September 2000

A background paper prepared byRichard E. Hegner

The Asthma Epidemic:Prospects for Controlling

an Escalating PublicHealth Crisis

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Overview—After presenting a definition of asthma, thisbackground paper turns to a review of the epidemiologi-cal data that document the nature of the asthma epidemicin the United States. Next, the paper discusses healthresources utilization linked to asthma and identifies thesubpopulations that are most vulnerable to asthma. Abrief assessment of the mechanics of asthma and thechallenges of diagnosing the disease follows. Then thepaper examines the possible causes of asthma and theasthma epidemic, including indoor and outdoor environ-mental factors, allergies and possible changes in theimmune system, and new theories about the relationshipof asthma to overall advances in health care and eco-nomic development. After that, medical practice andhealth care coverage issues are explored, including theprogress made in asthma management, possible deficien-cies in physician practice, the state of patient informationabout asthma, poverty-related barriers to asthma diagno-sis and management, and the effects of health insurancepractices and the managed care revolution on asthma. Anexamination of the economic implications of asthma andpossible cost avoidances linked to better asthma manage-ment follows. The paper concludes with a discussion ofasthma and public health, including weaknesses incurrent surveillance for the disease, and a review of theplans of the Department of Health and Human Services(DHHS) for addressing asthma.

In a front-page article in the New York Times lastfall, a reporter observed, “The rapid rise in asthma, inthis country and in developed nations around the world,is one of the biggest mysteries in modern medicine.”1

Epidemiologic evidence suggests that she was notexaggerating. Data from the Centers for Disease Con-trol and Prevention (CDC) indicate that, between 1980and 1994, the self-reported prevalence rate for asthmain the United States jumped by 75 percent.2 Almost 6percent of all Americans now have asthma, which hasbecome the most common chronic illness amongAmerican children. While overall deaths from asthmaremain low—roughly 5,600 per year—asthma mortalityrates have more than doubled since the mid-1970s; thisis especially troubling given the consensus of profes-sionals that asthma deaths are largely preventable.

While science has not yet conclusively identified theroot cause of asthma or discovered the means to limitthe current epidemic, the medical technology to controlindividual cases of asthma exists. Indeed, the AmericanMedical Association (AMA) confidently declares, “Thecharacteristic symptoms of asthma . . . can be controlled.Nearly every person with asthma can expect to become

free of symptoms.”3 However, of special concern froma public policy perspective, available research indicatesthat asthma is a particular problem for poor inner-citychildren and for minority group members in general, asevidenced by their notably higher rates of hospitaliza-tion and use of emergency rooms for asthma treatment.While the incidence of asthma in these populations isnot strikingly higher than in middle-class Anglo popula-tions, asthma clearly affects Americans of color andindigent urban residents more seriously. In part, thisdifferential impact seems to reflect their poor access tomedical care of acceptable quality, since medicalprofessionals concur that hospitalization and emergencyroom treatment should not be part of routine care for thevast majority of asthmatics.

Indeed, the evidence is strong that a significantamount of medical resources are being expendedunnecessarily for urgent or emergent care for asthmathat could have been kept under control using readilyavailable therapies. To cite just one example, a recentstudy indicates that asthma is the third leading cause ofpreventable hospitalizations in the United States.4 Toput this in context, in absolute dollar terms, the totalannual costs of asthma in the United States wereestimated to be $11.3 billion in 1998, of which $7.5billion were direct medical expenses.5

Given its implications for health care spending in theUnited States, the asthma epidemic is receiving a greatdeal of attention as a public policy issue from both thepublic and the private sectors. Numerous federal agencies—most notably the National Institutes of Health (NIH),the CDC, and the Environmental Protection Agency(EPA)—state and local public health departments,individual practitioners and medical facilities, and healthplans are engaged in fighting asthma on a day-to-daybasis. Total Medicaid and Medicare expenditures forasthma treatment are estimated to exceed $1 billion. Thefederal government is investing more than $140 millionannually on asthma research. Yet critics have raisedquestions about whether public dollars are being investedwisely in the fight against asthma. While the nation hassome capacity to track asthma morbidity and mortality forthe population as a whole through surveys, it lacks data onasthma prevalence rates specific to states and localities—the front lines where most public health professionalscombat this epidemic.

BACKGROUND

In its authoritative Guidelines for the Diagnosis andTreatment of Asthma, the National Heart, Lung, and

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Blood Institute (NHLBI) in the National Institutes ofHealth (NIH) offered the following definition of thedisease:

Asthma is a chronic inflammatory disorder of theairways. . . . In susceptible individuals, this inflamma-tion causes recurrent episodes of wheezing, breath-lessness, chest tightness, and coughing, particularly atnight or in the early morning. These episodes areusually associated with widespread but variableairflow obstruction that is often reversible eitherspontaneously or with treatment. The inflammationalso causes an associated increase in the existingbronchial hyperresponsiveness to a variety of stimuli.6

In its Family Guide to Asthma and Allergies, theAmerican Lung Association (ALA) points out a defin-ing characteristic of asthma:

Much has been learned about asthma in recent years,but nothing is more important than the observationthat asthma is a disease of airway inflammation. Bythis physicians mean that people with asthma havechronically inflamed airways that are ever prone tobecome twitchy and constricted after exposure to anasthma trigger. It is as if the airways of people withasthma are lying in wait for trouble. They stay poisedat the edge of a cliff. . . . This means that asthma isboth a chronic and an episodic disease.7

There are two different forms of asthma. The first,known as allergic or extrinsic asthma, is characterized byattacks provoked by exposure to so-called asthma “trig-gers,” such as pet dander, second-hand tobacco smoke,dust mites, and mold spores. Typically, the onset of thisform of asthma occurs before the age 30; indeed, the vastmajority of childhood asthma is allergic. The secondform, nonallergic or intrinsic asthma, manifests itselfwith the same symptoms as allergic asthma; however,attacks of intrinsic asthma are not triggered by identifiableallergens. While intrinsic asthma can begin at any age, theonset typically occurs in adulthood.

THE ASTHMA EPIDEMIC—A LOOK AT THE STATISTICS

As noted above, the CDC estimates that the preva-lence of self-reported asthma among the general popu-lation of the United States jumped by 75 percentbetween 1980 and 1994. Figure 1 illustrates how theprevalence escalated over this period. One of theremarkable things about this escalation is that a substan-tial increase occurred among all racial and ethnicgroups, both genders, and all age groups, with somevariations in the rate of increase, which will be dis-cussed below.

The CDC estimates that asthma affected 14.6million Americans in 1996. This translates into about5.5 percent of the total population. (The comparablefigure for 1980 was about 3.0 percent.) In its recentreport, Attack Asthma, the Pew Commission on Envi-ronmental Health observes that about half of the casesof asthma in the United States today “are attributable tothe rising rates of asthma over the last 20 years.”8 Inother words, had the escalation in the prevalence ofasthma not taken place over the past two decades, onlyhalf as many Americans would be experiencing asthmatoday—in excess of 7 million fewer individuals.

