infant mortality: an overview of determinants and prevention opportunities for regions iv and vi...
TRANSCRIPT
Infant Mortality: An Overview of
Determinants and Prevention
Opportunities for Regions IV and VI
Ashley H. Schempf, PhDOffice of Epidemiology, Policy and Evaluation
Maternal and Child Health BureauHealth Resources and Services Administration,
DHHS
Outline• Basic epidemiology• Background• Data from 2004-2006 Period Linked Live
Birth / Infant Death File• Timing and Causes of Death• Contribution of Preterm Birth• Contribution of Racial Disparities
• Promising avenues for intervention
Background• Infant mortality is a sentinel
population health indicator
• Health of babies depends on the health of the population—not only mothers but fathers, families, and society
• US infant mortality rate (6.7 per 1,000 births)
• 28th among industrialized countries
• Recent plateau after long decline
Period of Death
Neonatal (<28 days)
• Comprise 2/3 of all deaths
• Driven by PTB/LBW, maternal/newborn health, risk-appropriate care
• Moderately preventable given current knowledge
Postneonatal (28-364 days)
• Comprise 1/3 of all deaths
• Driven by SIDS, injury, infection
• Highly preventable with current knowledge
67%
33%
Neonatal
Postneonatal
Infant Mortality by Period of Death
• Difference between Region IV and Other Regions is equally apportioned to excess neonatal and postneonatal mortality
• Difference between Region VI and the other regions is mostly postneonatal
U.S. Region IV Region VI Other Regions
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
4.55.3
4.4 4.3
2.3
2.9
2.62.0
PostneonatalNeonatal
Death
s p
er
1,0
00
8.2
6.8
7.0 6.
3
Leading Causes of DeathUnderlying Cause* Death Rate
Per 100,000% of
Deaths
Prematurity and related conditions 206.3 30.5%
Congenital anomalies 136.3 20.1%
SIDS/SUID 81.0 12.0%
Obstetric conditions 47.4 7.0%
External causes 36.5 5.4%
Perinatal infections 33.7 5.0%
Other infections 21.0 3.1%
Birth Asphyxia 11.1 1.6%
All other causes 103.9 15.3%
U.S. 2004-2006
*ICD-10 codes grouped by modified Dolfus classification scheme
What are the causes of excess infant death in
Regions IV and VI?Underlying Cause
Region IVRate
Ratio*
% of excess deaths
Region VIRate
Ratio*
% of excess deaths
Prematurity and related conditions 1.34 35% 0.97 -8%
Congenital anomalies 1.10 7% 1.16 31%
SIDS/SUID 1.53 20% 1.52 52%
External causes 1.49 8% 1.19 9%
Perinatal infections 1.39 6% 1.14 6%
Other infections 1.52 5% 1.30 8%
*Compared to all other regions; only causes contributing ≥5% shown
Preterm Birth
Gestational Age % of Births
% of Deaths IMR
<28 weeks 0.8% 46.2% 406.9
28-31 weeks 1.3% 8.5% 44.7
32,33 weeks 1.6% 3.9% 16.3
34-36 weeks 9.0% 9.8% 7.2
All preterm, <37 weeks
12.7% 68.3% 36.1
All term, 37+ weeks 87.3% 31.7% 2.4
U.S. 2004-2006
• About 2/3 of all deaths occur among preterm births• Almost half occur among those born <28 weeks
Late Preterm Birth• Accounts for ~10% of infant deaths• May be highly preventable• Largest component of PTB increase in
90’s• Preliminary data indicate 5%↓ 2006-
2009• IMR also has begun to decline again
• Promising Interventions• Physician/patient/hospital education to
reduce non-indicated late preterm / early term births• Ohio Perinatal Quality Collaborative
• March of Dimes Tool Kit
Racial DisparitiesU.S. Region IV Region VI Other
Regions
White IMR 5.7 6.3 6.4 5.4
Black IMR 13.5 14.0 13.1 13.3
Black-White Risk Ratio
2.4 2.2 2.0 2.5
Black-White Risk Difference
7.9 7.6 6.7 8.0
% Black Births 14% 25% 14% 11%
• Racial disparities are persistent and striking in every region• Somewhat lower in Regions IV and VI because of higher rates
among Whites (higher poverty is a key factor)• Excess infant mortality would remain even if disparity were
eliminated
What would happen if disparities were
eliminated?Current Levels
U.S. Region IV
Region VI
Other Regions
0.01.02.03.04.05.06.07.08.09.0
6.8
8.2
76.3
Black IMR = White IMR
0.0
2.0
4.0
6.0
8.0
10.0
5.7 6.3 6.15.4
Death
s p
er
1,0
00
=1.9
=0.8
Disparities explain 56% of the gap between Region IV and Other Regions
Determinants of Black-White Disparity
• 2/3 neonatal, 1/3 postneonatal• Neonatal contribution is driven by excess PTB,
particularly <28 weeks• Postneonatal contribution driven by SIDS,
injury, and infection; prematurity also increases vulnerability
• Excess PTB accounts for 80% of disparity, ~60% from 3 fold disparity at <28 weeks*
• Proximate causes: infection, vascular disorders• Distal determinants include lifecourse SES,
environment, stress/discrimination, intergenerational factors
* Schempf A, Branum A, Lukacs S, Schoendorf K. The Contribution of Preterm Birth to the Black-White Infant Mortality Gap: US, 1990 and 2000. American Journal of Public Health, 2007;97(7):1255-1260.
Guiding Frameworks/Resources
• Lifecourse/Multiple Determinants
• Perinatal Periods of Risk (PPOR)
• AMCHP State Infant Mortality Collaborative toolkit
Potential Avenues• Maternal health• Chronic conditions, obesity• Smoking
• Unintended pregnancy, birth spacing• Paternal involvement• SIDS/SUID preventionHealth Care Factors• Regionalization (Title V Indicator)• Health insurance (mothers and children)• Preventing non-indicated late preterm/early term
births• Preconception care, new models of care
CDC, Behavioral Risk Factor Surveillance System
Current Population Survey, Annual Social and Economic Supplement
Current Population Survey, Annual Social and Economic Supplement
MCHB, Title V Information System
AcknowledgementsMichael D. Kogan, PhD
Director, Office of Epidemiology, Policy and Evaluation
Cassie Lauver, ACSWDirector, Division of State and Community
Health
Peter C. van Dyck, MD, MS, MPHDirector, Maternal and Child Health Bureau