.579.6

Negro

6-11 years., . . . . . .

6 years . . .. .. . . . . .. . . . . . . . .. . .. . . . .

7 years . .. . .. . . .. . . . .. . . .. . .. . . .. ..

8 years .. .. . . .. .. . .. . .. . .. . . . . .. . . .

9 years .. . .. . . . . .. . .. . .. . . . . . . . .. . .

10 yaars . .. . . .. . . . . .. . . . . .. . .. . .. .11 years .. . .. . .. . . . . . . . . . . . . . . . . . . .

1,798.2

2,00S.8

2,144.7

2,274.9

2,428.62,555.8

2,163.22,332.8

2,451.1

2,652.3

2.686.33,038.2

2,454.42,771.0

2/638.0

3,054,5

3,2229

3,447.2

2,772.23,071.6

2,991,5

3,248.8

3,375.7

3,664.2

NOTE: n ❑ wmplc $i?e. IV = estimated number of children in thousands, S1) - standurd deviation, SEX = standard error of the mean, ~ = mean.

42

Table 11. FE F25.75% of children 6-11 years Of age, by age, sex, and race: Sample size, weighted sample size, standard deviation, standard error of themean, mean, and s-elected percentiles, Health Examination Survey Cycla II, 1963-65-Can.

PercentileSD SEX F

5th 10th 25th 50th 75th 90th 95th

Age, sex and race Nn

White male

6-11 years .. . .. ..

6 years .. . .. . .. . . . .. . . . . .. . . . . .. . . .

7 years . . .. . . . . .. . . . .. . . .. .. . .. . . . .8 years . . .. . . . . . . . . . .. . . . . . . . .. . . . .9 years . .. . .. . .. . . . . . . . .. .. . . .. .. . .10 years .. . . .. . . . . .. . . . . .. . . . . .. . .

11 years . . . . .. . .. . .. . . . . .. . .. . . . . .

White female

6-11 years .. .. . .. .

6years, . .. . . .. . . . . . . . . . .. . . .. . . . . .7 yams...........’ . . .. . . . . . . . . .. ..6years . .. . . . . .. . . . . . . . . .. . . . .. . .. .9 yaws. . . . . . . . .. .. . . .. . . . . .. . . . . . .10 year....,..........., .. . . .. . . .11 years......, .. . . . . . . . . . . .. .. . . . .

Negro male

6-11 years .. . . .. . .

6 years . . . .. .. . . . . . . . . .. . . . . . . . . . . .

7 years . . . . . .. . . . . . . . . . . .. . . .. .. . . .

8 years . . .. . .. . .. . . . . .. . . . . . . . .. .. .9 yearn . . . .. . .. . . . . . . . .. . . . . . .. . . .

10 years . .. . . .. .. . . .. . . . .. . . . . . .. .

11 years . . . . . . . .. . . . . . . . . . . . . . . . . ..

Negro female

6-11 years .. . . . . .

6 years . . . .. .. . .. . . .. . . . . .. . . . . .. . .7 years . . .. . . . . .. . . .. .. . . .. . . . . .. . .

6yeara . . .. . .. .. . . . . . .. . .. . . .. .. . . .

9 yaara . . . . .. . . . . . . . . . . .. . .. . .. . . . .10 years . . . . .. . . . . .. . . . . .. . . .. . .. .

11 years . . .. . .. . .. . . . . . . . . . . . . .. . . .

Milliliters

3,153 10,391 658.3 20.27 2,169.8 1,180.7 1,388.4 1,740.9 2,154.2 2,802.8 3,023.9 3,315.6