Some might question whether the increased preva-lence of asthma can be appropriately characterized as “anepidemic.” One reason is that the term “epidemic” iscommonly understood to describe only infectious orcommunicable diseases, such as tuberculosis orHIV/AIDS. However, the term also encompasses non-communicable diseases such as asthma. Action AgainstAsthma, the strategic plan of the U.S. Department ofHealth and Human Services (DHHS), notes, “The steadyrise in the prevalence of asthma constitutes an epidemic,which by all indications is continuing.”9 In his often-citedDictionary of Epidemiology, John Last defines an epi-demic as “the occurrence in a community or region of

Figure 1Mean Rates of Self-Reported Asthma

U.S. Population, 1980–1994

Source: Centers for Disease Control and Prevention, 1998.Note: Rates are age-adjusted to the 1970 U.S. Population.

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cases of an illness . . . clearly in excess of normal expec-tancy.”10 Thus, the use of the term epidemic seems apt.

The asthma mortality rate has also undergone adramatic increase. From a low of 8.2 per millionAmericans between 1975 and 1978, the rate of asthmadeaths more than doubled to 17.9 per million for theperiod 1993 to 1995. As demonstrated in Figure 2,especially noteworthy is the fact that this escalationfollowed a dramatic decline of over 70 percent inasthma mortality rates from1960 to 1978. While thenumber of asthma deaths inthe United States—5,637in 1995—is relativelysmall in relation to otherdiseases, it translates intoabout 15.4 deaths fromasthma every day. Further-more, this trend clearlyseems to reflect deficien-cies in the delivery of treat-ment to asthma patients. Asecurities analyst who spe-cializes in health care ob-served in the New YorkTimes last fall, “Rightnow, asthma is the onlydisease category we coverwhere the death rate is ris-ing. . . . That proves thatthe disease is not beingtreated properly.”11

Looking at the nation’spublic health goals forasthma as articulated inHealthy People 2000 andHealthy People 2010, U.S.Surgeon General DavidSatcher observed, “Asthmais one of the areas wherewe are moving in thewrong direction.”

Trends in Levels ofHealth Resources Utilization

Both the asthma epidemic and the uncontrollednature of asthma in many cases are reflected in trendsin the levels of the utilization of hospital and otherhealth care resources for asthma patients. CDC dataindicate the following:

� From 1975 to 1995, estimated visits to physicians’offices for asthma more than doubled, from 4.6million to 10.4 million.12

� Between 1979-1980 and 1993-1994, the number ofhospitalizations for asthma increased from 386,000to 466,000—or by almost 21 percent.13

� The short-term trend data available for emergencyroom (ER) visits indicate that, for the three-year

period 1992 to 1995, there were no major changes inasthma-related ER visits. Nonetheless, asthma was thetenth most common principal diagnosis in ER visits in1996. (In the same year, asthma was the ninth mostfrequent diagnosis in hospital outpatient departments.)

Figure 2Asthma Death Rates, U.S. Population, 1960–1994

Source: Centers for Disease Control and Prevention.Note: Rates are age-adjusted to the 1970 U.S. Population.

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Asthma and Vulnerable Subpopulations

CDC data clearly show that, for a variety of reasons,a number of subpopulations of vulnerable Americans areat high risk of developing asthma and/or of sufferingfrom asthma that is poorly controlled. Among thesegroups are children, the elderly, racial and ethnic minori-ties, the indigent, people living in urban areas, women,and adults working in certain typically blue-collar jobs.

Asthma among Children. The escalation in theprevalence of asthma among children over the past twodecades has been noticeably greater than that amongadults. For children under age five, the increase inprevalence between 1980 and 1994 was 160 percent,while the corresponding increase for the generalpopulation was 75 percent. Although there are moreadult than child asthmatics, the prevalence of asthmaamong children is higher. Overall, the rate of self-reported asthma for children under 18 in 1995 was 7.5percent, as contrasted with 5.7 percent for the generalpopulation.

Asthma is the most common chronic disease amongchildren. Data from the AMA indicate that asthmaaccounts for more hospital and ER visits for childrenthan any other reason. Of all age cadres, asthma hospi-talization rates are highest for children under age five.(In 1993-94, 49.7 per 10,000 children age four andunder were hospitalized for asthma, as contrasted with18.1 per 10,000 for the population as a whole.)14

Asthma among the Elderly. Since there is no cure forasthma, it is a disease that many people carry with theminto old age, at which time, for a number of reasons, itscontrol is especially difficult. For one thing, bothasthma and other diseases with asthma-like symptomsare relatively common among older adults, increasingthe difficulty of diagnosis and proper treatment. Amongthe conditions of old age which are commonly con-founded with asthma are emphysema, bronchitis, andchronic obstructive pulmonary disease. Becausepolypharmacy—the simultaneous use of a number ofdifferent prescription drugs—is more common amongthe elderly, administering asthma medication to themsometimes presents special difficulties related topossible multiple drug interactions and contraindica-tions. Asthma mortality rates are also highest amongthe elderly, 89.8 per million in 1995, as contrasted with17.9 per million for the general population.

Asthma, Race, and Ethnicity. In 1995, the rate ofself-reported asthma for African Americans was 6.7percent, as contrasted with 5.6 percent for whites—nota large difference. Yet deaths from asthma are between

two and six times more likely to occur to AfricanAmericans and Hispanics than whites.15

Moreover, hospitalization rates for asthmatic AfricanAmericans are almost three times higher than those forwhites with asthma. The use of ERs by minorities forasthma care is also markedly higher. These utilizationstatistics and those for death rates clearly point to lesswell-controlled asthma among minorities.

Socioeconomic Status, Place of Residence, andAsthma. Clearly, Americans living in poverty face acomplex set of variables that predispose them to poorlycontrolled asthma. As the New York Times conciselyreported last fall,

The poor tend to have less access to regular medicalcare, are less able to afford the medications they needand are more likely to be around environmental“triggers” that set off asthma attacks. Also, someresearchers have found, families already under greatstress are less able to cope with the complicated dailyregimen that asthma demands.16

There are also a number of indications that theasthma epidemic has had a disproportionately heavyimpact on urban areas across the country—precisely theareas with some of the greatest concentrations ofpoverty. The Atlantic Monthly in May of this yearsingled out one of the five boroughs of New York Cityto report,17 “[In] the Bronx . . . rates of death from[asthma] are three times as high . . . as they are in theUnited States as a whole, and hospitalization rates arealmost five times as high. In some Bronx neighbor-hoods, 20 percent of the children have asthma.” TheNew York Times has referred to asthma as “the otherinner-city epidemic”—the first being HIV/AIDS.Testimony before the Senate Public Health Subcommit-tee last fall indicated, “More than 20 percent of U.S.asthma deaths in one year occurred in New York Cityand Chicago, even though these places had only 7percent of Americans with asthma.”18 Dramaticallyhigher asthma death rates also characterize a number ofother urban areas across the country.

