The Perinatal Periods of Risk Approach

CityMatCH Training August 25, 2007

Denver, Colorado

Phase 1 Analytic Methods

Workshop ObjectivesDuring this session, participants will have the opportunity to:

• Recognize and understand the PPOR approach and its six stages

• Learn how to assess “community readiness”• Learn how to assess “analytic readiness”

• Understand what it takes to conduct the first phase of analysis

Six Stages:Perinatal Periods of Risk Approach

Stage 1: Assure Analytic and Community Readiness 

Stage 2: Conduct Analytic Phases of PPOR Stage 3: Develop Strategic Actions for Targeted

Prevention Stage 4: Strengthen Existing and/or Launch New

Prevention InitiativesStage 5: Monitor and Evaluate ApproachStage 6: Sustain Stakeholder Investment and

Political Will

DEFINITIONS

Traditional Infant Mortality Rate “IMR” is deaths before first birthday, per thousand live births

=deaths x 1,000 ÷ births

This can be done for any subpopulation, for example, the White IMR would be white deaths before first birthday, per thousand white live births

Definitions

Ideally, we use a BIRTH COHORT, count births in one year, and watch those babies until they reach their first birthday (must wait until the end of the following year ) to count deaths.

Often, we use a DEATH COHORT count births in one year, count deaths IN THE SAME YEAR. This is an easy way to approximate the true mortality rate.

Infant Mortality Rate,Infant Mortality Rate,Urban County, 1990-2001Urban County, 1990-2001

0.0

5.0

10.0

15.0

20.0

25.0

30.0

Black

White

Source: DHHS

What do PPOR analytic methods bring “to the table”

The Importance of Fetal DeathsOne difference between PPOR and traditional analysis is that PPOR includes fetal deaths, an important part of the picture.

Fetal and Infant Mortality Rates, 5 Urban Counties

8.5

9.2

7.1

9.9

7.9

8.9

5.7

8.3

6.1

7.2

0 5 10 15 20

Urban E

Urban D

Urban C

Urban B

Urban A

FetalInfant

PPOR Uses a Reference Group

• A subpopulation with optimal outcomes or an external population

• Comparison of target population with reference group helps target deaths that could be prevented.

PPOR Examines Deaths in TWO dimensions simultaneously:

• Age at death

• Weight at birth

Conce

ption Birt

h1

Year

Fetal Infancy20 wks 28 wks

4 wks

Spontaneous Abortion

Early Fetal

Late Fetal Neonatal

Postneonatal

Infant

Feto-Infant

Age at Death

The First Dimension Of PPOR Analysis:

Second Dimension: Birthweight

• Very Low Birthweight (PPOR limit)= less than 1500 grams (3.3 pounds)

• Low Birthweight= less than 2500 grams (5.5 pounds)

• Normal Birthweighte.g., a 7.5-pound baby weighs 3,400 grams

Birth

weig

ht

PPOR ANALYTIC METHODS Steps of Analytic Preparation

Acquire access to three required vital records computer files

Prepare vital records files and required data elements

Assess data quality

Assess study sample size

PPOR Analytic PreparationPPOR Analytic Preparation

• Fetal death certificate files (24+ wks, 500+ grams)

• Infant death certificate files (500+ grams)

• Live birth files (500 + grams)

• Linked birth—infant death certificate files are needed to find birth information for the infants who died

• Spontaneous and induced abortions are NOT included (they are not given certificates)

Analytic Preparation—Number of DeathsAnalytic Preparation—Number of Deaths

• At least sixty deaths overall and at least ten deaths in each period of risk, for each population being studied

• May combine UP TO 5 years to reach adequate number of deaths (no more, due to changes in medical practice)

• Phase 2 analyses require even more deaths.

Analytic Preparation – Data QualityAnalytic Preparation – Data Quality

• Serious bias is introduced if more than 5-10% of births, deaths, and fetal deaths are missing key data items such as birthweight, age at death, and maternal characteristics.