489

551

537525509

542

2.947

461

512498484

505477

484

1,7871,781

1,7391,730

1,6921,662

10,012

1,7221,7161,6741,6831,632

1,805

1,842

538.6551.5

558.2807.7652.8

704.9

882.5

519.8514.3553.7686.7640.7

731.7

651.2

29.60

26.2930.2839.87

25.0348.71

1,760,1

2,004.7

2,143.42,261.22,398.3

2,592.4

2.151.5

920.61,063.7

1,228.21,315.31,411.91,408.0

1,125.0

1,140.3

1,288.51,420.81,504.21,603.6

1,886.9

1,295.9

1,438.2

1,628.01,766.71,832.51,948.7

2,110.8

1,656.7

1,784.71,965.5

2,152.82,225.62,369.02,594.8

2,112.0

2,113.72,366.2

2,506.82,653.92,816.53,047.2

2,571.5

2,411.22,745.5

2,824.93,081.93,180.93,487.0

3,039.7

2,594.62,925.62,888.73,331.93,480.23,74s.5

3,337.218.83

31.0627.0533.6927.8828.5046.89

1,724.9

1,917,7

2,025.02,243.22,370.9

2,673.7

2,197.5

900.11,102.51,116.01,183.8

1,335.91,461.9

1,177.7

1,084.81,288.01,273.01,388.1

1,554.31 ,77i .2

1,363.4

1,346.01,535.21,607.51,775.5

1,935.3

2.181.7

7,761.3

1,703.61,919.5

2.038.22,226.9

2,364.12,8ss.0

2,182.4

2,087.62,263.52,417.02,648.32,807.23,102.5

2,6192

2,424.52,555.02,756.93,123,73,215.7

3,5S8.6

3,037.2

2,576.22,716.72,942.23,307.2

3,470,43,953.4

3,250.458.29

84n7974

6583

523

288

288

279

268

284255

1,629

561.2

808.3630.0465.0

8609725.7

701.3

70.31

B2.81

93.1166.88

95.S628.45

1,872.8

2,017.7

2,200.82,315.6

2,312.42>20.8

2,191.8

988.61,L?85.6

1,306.81,532.3

1,152.5I ,202.0

1,147.8

1,184.11,323.3

1,393.21,835.7

1,403.6

1,436.7

1,379.1

1,208.21,319.3

1,2EJJ.31.467.3

1,889.7

1,640.6

1,488.6

1,592.9

1,s47.3

2,024.8

1,643.6

2,058.2

1,721.5

1,415.11,738.0

1,543.01,888.7

2,040.1

2,062.6

1,861.31,988.6

2,152.22,363.5

2,248.4

2,552.0

2,138.1

1,747.6

2,038.1

2,137.42,171.3

2,542.02,5609

2/258.12,404.2

2,4S1 .62,830.0

2,76293,032.5

2,808.1

2,007,02,282.3

2,421.62,718.5

2*.O

3,046.7

2,572.82,792.4

2$77.4

2$27.1

3,146.5

3,387.4

3,069.1

2,358.52,721.82,?56.63,144.4

3,264.71,483.6

2,928.73,18&4

3,126.5

3,082.5

3,295.6

3,839.5

3,325.6

2,887.43,004.42.935.43,633.7

3,467.33.885.9

49.35

72

93113

84

77

84

281284

281

285

288253

487.6515.9

888.0748.7

888.1721.8

$6.6370.53

35.08

74.86}0.84

36.74

1.757.62,017.8

2,043.42,315.5

2,497.2

2,5S4.2

1,042.31,126.8

1,005.21,362.5

I ,477.7I ,482.0

NOTE: n = sample size, IV = estimated number of children in thousands, SD = standard deviation, SE~ = standard error of the mean, ~ = mean,

*U.S. GOVERNMENT PRINTING OFFICE 1977-260.937:39

43

I

“1

—

series 1.

series 2.

Series 3.

series 4.

VITAL AND HEALTH STATISTICS PUBLICATIONS SERIES

Formerly l%blu Health Senn”ce tiblication No. 1000

programs and Collection Rocedures. –Reports which des~be the general programs of the National

Center for Health Statistics and its offices and divisions, data collection methods used, definitions, andother material necessary for understanding the data.

Data Evaluation and Methods Research. –Studies of new statistical methodology including experimentaltests of new survey methods, studies of vital statistics collection methods, new analytical techniques,objective evaluations of reliability of collected data, contributions to statistical theory.

Analytical Studies. –Reports presenting analytical or interpretive studies based on vital and healthstatistics, carrying the analysis further than the expository types of reports in the other series.

Documents and Committee Reoorts. –Final reports of major committees concerned with vital andhealth statistics, and documen~ such as recommended model vital registration laws and revised birthand death certifkatez.

Series 10. Data from ~the Health Interview Survey. -Statistics on illness; accidental injuries; disability; use ofhospital, medical, dental, and other services; and other health-related topics, based on &ta collected ina continuing national household ihterview survey.

Series 11. Data J%om the Health Examzkation Survey .-Data from direct examination, testing, and measurementof national samples of the civilian, noninstitutionzlized popdation provide the basis for two types ofreports: (1) estimates of the medically defined prevalence of ipecific diseases in the United States andthe distributions of the popul~on with respect to physical, physiological, and psychological charac-teristics; and (2) analysis of relationships among the various measurements wi{hout reference to anexplicit finite univeme of persons.

Sera”es12. Data j%om the Institutionalized Population Surveys. –Discontinued effective 1975. Future reports fromthese surveys will be in Series 13.

Sert”es13. Data im Health Resources Utilization . –Statistics on the utilization of health manpower and facilities

provid~ long-term care, ambulatoq care, hospital care, and family planning services.

Ser12s 14. Data on Health Resources: Manpower and Facilities. –Statiztim on the numbers, geographic distrib-ution, and characteristics of health resources including physkians, dentisti, nurses, other health occu-

pations, hospitals, nursing homes, and outpatient facilities.

Sen”es20. Data on Mortality. –Various statistics on mortality other than as included in regular annual or monthlyreports. Special analyses by cause of death, age, and other demographic variables; geographic and timeseries analyses; and statistics on characteristics of deaths not available from the vital records, based onsample surveys of those records.

Series 21. Data on Ak?aIity, Mare-age, and Divorce. –Various statistia on natality, marriage, and divorce otherthan as included in regular annual or monthly reports. Special analyses by demographic variables;

geographic and time series analyses; studies of fertility; and statistics on characteristics of births notavailable from the vital records, baaed on sample surveys of those records.

Series 22. Data j%om the National Mortality and Natdity Surveys. –Discontinued effective 1975. Future reportsfrom these sample surveys based on vital records will be included in Series 20 and 21, respectively.

Series 23. Dab from the National Survey of Family Growth. –Statistia on fertility, family formation and diszo-Iution, family planning, and related maternal and infant health topics derived from a biennial survey ofa nationwide probability sample of ever-married women 1544 years of age.

, For a list of titles of reports published in these series, write to: Scientific and Technical Information Branch. National Center for Health Statistics

Public Health WIceHyattsville, Md. 20782