Among the possible reasons suggested for theseemingly greater susceptibility to severe asthma ofAmericans living in urban areas—especially poor inner-city children—are greater exposure to outdoor airpollutants (especially diesel fuel fumes), less time spentoutdoors (partly because of concerns over crime),substandard housing (including poor ventilation,dampness, and infestation by pests, particularly cock-roaches), and greater reliance on hospitals for urgentand emergent care. The associate commissioner of theNew York City Department of Health voiced concern

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about a pervasive indifference to asthma control byurban parents: “Our major concern was that peoplewere accepting a level of symptoms as being ‘normal.’”

Asthma and Gender. Asthma is more common amongboys than girls but becomes more common amongwomen than men as people age. The most recent self-reported rates were 6.7 percent for women and 5.2percent for men. Between 1980 and 1994, asthma in-creased 92 percent among women but only 60 percentamong men. In the 1993 to 1995 period, asthma deathrates for women were slightly higher than those for men(20.0 per million versus 15.1 per million). Hospitalizationrates for asthma are also higher among women than men(20.0 versus 15.9 per 10,000 in 1993-94).

Occupational Asthma. Occupational asthma is charac-terized by development of the disease because of expo-sure to asthma sensitizers on the job. Since these sensitiz-ers generally include various types of chemicals, indus-trial and farm workers (particularly animal handlers) aremost likely to develop occupational asthma. The leadingwork-related lung disease, occupational asthma accountsfor at least 21 percent of adult-onset asthma.

ASTHMA AS A DISEASE ENTITYAsthma attacks—especially severe asthma attacks—

exact a heavy physical toll. Patients liken asthmaattacks to suffocating. Action Against Asthma featurestwo graphic descriptions of the experience:

� It’s a full body workout to take each breath. Mychest tightens up a lot and it either feels like I have1,000 pounds of bricks on my chest or that someonehas their hands on my lungs and is squeezing withall their might.

—An 18-year-old asthma sufferer

� It means that everyday events like soccer practice,visits with friends who have cats, and even hay ridesrequire vigilance. Most of all, it means a cough isnot just a cough. It can be the first cough in a longday and night punctuated every 10 seconds withanother sharp little cough.

—A young mother

Or, as the author of an article in May’s Atlantic Month-ly commented, “What the condition lacks in lethality,it more than makes up for in morbidity: it wears peopledown, crushes their spirits, and threatens their liveli-hoods.”

Noreen Clark, dean of the University of MichiganSchool of Public Health and a prominent researcher inasthma management, elaborates,

Patients and caretakers often become frustrated oreven angry because of the burdens that asthma im-poses. Episodes of symptoms can be frighteningevents. A study by our group of children’s asthmaattacks found that, during an attack, among low-income mothers of children with asthma, 62 percentfelt frightened, 33 percent felt desperate, and 44percent lacked the confidence to manage the attack.Learning how to cope with fear and anxiety is animportant part of patient education.19

The Mechanics of Asthma

Physiologically, there are three ways in whichasthma constricts the airways during an asthma attack:

� Tightening of the muscles encircling the airways,causing the airways to narrow—a phenomenoncalled bronchospasm.

� Inflammation of the airways, because of the entranceof fluid, blood cells, and irritating chemicals.

� Secretion of abnormal amounts of mucus, some-times forming what is called a “mucus plug,” whichfurther restricts the passage of air.

As noted above, however, asthma is a chronic condi-tion, and these acute manifestations of the disease areonly one element of what needs to be controlled ineffective asthma management.

There are gradations in the severity of asthma. Theserelate to variations in (a) the severity of the chronicdisease, (b) the gravity of acute attacks, and (c) bothfactors over time in an individual.

Diagnostic Challenges

Asthma is often difficult to diagnose. As a result, itis frequently undiagnosed or misdiagnosed. The AMAitself concedes, “Part of the problem lies with doctorswho do not keep up with developments in the field ofasthma; they may misread asthma symptoms or cling tooutdated or inaccurate information.”

But there are several inherent features of the diseasewhich make its diagnosis especially challenging. For onething, because the disease is both episodic and chronic,diagnosis has a lot to do with timing of patient visits toproviders. Symptoms that may be quite evident when anappointment was made may have subsided by the time apractitioner examines a patient. Secondly, asthma isfrequently confused with other chronic disorders, such asemphysema, bronchitis, heart disease, cystic fibrosis, andchronic obstructive pulmonary disease. (There is onebasic difference, however—most of the airway obstruc-tion caused by asthma can be reversed with medication.)

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Diagnosis of asthma in children under age six orseven is fraught with particular difficulties. Such youngchildren often have special difficulty in followingdirections about the use of equipment to measure lungfunction, which requires them to exhale continuously attheir utmost capacity.

Finally, symptoms vary among patients. For exam-ple, while wheezing is thought to be a general charac-teristic of asthma, not all asthmatics wheeze. It is forreasons like this that the Institute of Medicine (IOM)concluded in its recent report on asthma and indoor airexposures, “These findings raise the question of wheth-er asthma is best thought of as a single disease entity,a syndrome, or a final common manifestation of severaldifferent disease processes.”20

POSSIBLE CAUSES OF ASTHMA ANDTHE EPIDEMIC

There are at least three fundamental questions aboutasthma and the public’s health. First, what causesasthma? Second, what has caused the sharp escalationin the prevalence of asthma? Third, what causes theexacerbation of asthma symptoms in some people?Unfortunately, there are no conclusive answers to eitherof the first two questions; at best, there is suggestiveevidence. However, a great deal is known about whatexacerbates symptoms for some asthmatics, how thosesymptoms can be controlled on a short-term basis, andhow asthma can be managed to prevent symptoms fromoccurring over time.

With respect to the first question, the recent IOMreport concluded, “No single agent or factor has yetbeen identified as a necessary or sufficient cause ofasthma.” Reflecting on the asthma epidemic, Satchercommented, “Until you understand why you have anincrease, and you have documented it, it is very hard tosay you have a strategy that is going to make a differ-ence.” The Pew Commission on Environmental Healthsuccinctly described the state of current science:“While little is known about the factors that causeasthma to develop (and even less about why prevalencerates are going up), more is known about the factorsthat cause exacerbation of asthma.”

Genetic Factors

For some time now, there has been widespreadspeculation that genetic factors predispose someindividuals to asthma. But until very recently, discus-sion of genetic influences on asthma have remainedlargely conjectural. The IOM could at best conclude:

Most scientists believe that some individuals have aprior underlying predisposition that permits the evolu-tion of clinical asthma. The development of this predis-position to asthma is dependent on a complex—and atpresent poorly understood—combination of factors,which are partially inherited and partially acquired laterin life. [However,] genetic influence . . . explains only30-80 percent of the asthma risk. The remaining riskseems to be related to environmental exposure.

As in so many areas of medicine, recent geneticresearch holds promise for unlocking some of themysteries of asthma. In June 1999, the AmericanJournal of Public Health ran an editorial that reported,

Research focused on gene-environmental interactionsholds great promise in treating, managing, and ulti-mately curing or preventing asthma. . . . Substantialevidence exists for linking several chromosomalregions with the development of asthma. . . . Many ofthese areas contain genes whose functions may beimportant to the development of airway inflammationand asthma. Candidate genes . . . that may be impor-tant to the pathophysiology of asthma are currentlybeing selected and examined.21

Environmental Factors

Despite the promising research on genetic causation ofasthma, there is consensus that the human genome couldnot possibly have changed so radically over recentdecades as to explain the escalation of asthma morbidityand mortality over that period. Since there is also generalagreement that some combination of genetic and environ-mental factors eventuates in individual cases of asthma, anumber of observers have induced that some sort ofdramatic change in the indoor and/or outdoor environ-ments lies at the root of the asthma epidemic.