• Imputation (educated guessing) can help when key data are missing: e.g. if gestational age >=31 weeks we impute birthweight >=1500 grams

Relationship Between Gestational Age and Median Birthweight

0

500

1000

1500

2000

2500

3000

3500

Gestational Age (Weeks)

Infant DeathsFetal Deaths

Imputation I: Fetal Deaths

GA>=32 BW>=1500Y

N

GA>=24 Y500<=BW<1500

BW Unknown

N

<500

BW>=500 GA >=24Y

<24

GA Unknown

Imputation II: Infant Deaths

GA>=31 BW>=1500Y

NGA>=22 Y

500<=BW<1500

BW Unknown

N

<500

N / A

GA Unknown

What is PPOR Analysis?

Analytic Phases of PPOR Analytic Phases of PPOR

Phase 1Phase 1: Identifies populations and periods of risk with the largest excess mortality.

Phase 2Phase 2: Explains why the excess deaths occurred.

PPOR Maps Fetal & Infant Deaths

Age at Death

Birth

weig

ht

500-1499 g

1500+ g

Fetal

(24+

wks

)

Neonat

al

Postneo

natal

1 2 3

54 6

PPOR Maps Fetal & Infant Deaths

500-1499 g

1500+ g

Fetal Death Neonatal

Post- neonatal

Maternal Health/ Prematurity

Maternal Care

Newborn Care

Infant Health

Birth

weig

ht

Age at Death

PPOR is about ACTION(each period of risk is associated with a set of possible areas for action)

Maternal Health/

Prematurity

Maternal Care

Newborn Care

Infant Health

Preconception Health Health Behaviors Perinatal Care

Prenatal Care High Risk Referral Obstetric Care

Perinatal Management Neonatal Care Pediatric Surgery

Sleep Position Breast Feeding Injury Prevention

PPOR Map of Feto-Infant Deaths

83 Fetal Deaths are sorted into two periods of risk

Urban County, All Races2000-2002

35 Fetal DeathsMaternal Health/ Prematurity

48 Maternal

Care (fetal deaths)

PPOR Map of Feto-Infant Deaths

Of the 23,199 Infants born alive, 153 died. These are sorted into three periods of risk

Urban County, All Races2000-2002

62 Infant DeathsMaternal Health/ Prematurity

(live births)

44 Newborn

Care (live births)

47Infant Health

(live births)

PPOR Map of Feto-Infant Deaths

236 Feto-Infant Deaths

Urban County, All Races2000-2002

97Maternal Health/ Prematurity

(35 fetal deaths, 62 live births)

48 Maternal

Care (fetal deaths)

44 Newborn

Care (live births)

47Infant Health

(live births)

PPOR ANALYTIC METHODS Steps of Phase 1

Define study population

Restrict study population by birthweight and gestational age

Calculate numbers and rates for the feto-infant mortality map

Compare different time periods, subpopulations and geographic areas

Steps of Phase 1 Defining the Study Population Include mothers who are RESIDENTS

of the target area at the time of the baby’s birth.

Define the baby’s race/ethnicity according to the mother’s.

Include multiple gestations. Include congenital anomalies.

PPOR Map of Feto-Infant Deaths

23,199 live births

153 died as infants

83 fetal deaths

Denominator is 23,199 + 83 = 23,282

Urban County, All Races2000-2002

97Maternal Health/ Prematurity

(35 fetal deaths, 62 live births)

48 Maternal

Care (fetal deaths)

44 Newborn

Care (live births)

47Infant Health

(live births)

Calculating Feto-Infant Mortality Rate

4.2 + 2.1 + 1.9 + 2.0

= 10.1

Period rates add up to overall rate (except for round-off error)

Urban County, All Races2000-2002

2.1 Maternal

Care

1.9 Newborn

Care

2.0Infant Health

Maternal Health/ PrematurityRate=deaths x 1,000 ÷ births =97 deaths x 1,000 ÷ 23,282

= 4.2

White non-Hispanic

3.1

2.0 1.9 1.6

White Fetal-Infant

Rate = 8.6 (N=16,045)

