The Perinatal Periods of Risk Approach CityMatCH Training August 25, 2007 Denver, Colorado Phase 1 Analytic Methods
Workshop Objectives During 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 Initiatives Stage 5: Monitor and Evaluate Approach Stage 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, Urban County, Source: DHHS
What do PPOR analytic methods bring “to the table”
The Importance of Fetal Deaths One difference between PPOR and traditional analysis is that PPOR includes fetal deaths, an important part of the picture.
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
Conception Birth 1 Year Fetal Infancy 20 wks28 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 Birthweight e.g., a 7.5-pound baby weighs 3,400 grams Birthweight
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 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 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 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
Imputation I: Fetal Deaths GA>=32 BW>=1500 Y N GA>=24 Y 500<=BW<1500 BW Unknown N <500 BW>=500 GA >=24 Y <24 GA Unknown
Imputation II: Infant Deaths GA>=31 BW>=1500 Y N GA>=22 Y 500<=BW<1500 BW Unknown N <500 N / A GA Unknown
What is PPOR Analysis?
Analytic Phases of PPOR Phase 1 Phase 1: Identifies populations and periods of risk with the largest excess mortality. Phase 2 Phase 2: Explains why the excess deaths occurred.
PPOR Maps Fetal & Infant Deaths Age at Death Birthweight g g Fetal (24+ wks) NeonatalPostneonatal
PPOR Maps Fetal & Infant Deaths g g Fetal Death Neonatal Post- neonatal Maternal Health/ Prematurity Maternal Care Newborn Care Infant Health Birthweight 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 Races Fetal Deaths Maternal 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 Races Infant Deaths Maternal Health/ Prematurity (live births) 44 Newborn Care (live births) 47 Infant Health (live births)
PPOR Map of Feto-Infant Deaths 236 Feto- Infant Deaths Urban County, All Races Maternal Health/ Prematurity (35 fetal deaths, 62 live births) 48 Maternal Care (fetal deaths) 44 Newborn Care (live births) 47 Infant 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, = 23,282 Urban County, All Races Maternal Health/ Prematurity (35 fetal deaths, 62 live births) 48 Maternal Care (fetal deaths) 44 Newborn Care (live births) 47 Infant Health (live births)
Calculating Feto-Infant Mortality Rate = 10.1 Period rates add up to overall rate (except for round-off error) Urban County, All Races Maternal Care 1.9 Newborn Care 2.0 Infant Health Maternal Health/ Prematurity Rate=deaths x 1,000 ÷ births =97 deaths x 1,000 ÷ 23,282 = 4.2
White non-Hispanic White Fetal-Infant Rate = 8.6 ( N=16,045) Black non-Hispanic Black Fetal-Infant Rate = 17.6 (N=3,291) PPOR Map of Feto- Infant Mortality Urban County, By Race, (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 "best" ASK: Which women/infants have the "best" outcomes? ASSUMEall ASSUME: all infants can have similar “best” outcomes CHOOSEcomparison group(s) (‘reference group’) CHOOSE: a comparison group(s) (‘reference group’) who already has achieved “best” outcomes COMPAREtarget COMPARE: fetal-infant mortality rates in your target group with those of the comparison group(s) CALCULATEexcess “Opportunity Gap.” CALCULATE: excess deaths (= target – comparison groups). This is your community’s “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 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 Total Fetal- Infant Mortality Rate = 5.9
Calculating Excess Rates Calculating Excess Rates Overall population Urban County, (external reference group) Urban County Maternal Health/ Prematurity Maternal Care Newborn Care Infant Health Fetal-Infant Mortality all USA Reference Group Maternal Health/ Prematurity Maternal Care Newborn Care Infant Health Fetal-Infant Mortality Excess Mortality Rate Maternal Health/ Prematurity Maternal Care Newborn Care Infant Health Fetal-Infant Mortality By Subtraction ____________________________________________________________
Feto-Infant Mortality Rates Racial/Ethnic subgroups of Urban County, (external reference group) Racial Groups Maternal Health/ Prematurity Maternal Care Newborn Care Infant Health Overall Feto- Infant Mortality White, non- Hispanic Black, non- Hispanic Hispanic and other races External Reference Group
Excess Excess Feto-Infant Mortality Rates Based on USA reference group Racial /Ethnic Groups Maternal Health/ Prematurity Maternal Care Newborn Care Infant Health Feto-Infant Mortality White, non- Hispanic Black, non- Hispanic Other Races All
CALCULATING EXCESS NUMBER OF DEATHS CALCULATING EXCESS NUMBER OF DEATHS FROM Fetal-Infant Mortality Rates using External Comparison Group Urban County, Racial/ Ethnic Group Excess Mortality Rate Live Births and Fetal deaths Multiply Number of Excess Deaths White Non-Hispanic2.816, *16,045 1,000 =45 Black Non-Hispanic11.83, *3,291 1,000 =39 Other Race4.4 3,9474.4*3,947 1,000 =17 All 4.323, *23,282 1,000 =101
Urban County by Race Urban County by Race 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 Black, non- Hispanic Other Races All
ANALYTIC EXERCISE CALCULATE EXCESS MORTALITY AND ESTIMATE EXCESS NUMBER OF DEATHS
Feto-Infant Mortality Rates in the Internal Comparison Group (Best Outcomes in Urban County) Urban County, 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
Excess (Internal) Excess (Internal) Fetal-Infant Mortality Rates Overall population Urban County, Urban County Maternal Health/ Prematurity Maternal Care Newborn Care Infant Health Fetal-Infant Mortality Internal Reference Group Maternal Health/ Prematurity Maternal Care Newborn Care Infant Health Fetal-Infant Mortality Excess Mortality Rate Maternal Health/ Prematurity Maternal Care Newborn Care Infant Health Fetal-Infant Mortality By Subtraction ____________________________________________________________
Fetal-Infant Mortality Rates Urban County, by Race, Internal Comparison Group Racial Groups Maternal Health/ Prematurity Maternal Care Newborn Care Infant Health Overall Feto- Infant Mortality White, non- Hispanic Black, non- Hispanic Hispanic and other races Internal Reference Group
Urban County by Race Urban County by Race 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 Black, non- Hispanic Other Races All
Urban County by Race 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 Black, non- Hispanic Other Races All
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 impactresults PPOR is about impact and results:
Please remember to turn in your evaluations !
P erinatal P eriods o f R isk: For More Information:
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, Colorado Phase 1 Analytic Methods