Discussing the interrelationship of the immune systemand the environment in asthma, the AMA’s EssentialGuide to Asthma notes, “In asthma, the immune systemoverreacts to elements in the environment.” Or, as thePew Environmental Health Commission expresses it,“Genetics loads the gun [through its effects on the im-mune system] . . . but environment pulls the trigger.”

After its exhaustive review of indoor air particulatesthat might cause asthma, the IOM was compelled toconclude, “We still do not know whether or to whatextent the reported increases in asthma can be attributedto indoor exposures.”22 However, they reached threestrong positive conclusions, namely that there is suffi-cient evidence of causal relationships between thefollowing:

� Exposure to house dust mite allergen and the devel-opment of asthma in susceptible children.

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� Exposure to the allergens produced by cats, cock-roaches, and house dust mites and exacerbation ofasthma in sensitized individuals.

� Environment tobacco smoke exposure and exacer-bations of asthma in preschool-aged children.

There is limited evidence that exposure to some ofthese factors may have increased over the past fewdecades. For example, it is known that dust mites thrivein indoor environments where air does not circulate.Since the energy crisis of the 1970s, much residentialand office building construction has emphasized energyconservation; in general, this means many buildingswithout windows that open and/or a degree of insula-tion that allows little air to circulate from the outside.The AMA reports that the number of household pets ison the rise. It is estimated that around 28 percent ofU.S. households have cats. The IOM report suggeststhat one means of reducing risks of asthma exacerba-tions is to remove cats from the homes of asthmatics.There is also general evidence that people in advancedindustrial countries like the United States are spendingincreasing time indoors, thus elevating the exposure ofsusceptible individuals to those indoor agents thatmight cause or exacerbate asthma.

No study has been done of the influence of outdoor airquality on asthma that approximates the recent IOM studyin either scope or size. Many observers point to the factthat air quality has been generally improving in recentyears as a reason that outdoor air pollution has probablynot contributed to the asthma epidemic. However, thereis some speculation that the increased usage of diesel fuelmay have contributed in some as-yet-to-be-determinedmanner to the upsurge in asthma, especially in urbanareas.23 The NHLBI Guidelines for the Diagnosis andTreatment of Asthma cautions about outdoor air pollutionas a cause of asthma exacerbations: “Increased airpollution of respirable particulates, ozone, SO2 [sulfurdioxide], and NO2 [nitrogen dioxide] have been reportedto precipitate asthma symptoms and increase emergencydepartment visits and hospitalizations for asthma.”

Asthma, Allergies, and the Immune System

Some asthma seems to be rooted in a malfunction-ing immune system that overreacts to benign sub-stances in the environment. A British discussion of theasthma epidemic explains this phenomenon as follows:

We all have an immune system which is similar to adefensive army, and this protects us from a hugerange of insults which our environment is inclined tothrow at us. These include bacteria, viruses, fungi,

yeasts, toxins, and allergens. The prime function ofthe immune system is to distinguish between invadersthat may be harmful from those that are harmless.Thus the immune system should act effectivelyagainst microbes which may cause disease, but notreact against harmless items such as pollen, dust, dustmite and food molecules.24

Yet it is precisely such “harmless items” that precipitateasthma attacks among those with allergic asthma. Ingeneral, allergic reactions are caused by changes orabnormalities in the immune system—hence, themedical subspecialty of allergy and immunology.

“Does Civilization Cause Asthma?”

Last May’s Atlantic Monthly article on asthma sumsup one recent school of thought about the asthmaepidemic:

A number of specialists . . . believe that modern lifemay be responsible for the developed world’s asthmarates—but in a very unexpected way. [They] believe ...modern hygiene practices and antibiotics . . . foreclosethe need for the young immune system to tacklemicrobial and parasitic challenges. . . . This couldexplain why children in the developing world, whoare repeatedly infected by bacteria and parasites, areunlikely to contract asthma, whereas children in thedeveloped world, who are inoculated against infec-tious diseases and frequently given antibiotics, arecontracting asthma in ever greater numbers.

Related variations of this theory are that children aregetting less healthy outdoor exercise—what might becalled the “couch potato corollary”—that the migrationof people from rural to urban areas has reduced theirexposure to organic factors that strengthen the immunesystem, and that the widespread use of antibiotics, whilereducing the incidence of some infections, may becontributing to the upsurge in asthma by retarding thedevelopment of immune responses.

These theories are still highly conjectural at this stage.Research is currently under way to test these hypotheses.25

MEDICAL PRACTICE AND HEALTHCARE COVERAGE ISSUES

Nevertheless, despite the somewhat rudimentary stageof the knowledge about the etiology of asthma and thereasons for the current epidemic, there seems to beconsensus that all but the most severe cases of asthma canbe controlled and that almost every American with asthmacan enjoy a life largely free of symptoms. Yet there aretroublesome signs that the health care delivery system isnot keeping up with the epidemic, with attendant costs for

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both the national economy and for asthmatics themselves.As Michael Rich, a pediatrician and child health re-searcher at Harvard Medical School, remarked, “Billionsof dollars are being spent on [asthma], and we know a lotabout it, yet it’s getting worse, because we’re not askingthe right questions. The real question is, what stands inthe way of knowledge being translated into behavior?”26

Changing Science and Changing TherapiesThere has been continued progress in developing

new asthma therapies—particularly pharmaceuticalsand devices—both making the control of asthma fareasier and reducing possible side effects. Unfortu-nately, for a number of reasons, these therapies are notbeing made available to all Americans with asthma.

One prominent researcher has likened the introduc-tion of inhaled steroids for asthma to the discovery ofpenicillin: “It turned treatment of asthma around com-pletely.” Corticosteroids were first prescribed forasthma patients in the 1960s and have proven veryeffective in long-term asthma control. In the early1980s, steroid inhalers were first introduced—a majortechnological advance that targeted the lungs with thedrug, pumped less of it into the rest of the body, andmade daily use easier. The ALA declares, “Gone aremany of the side effects and cumbersome deliverydevices that complicated early asthma medications.”

In essence, corticosteroids suppress the activity ofimmune system cells that release inflammatory chemi-cals. It was not until the 1990s, however, that thesalience of inflammation as a factor in asthma attackswas fully appreciated and the key role of cortico-steroids in suppressing inflammation was completelyunderstood. Furthermore, a significant problem withthese drugs—which should not be confused withanabolic steroids, the controversial drugs used by someathletes—is their potential long-term side effects,which include growth retardation (obviously a specialconcern for pediatric patients), glaucoma, hypertension,and osteoporosis.