Black non-Hispanic

2.4 4.02.4

8.8

Black Fetal-Infant

Rate =17.6 (N=3,291)

PPOR Map of Feto- Infant Mortality Urban County, By Race, 2000-2002(N=number of live births and fetal deaths)

STOP HERE ANALYTIC EXERCISE CALCULATE RATES

PPOR ANALYTIC METHODS More Phase 1 Steps:

“THE GAPS”

Select reference population Calculate excess mortality rates and

numbers of deaths Identify excess mortality gaps

PPOR Redefines Disparities, Estimates “Opportunity” Gap

ASK: Which women/infants have the ""best"best" outcomes?

ASSUMEASSUME: allall infants can have similar “best” outcomes

CHOOSECHOOSE: a comparisoncomparison groupgroup(s) (‘reference group’)(s) (‘reference group’) who already has achieved “best” outcomes

COMPARECOMPARE: fetal-infant mortality rates in your targettarget group with those of the comparison group(s)

CALCULATECALCULATE: excessexcess deaths (= target – comparison groups). This is your community’s “Opportunity Gap“Opportunity Gap..””

Reference Groups

Choose an easily defined optimal group •At least 15% of the population•At least 60 deaths•Acceptable to the community

U.S. National Reference Group:•20 or more years of age•13 or more years of education•Non-Hispanic white women

USA Reference Group 1998-2000• Defined by maternal characteristics

– 20 or more years of age– 13 or more years of education– Non-Hispanic white women– residents of the US at the time of baby’s

birth

2.2

1.5 1.1 1.0

Total Fetal-Infant Mortality Rate = 5.9

Calculating ExcessCalculating Excess RatesRates Overall population Urban County, 2000-2002

(external reference group)

Urban County

Maternal Health/

Prematurity

Maternal Care

Newborn Care

Infant

Health

Fetal-Infant Mortality

all 4.2 2.1 1.9 2.0 10.1

USA Reference

Group

Maternal Health/

Prematurity

Maternal Care

Newborn Care

Infant

Health

Fetal-Infant Mortality

2.2 1.5 1.1 1.0 5.9

Excess Mortality

Rate

Maternal Health/

Prematurity

Maternal Care

Newborn Care

Infant

Health

Fetal-Infant Mortality

By Subtraction 2.0 0.6 0.8 1.0 4.3

____________________________________________________________

Feto-Infant Mortality Rates Racial/Ethnic subgroups of Urban County, 2000-2002

(external reference group)Racial Groups

Maternal Health/

Prematurity

Maternal Care

Newborn Care

Infant Health

Overall Feto-Infant

Mortality

White, non-Hispanic

3.1 2.0 1.9 1.6 8.6

Black, non-Hispanic

8.8 2.4 2.4 4.0 17.6

Hispanic and other races

4.6 2.0 1.3 2.3 10.2

External Reference Group

2.2 1.5 1.1 1.0 5.9

ExcessExcess Feto-Infant Mortality RatesBased on USA 1998-2000 reference group

Racial/Ethnic Groups

Maternal Health/

Prematurity

Maternal Care

Newborn Care

Infant Health

Feto-Infant Mortality

White, non-Hispanic 0.9 0.5 0.8 0.6 2.8

Black, non-Hispanic 6.6 0.9 1.3 3.0 11.8

Other Races 2.4 0.5 0.2 1.3 4.4

All 2.0 0.6 0.8 1.0 4.3

CALCULATING EXCESS CALCULATING EXCESS NUMBERNUMBER OF DEATHS OF DEATHSFROM Fetal-Infant Mortality Rates

using External Comparison Group Urban County, 2000-2002

Racial/ Ethnic GroupExcess

Mortality Rate

Live Births and Fetal

deathsMultiply

Number of Excess Deaths

White Non-Hispanic 2.8 16,0452.8*16,045

1,000=45

Black Non-Hispanic 11.8 3,29111.8*3,291

1,000=39

Other Race 4.43,947 4.4*3,947

1,000=17

All4.3 23,282

4.3*23,2821,000

=101

Urban County by RaceUrban County by Race 2000-2002 estimated Excess Number of Deaths