Another important development has been the formula-tion and issuance of national clinical practice guidelinesfor asthma. In 1991, following a process of broad consul-tation with experts in the field, the National AsthmaEducation and Prevention Program (NAEPP) in theNHLBI released its Guidelines for the Diagnosis andManagement of Asthma, which translate advances in thescientific understanding of asthma—particularly the roleof chronic inflammation—into practical recommenda-tions for controlling persistent asthma. An updatededition of the guidelines was issued in 1997.

The NAEPP/NHLBI guidelines establish a numberof goals for asthma therapy:

� Preventing chronic and troublesome symptoms.

� Maintaining (near) “normal” pulmonary function.

� Maintaining normal activity levels (including exer-cise and other physical activity).

� Preventing recurrent exacerbations of asthma andminimizing the need for emergency departmentvisits or hospitalizations.

� Providing optimal pharmacotherapy with minimal orno adverse effects.

� Meeting patients’ and families’ expectations of andsatisfaction with asthma care.

The guidelines proceed to offer health care professionalsdetailed advice on how best to meet these goals. Theystress the importance of teaching asthma self-manage-ment and prevention to patients and underscore the keyrole of the partnership between patients and physicians.

The most recent edition of the guidelines is 146pages long and quite detailed. To make their contentmore accessible to practitioners, the NAEPP has issueda more convenient Practical Guide for the Diagnosisand Management of Asthma, which is published in alarger print, bulleted format and totals only 52 pages.27

Deficient Medical Practice

A number of sources speculate that primary carephysicians may not be as knowledgeable about asthma oras up-to-date as they should be about advances in asthmatreatment. For example, the DHHS strategic plan, ActionAgainst Asthma, suggests, “Recent evidence indicatesthat many health care providers do not follow the Guide-lines for the diagnosis and treatment of asthma. Failure tofollow clinical guidelines stems in part from factorsrelated to knowledge, attitudes, and behavior.”

There is also general concern that many physiciansare addressing asthma on only a short-term, palliativebasis. That is, they are helping patients address asthmaattacks without getting at the underlying diseasethrough a course of long-term therapy. May’s AtlanticMonthly asserts, “Some physicians are unaware thatasthma is a chronic disease requiring constant vigilance....Many doctors seem to be prescribing drugs to curtailasthma episodes rather than caring for the patient whosuffers them.”

Problems in primary care physician relationshipswith their asthmatic patients seem to be underscored by

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statistics cited at the Senate Public Health Subcommit-tee hearings on child health last fall:

More than 90 percent of children who present to theemergency department with an asthma attack have aprimary care provider. Despite this, two-thirds godirectly to the emergency department when havingproblems with their asthma and one-third rely on theemergency department for all of their asthma medica-tions.28

Furthermore, financial pressures may in someinstances be undercutting the ability of physicians toinvest the amount of time in patient education neededby asthmatics. One physician observed,

When I first see a patient [who has asthma], I spendan hour with him. . . . I can do this because I’m anacademic physician who gets paid by the year, not bythe patient. A general pediatrician working undermanaged care has to see four to six patients anhour—he doesn’t have the time to talk about diet,exercise, the kid’s environment. And that’s why thesekids keep ending up in the ER.

Finally, there is speculation that some physiciansmay not be as up-to-date on current asthma medicationsas they should. The AMA Essential Guide to Asthmaemphasizes,

Different medications with serious side effects areintroduced each year. New studies document asthmatriggers and evaluate drug reactions. Your doctor needsup-to-date expertise to integrate this information intothe long-term program that works best for you.

Confused, Uninformed, or NoncompliantPatients

A number of observers emphasize the difficultypatients experience in adapting to an asthma treatmentregimen. For severe asthma, some have likened thecomplexity of therapies to those for treating HIV/AIDS. Yet even treatment for routine asthma can beburdensome. A prominent physician-researcher ob-served to a New York Times reporter,

Asthma takes a lot of work. . . . You have to take dailymedication, at fixed intervals, and sometimes inresponse to changes in symptoms. And inhalers arefundamentally unpleasant devices. Many patientshave at least two inhalers that have to be taken atdifferent times. The more you ask patients to do, theless they do.

He went on to express concern that many patients andparents do not get appropriate guidance on how to treatthe disease: “They’re just handed a prescription and toldto use it, without an in-depth explanation of thedisease.”29

Noreen Clark underscores the crucial role of patientjudgment in the management of asthma:

Asthma management requires a high degree of judg-ment on the part of the patient. There is no absoluterecipe for successful control. Sometimes asthmasymptoms are predictable and sometimes they are not.A patient needs to be highly self-regulating, that is,have the ability to observe, judge, and act on the basisof subtle changes in symptoms or peak flow [respira-tory] values or functional status. It may be that devel-oping skills of self-regulation is more important thanlearning asthma facts.

Patients who experience symptoms more than twice aweek generally need two different types of drugs, a “long-term control medication” that suppresses inflammationover a lengthy period (for example, a corticosteroid) aswell as a “quick-relief medication” that opens airways andfacilitates breathing when an asthma attack occurs.Getting patients to adhere to this treatment regimen—especially indigent patients who lack adequate third-partycoverage—has proven difficult. Many patients tend torely solely on the “quick-relief” drug.

The Washington Post reports that fewer than 20percent of Americans with asthma use anti-inflammatorie-s, as contrasted with 65 percent of asthmatics in Europe.In general, physician failure to prescribe the medicationseems to be at the root of the problem. However, patientnonadherence to prescriptions may also play a role.According to a physician at the Institute for Asthma andAllergy at the Washington Hospital Center,

Corticosteroids don’t make you feel better immedi-ately. The emergency medicine makes you feel betterbut doesn’t address the underlying problem. . . . [As aresult,] the most important medicine is the one peoplefeel they don’t need, so they stop taking it and get intotrouble.30

Action Against Asthma declares without qualification,“Effective medical management and patient educationreduces the use of emergency services and improvesquality of life.” Thus, the bottom line issue appears tobe in part how to promote effective patient education.

Poverty-Related Barriers to Diagnosis andManagement of Asthma

At its hearing last fall, the Senate Public HealthSubcommittee was informed about a basic complex ofobstacles to patient compliance: “Poverty, single parentfamilies, and multiple caregivers are major barriers toadherence with complex chronic treatment regimens.”A physician who practices in a low-income section ofWashington, D.C., expressed the same thought somewhat differently: “To manage asthma well you need a

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functioning medical system, society, and family.” AWashington Post reporter observes, “Good care is acumbersome, labor-intensive, costly process—which iswhy so many financially hard-pressed families end updoing little or nothing until a crisis hits and they mustrush their kids to the emergency room.” Even suchstructural barriers as deficient or inconvenient publictransportation systems contribute to impeding access bypoor families to needed ongoing asthma care.

But the problem seems tied to something more basicthan any of these poverty-related variables. Access tomedical care of acceptable quality is a basic problemfor indigent patients. Irwin Redlener, M.D., presidentof the Children’s Hospital at Montefiore MedicalCenter in the Bronx points out,

If you cannot at the end of the day provide the medi-cal care that you have educated people about, youhave only completed half the bargain and you end upwith some very frustrated families. . . . We havepatients coming to us who have learned from thepublic education campaign who say to us, ‘But weneed a doctor.’

The end results are evident in one study of asthma carein New York City, which found that there were 223 ERvisits for asthma for every 10,000 Spanish Harlemresidents, while certain wealthy lower Manhattandistricts had no ER visits for this problem.31

Health Insurance Practices and theManaged Care Revolution

This year, the Administration for Healthcare Researchand Quality (AHRQ) issued a study indicating that in1996 about 78,000 hospital admissions for asthma amongchildren were covered by Medicaid, 68,000 admissionswere paid for by private insurance, and 8,000 childrenwithout insurance were admitted for asthma. Hospitaladmissions for asthma were proportionately lower forchildren with private insurance than for either childrenwith Medicaid or uninsured children—2.1 percent, 3.2percent, and 2.6 percent, respectively.32

Even those who have private insurance coverage facecertain barriers to care for their asthma, including restric-tions on the number or length of preventive or follow-upvisits, limits on reimbursements, and lack of coverage forpatient education or case management. The obstaclesfaced by those covered by managed care may be evenmore challenging, insofar as they relate to gatekeepingrequirements and limits on provider panels.

For routine cases of asthma, most primary physiciansshould be able to treat patients appropriately. (As noted

above, this supposes that they are both knowledgeableand not confronted by productivity constraints thatprevent them from spending adequate time with asthmaticpatients.) However, for more severe cases of asthma,treatment by experienced providers—or in some cases,specialists such as pulmonologists or allergists—isnecessary. Insofar as managed care physician panels lacksufficient numbers of such experienced providers orspecialists, or if managed care gatekeeping impedes theaccess of severely asthmatic patients to such providers,managed care poses an obstacle to acceptable qualityasthma care. Similarly, some managed care plans maysteer patients with serious asthma away from tertiary carehospitals because of perceived higher costs.

On the other hand, managed care holds significantpromise for asthma treatment. Along with diabetes,asthma has been singled out by a number of managedcare organizations (MCOs) for special disease manage-ment initiatives. This is partly because of the dividendsto health plans’ case management initiatives from evenrelatively short-term interventions to prevent asthmaattacks from escalating to the point of a need foremergency care. By offering asthmatics a “medicalhome” with continuity of care, managed care can alsomake an important contribution to controlling asthma.

Furthermore, the National Committee for QualityAssurance (NCQA), an accrediting organization whoseproclaimed mission is “to evaluate and report on thequality of the nation’s managed care organizations,” hasincorporated an asthma measure in its most recentedition of HEDIS (the Health Plan Employer Data andInformation Set), its performance measurement tool forMCOs. This new asthma indicator, “AppropriateMedications for People with Asthma,” measures thepercentage of MCO members with asthma who receivemedications recommended as primary therapy for long-term control of the disease, including inhaled cortico-steroids. (NCQA explains that addition of anotherproposed HEDIS asthma measure, “Emergency RoomVisits for People with Asthma,” was “postponed due totechnical considerations.”)

ECONOMIC IMPLICATIONS OFASTHMA

Testimony presented to the Senate Public HealthSubcommittee last fall indicates:

More than 80 percent of the total direct costs ofasthma result from the 20 percent of the asthmapatients who have significantly greater morbiditymeasures and who are readily identifiable as the

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highest users of hospital-based asthma services. In1990, nearly half of all asthma health care costs weredue to severe illness consequences such as hospital-izations and emergency room visits.33

This evidence suggests the possible merits of targetingasthma cost-containment efforts on the minority ofhigh-cost patients.

Direct and Indirect Costs

An analysis done of medical expenditures for asthmain 1990 indicates that the estimated $3.64 billion in directcosts were broken down approximately as follows:34

� Inpatient hospitalization, 43 percent.

� Prescription medications, 30 percent.

� Physician-related services, 14 percent.

� ER visits, 8 percent.

� Outpatient hospital visits, 5 percent.

This evidence suggests that asthma cost containmentefforts ought to focus on inpatient hospitalization,prescription drugs, and ER visits, assuming that physi-cian services and hospital outpatient care are for themost part necessary and efficiently delivered.

Of the estimated $11.3 billion total costs of asthmain 1998, $3.8 billion, or roughly 34 percent, were cal-culated to be indirect costs. These indirect costs in-cluded lost work time, missed school days, and limita-tions on daily activity. Healthy People 2010 indicatesthat 19.5 percent of people with asthma in the period1994 to 1996 had activity limitations. It also points outthat asthma ranks as the fourth most common chroniccondition in the United States.

It is estimated that children with asthma miss threetimes as many school days as their classmates without thedisease. A school director from East Harlem character-izes asthma as “an assault on the children” and describesthe consequences for their education: “The time that islost from the classroom, you can’t recover that time. . . .With kids that are coming in with several strikes againstthem to begin with, this just complicates matters.”

Potential Cost Avoidances

No one appears to have developed an estimate ofhow much might be saved if asthma in the UnitedStates were truly under control—if the disease werebeing optimally diagnosed and managed in keepingwith available guidelines and technology. However,using the percentages cited above, it is at least concep-

tually possible to estimate that eliminating unnecessaryemergency room visits and inpatient hospitalizations islikely to save billions of dollars. Obviously, there wouldbe additional savings in such indirect costs as reducedproductivity and lost school and work days, as well asadded years of life for those who would otherwise dieas a result of asthma.

One of the physicians testifying before the Senatechild health hearing last fall pointed out,

Approximately 50 percent of the economic impact [ofasthma] is associated with emergency departmentvisits, hospitalization, and death—in other words,expenditures related to asthma exacerbations ratherthan the management of chronic stable asthma.35

The AMA Essential Guide to Asthma notes, “The keyto living a healthy life with asthma appears to bepreventing emergencies; a comprehensive medical planalong with monitoring of the person’s condition are thekeys to stopping asthma attacks before they start.” Thesame observation might be made about the centrality ofpreventing emergencies to avoiding unnecessary costsof asthma. The interventions needed to prevent asthmaemergencies are spelled out in the NAEPP’s asthmaguidelines.

Here again, effective patient education is a linchpinof successful asthma management. Clark points out,

Outcomes achieved through well-conceptualized andwell-delivered patient education have been shown toinclude reductions in school absences and use ofemergency department and hospital services, increasesin patient self-efficacy, and use of asthma-manage-ment strategies, less frequent wheezing, and improvedacademic performance.

ASTHMA AND PUBLIC HEALTH INTHE UNITED STATES

There are a number of different reasons why asthmawarrants the attention of health policymakers at alllevels of government. Among these are the overall costsof treating the disease; the effects on citizens’ lives,education, and incomes; the promise of availabletherapies and patient and provider education for reduc-ing these costs; and the practices of third-party payersthat may result in inefficient and/or inappropriateasthma coverage limitations.