based on external comparison group

Racial/Ethnic Groups

Maternal Health/

Prematurity

Maternal Care

Newborn Care

Infant Health

Feto-Infant Mortality

White, non-Hispanic 14 8 13 10 45

Black, non-Hispanic 22 3 4 10 39

Other Races 9 2 1 5 17

All 46 13 18 25 101

ANALYTIC EXERCISECALCULATE EXCESS MORTALITY AND

ESTIMATE EXCESS NUMBER OF DEATHS

Feto-Infant Mortality Rates in the Internal Comparison Group

(Best Outcomes in Urban County)Urban County, 2000-2002

2.4

2.2 1.8 1.0

Total Fetal-Infant Mortality Rate = 7.4

• Defined by maternal characteristics– 20 or more years of age– 13 or more years of education– Non-Hispanic White women– Residents of Urban County at time of

baby’s birth

ExcessExcess (Internal) (Internal) Fetal-Infant Mortality Rates

Overall population Urban County, 2000-2002

Urban County

Maternal Health/

Prematurity

Maternal Care

Newborn Care

Infant

Health

Fetal-Infant Mortality

4.2 2.1 1.9 2.0 10.1

Internal Reference

Group

Maternal Health/

Prematurity

Maternal Care

Newborn Care

Infant

Health

Fetal-Infant Mortality

2.4 2.2 1.8 1.0 7.4

Excess Mortality

Rate

Maternal Health/

Prematurity

Maternal Care

Newborn Care

Infant

Health

Fetal-Infant Mortality

By Subtraction 1.7 -0.1 0.1 1.0 2.7

____________________________________________________________

Fetal-Infant Mortality Rates Urban County, by Race,

Internal Comparison Group 2000-2002Racial Groups

Maternal Health/

Prematurity

Maternal Care

Newborn Care

Infant Health

Overall Feto-Infant

Mortality

White, non-Hispanic

3.1 2.0 1.9 1.6 8.6

Black, non-Hispanic

8.8 2.4 2.4 4.0 17.6

Hispanic and other races

4.6 2.0 1.3 2.3 10.2

Internal Reference Group 2.4 2.2 1.8 1.0 7.4

Urban County by RaceUrban County by Race 2000-2002 Excess Fetal-Infant Mortality Rates

based on internal comparison group

Racial/Ethnic Groups

Maternal Health/

Prematurity

Maternal Care

Newborn Care

Infant Health

Feto-Infant Mortality

White, non-Hispanic 0.7 -0.2 0.1 0.6 1.2

Black, non-Hispanic 6.4 0.2 0.6 3.0 10.2

Other Races 2.2 -0.2 -0.5 1.3 2.8

All 1.7 -0.1 0.1 1.0 2.7

Urban County by Race 2000-2002 Estimated Excess Number of Deaths

based on internal comparison group

Racial/Ethnic Groups

Maternal Health/

Prematurity

Maternal Care

Newborn Care

Infant Health

Feto-Infant Mortality

White, non-Hispanic 10 -3 1 10 19

Black, non-Hispanic 21 1 2 10 33

Other Races 8 -1 -2 5 11

All 40 -3 2 24 63

• Builds data and epi capacity

• Promotes effective data use

• Strengthens essential partnerships

• Fosters integration with other key efforts

• Encourages evidence-based interventions

• Helps leverage resources

• Enables systems change for perinatal health

PPOR is about impactimpact and resultsresults:

• Please remember to turn in your evaluations !

Perinatal Periods of Risk: For More Information:

www.citymatch.org

By looking at the numbers in a new way, we can finally understand fetal/infant mortality and its common causes. Only through understanding can we take steps to ensure every child gets a chance at life.

The Perinatal Periods of Risk Approach

CityMatCH Training August 25, 2007

Denver, Coloradowww.citymatch.org

Phase 1 Analytic Methods