Surveillance for Asthma

One of many impediments to developing a coherentnational asthma strategy is the highly-decentralized

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nature of the nation’s public health system. The loci ofmost of the nation’s public health activity related toasthma and many other major diseases are state andlocal (primarily county) governments. As might beexpected, given such a large element of state and localcontrol, the capacity of the public health system toconfront a challenge like the asthma epidemic isextremely uneven. Local health departments vary fromstorefront operations with a staff of only a few profes-sionals in rural areas to large, complex bureaucracieslike those in New York and Los Angeles.

A related problem is that surveillance is largely amatter of state volition. Because epidemics like asthmaare no respecters of state boundaries, this yields apublic health dilemma—states with aggressive surveil-lance systems for asthma and other diseases may findthe effectiveness of their efforts compromised byneighboring states that choose not to engage in surveil-lance. This problem is especially likely to affect multi-state metropolitan areas.

It is therefore not surprising that one of the majorfactors standing in the way of a national asthma strategyis the lack of a strong surveillance system to trackchanges in the prevalence of asthma at the subnationallevel. While a number of other diseases are reportedthrough state and local health departments to the CDC,which tracks trends in these diseases and reports themback to state and local governments, no such systemexists for asthma. A 1996 CDC survey showed that 27states had no ongoing asthma monitoring or trackingsystems.

Satcher has stated, “In public health, we can’t doanything without surveillance. . . . That’s where publichealth begins.” Indeed, one of the basic principles ofpublic health is that “to measure is to get it done.” If apublic health agency does not know the specifics ofwhat it is tracking, it cannot measure the progress it hasmade. To employ a mixed metaphor used by Health-Track, a Georgetown University environmental healthproject, in its recent report on asthma surveillance, “Inour fight against asthma, we have given public healthprofessionals not radar, but a blindfold, and then askedthem to perform like a circus knife-thrower.”36

Most indications are that the costs of putting anational asthma surveillance system in place would bemore than offset by the savings resulting from bettercontrol of the disease. Among the very real impedi-ments to implementing such a system, however, are thedemands it would place on physicians, hospitals, andother health care providers to report asthma cases.

DHHS Strategic Plans and Asthma

Asthma is a major focal point for Healthy People2010, the federal government’s strategic public healthplan for the next ten years. The plan has eight goalsrelated to asthma, among them sizable reductions in therates of asthma-related deaths, hospitalizations, and ERvisits. Somewhat more nebulous are goals related toreducing the rate of activity limitations among peoplewith asthma and increasing the ratio of people withasthma who receive patient education. Labeled “develop-mental” are goals addressing reduction in the number ofmissed school or work days, increasing the proportion ofpeople with asthma who receive care in accordance withthe NAEPP guidelines, and establishing a surveillancesystem for tracking asthma in at least 15 states, whichwould include data on asthma deaths, rates of illness,levels of disability, and the impact of occupational andenvironmental factors on asthma. (The goals designated“developmental” are contingent on the development ofdata sources.)

Healthy People 2000 also had three asthma-relatedobjectives: (a) a reduction in asthma hospitalizationsfrom 188 per 100,000 in 1987 to no more than 160 per100,000 in 2000, (b) a reduction in activity limitationsamong people with asthma from 19.4 percent in 1986-1988 to 10 percent, and (c) a general increase in theproportion of people with chronic and disabling condi-tions who receive patient education from a baseline of9 percent in 1991 to 50 percent in 2000. Limitedprogress was reported in increased patient educationrates, while the rates of hospitalization and limitationson activity both increased—in part, perhaps, because ofthe increased prevalence of asthma.

Action Against Asthma, the DHHS strategic planissued in May 2000, identifies four relatively broad“priorities for investment”:

� Determine the causes of asthma and develop inter-ventions to prevent its onset.

� Reduce the burden of asthma for people living withthe disease.

� Eliminate the disproportionate burden of asthma inminority populations and those living in poverty.

� Track the disease and assess the effectiveness ofasthma programs.

These sweeping, rather all-encompassing prioritiesfrom Action Against Asthma seem to complement themore specific, quantified goals set forth in HealthyPeople 2000 and Healthy People 2010.

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1. Sheryl Gay Stolberg, “Poor People Are Fighting BafflingSurge in Asthma,” New York Times, October 18, 1999, A1,A18.

2. David M.. Mannino et al., “Surveillance for Asthma—United States, 1960-1995,” Morbidity and Mortality WeeklyReport, 47 (April 24, 1998), SS-1, 1-30. In the executivesummary of its recent report, Clearing the Air: Asthma andIndoor Air Exposures, the Institute of Medicine notes: “Theprevalence of asthma in some other parts of the world—including Australia, New Zealand, Ireland, and the UnitedKingdom—exceeds that of the United States.”

3. American Medical Association. Essential Guide toAsthma (New York: Pocket Books, 1998), 1.

4. G. Pappas et al., “Potentially Avoidable Hospitalizations:Inequalities in Rates between U.S. Socioeconomic Groups,”American Journal of Public Health, 87 (1997): 811-16.

5. National Health, Lung, and Blood Institute, Morbidity andMortality: 1998 Chartbook on Cardiovascular, Lung andBlood Diseases (Bethesda, Md.: National Institutes of Health,October 1998).

6. National Heart, Lung, and Blood Institute, Guidelines forthe Diagnosis and Management of Asthma, Expert PanelReport 2, Clinical Practice Guidelines, NIH Publication 97-4051 (Bethesda, Md.: National Institutes of Health, July1997), 8.

7. American Lung Association Asthma Advisory Group withNorman H. Edelman, Family Guide to Asthma and Allergies(Boston: Little, Brown, and Co., 1997), 11.

8. Pew Environmental Health Commission, “Attack Asthma:Why America Needs a Public Health Defense System toBattle Asthma Threats,” Baltimore, 1999, 10; accessed June30, 2000, at http://www.pewenvirohealth.jhsph.edu.

9. U.S. Department of Health and Human Services, ActionAgainst Asthma, Department of Health and Human Services,Washington, D.C., May 2000, 1; also available athttp://aspe.hhs.gov/sp/asthma.

10. John M. Last, A Dictionary of Epidemiology (New York:Oxford University Press, 1995).

11. David J. Morrow, “New Treatments Lag in FightingAsthma,” New York Times, October 19, 1999, D5.

12. Repeat visits could not be netted out from these totals, sothe number of individual patients involved could not bedetermined. Furthermore, while it may be assumed that mostof these ambulatory visits were for appropriate reasons, somemay have been urgent visits for uncontrolled asthma thatmight have been unnecessary if the patients’ asthma had beenunder control.

13. Again, there is no way of determining how many individ-ual asthma patients were involved. However, with inpatienthospitalization, it can be assumed that a sizable numberentailed admissions for uncontrolled asthma that might havebeen handled on an ambulatory basis if intervention hadoccurred early enough. Nevertheless, in light of the concur-rent increase in the prevalence of asthma—which increasedby about 75 percent over the same period—the rate ofhospitalizations across the asthmatic population has actually

WHAT DO CURRENT TRENDSPORTEND?

In its report on asthma last year, the Pew Commissionon Environmental Health projected a rather bleak scenein the face of no substantial change in public policy:

By the end of this decade, if no action is taken toreverse this trend and it continues its current pace, theCommission calculates that 22 million Americans willsuffer from asthma—eight million more than at present.That’s one in 14 Americans and one in every fivefamilies forced to live with the disease. By 2020, theCommission estimates that the number could increaseto 29 million—more than twice the current number.

In response to these projections, the commissionrecommends a set of ambitious goals, including cuttingthe number of asthma cases in half by 2020; imple-menting a national surveillance system within fiveyears; investing the surgeon general with line authorityto oversee all federal asthma efforts; instituting asystem within one year at CDC that would track andinvestigate every asthma death in the country; andestablishing a comprehensive public education cam-paign on asthma within two years.

Yet there is reason to question the short-termfeasibility of not just these recommendations, but alsothose of DHHS. Last year’s Senate hearing on childhealth heard testimony from a leading authority aboutjust what currently can be done about asthma:

We currently do not have the basic knowledge neededto prevent asthma. What we do now have is theknowledge to prevent the major impact of asthma onchildren; the knowledge to prevent deaths, frequenthospital admissions and emergency room visits,school absences, and prevent other adverse conse-quences of poorly controlled asthma such as lack ofparticipation in school physical education and sports.Thanks to efforts of the [NAEPP], we have guidelineson how childhood asthma should be treated. We haveeffective medications, and we know what childrencan do to reduce the burden of asthma on their lives.37

While the testimony addresses asthma among children,the points made in it seem equally applicable to thenation’s capacity to address asthma among the adultpopulation.

ENDNOTES

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declined over this period.

14. With respect to childhood asthma being treated on anambulatory basis, the New York Times notes, “Asthma hasbecome so prevalent that some states, including New York,have begun passing laws allowing children to carry themedication with a doctor’s permission, bypassing the usualrequirements that drugs be administered by a nurse.” In manystates where such legislation has not been enacted, childadvocates are working for its passage.

15. It is important to note, however, that the Hispanicpopulation is hardly homogeneous in its experience withasthma. Asthma morbidity and mortality tend to be higheramong Puerto Ricans than among Mexican-Americans orCubans. See David M. Homa, David M. Mannino, andMarielena Lara, “Asthma Mortality in U.S. Hispanics ofMexican, Puerto Rican, and Cuban Heritage,” AmericanJournal of Respiratory Critical Care Medicine, 161 (2000):504-509. See also Marielena Lara et al., “Elevated AsthmaMorbidity in Puerto Rican Children: A Review of PossibleRisk and Prognostic Factors,” Western Journal of Medicine,170:2 (2000), 75-84.

16. Stolberg, “Poor People.”

17. Ellen Ruppel Shell, “Does Civilization Cause Asthma?”Atlantic Monthly, May 2000.

18. Carlos Camargo, M.D., Dr.P.H., Department of Emer-gency Medicine, Massachusetts General Hospital, andresearch epidemiologist, Harvard Medical School, testimonybefore U.S. Senate Committee on Health, Education, Labor,and Pensions, Subcommittee on Public Health, hearing on“Children’s Health: Protecting Our Most Precious Resource,”September 16, 1999; accessed April 28, 2000, at http://www.senate.gov/~labor/hearings/septhear/091699wt/091699wt.htm.

19. Noreen M. Clark, “Management of Asthma by Parentsand Children,” in Self-Management of Asthma, ed. HarryKotses and Andrew Harver (New York: Marcel Dekker, Inc.,1998), 276-77.

20. Division of Health Promotion and Disease Prevention,prepublication copy/uncorrected proofs, “Clearing the Air:Asthma and Indoor Air Exposures,” Institute of Medicine,Washington, D.C., 2000, 1-4.

21. Rachel L. Miller, “Breathing Freely: The Need forAsthma Research on Gene-Environment Interactions,”American Journal of Public Health, 89 (June 1999): 820.

22. The IOM study meticulously reviewed available scientificevidence related to asthma causation. The authors carefullysifted through these data to rank causal factors as to whetherthere was (a) sufficient evidence of a causal relationship, (b)sufficient evidence of an association, (c) limited or sugges-tive evidence of an association, (d) inadequate or insufficientevidence to determine whether or not an association exists,or (e) limited or suggestive evidence of no association.

23. Recently, for example, the director of environmental healthfor the District of Columbia asked the area transportationauthority “to test expensive, cleaner-burning buses and moveaway from its all-diesel fleet,” because of a belief that dieselbuses are linked to a higher asthma rate among District resi-dents. See Lindsay Layton, “Drive against Diesel Buses Armedwith Asthma Data,” Washington Post, July 6, 2000, B4.

24. John Mansfield, Asthma Epidemic: Tackle the Causes,Find Relief Without Drugs (London: Thorson’s, 1997), 10.

25. As this background paper went to press, research findingsfrom Arizona suggesting that exposure of young children toolder children at home or to other children at day careprotects against the development of asthma were published inthe New England Journal of Medicine. See Thomas M. Ballet al., “Siblings, Day-care Attendance, and the Risk ofAsthma and Wheezing during Childhood,” New EnglandJournal of Medicine, 343 (August 24, 2000), 538-43.

26. Shell, “Does Civilization.”

27. National Heart, Lung, and Blood Institute, PracticalGuide for the Diagnosis and Management of Asthma, NIHPublication 97-4053 (Bethesda, Md.: National Institutes ofHealth, October 1997).

28. Camargo testimony.

29. Denise Grady, “Perseverance Is Key to a Good Life WithAsthma,” New York Times, October 19, 1999, D1, D5.

30. Arthur Allan, “Breath of Life: Childhood Asthma HasSkyrocketed in the Past Two Decades,” Washington PostMagazine, October 31, 1999, 8ff.

31. Allan, “Breath of Life.”

32. Marie C. McCormick et al., “Annual Report on Access toand Utilization of Health Care for Children and Youth in theUnited States, 1999,” Pediatrics, 105, no. 1 (January 2000):219-230.

33. John C. Carl, M.D., assistant professor of pediatrics, CaseWestern Reserve University School of Medicine, and mem-ber, Division of Pediatric Pulmonology, Rainbow Babies andChildren’s Hospital, Cleveland, Ohio, testimony before U.S.Senate Committee on Health, Education, Labor, and Pen-sions, Subcommittee on Public Health, hearing on “Chil-dren’s Health: Protecting Our Most Precious Resource,”September 16, 1999; accessed April 28, 2000, at http://www.senate.gov/~labor/hearings/septhear/091699wt/091699wt.htm..

34. Kevin B. Weiss, Peter J. Gergen, and Thomas A. Hodg-son, “An Economic Evaluation of Asthma in the UnitedStates,” New England Journal of Medicine 326 (1992): 862-866. The percentages sum to more than 100 because ofrounding.

35. Camargo testimony.

36. Health-Track, Blindfolding Public Health in the Fightagainst Asthma, Health-Track, Washington, D.C., May 22,2000.

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37. Dennis C. Stokes, M.D., testimony before U.S. SenateCommittee on Health, Education, Labor, and Pensions,Subcommittee on Public Health, hearing on “Children’sHealth: Protecting Our Most Precious Resource,” September16, 1999.