Presentation on theme: "Rising Infant Mortality in Delaware: An Examination of Racial Differences in Secular Trends Ashley Schempf Charlan Kroelinger, PhD Bernard Guyer, MD, MPH."— Presentation transcript:
Rising Infant Mortality in Delaware: An Examination of Racial Differences in Secular Trends Ashley Schempf Charlan Kroelinger, PhD Bernard Guyer, MD, MPH
Background The Delaware IMR has been rising since the mid 90s
Background Findings from a prior analysis (MMWR) IMR Increase: 2/3 from VLBW mortality 1/3 from VLBW infants Increase in VLBW mortality primarily occurred among older, married, privately insured women living in a suburban county 3/4 of VLBW mortality increase attributed to multiple births Centers for Disease Control and Prevention. Increasing infant mortality among very low birthweight infants--Delaware, 1994-2000. MMWR 2003;52:862-6.
Objective To examine potential racial differences in the IMR increase and its determinants
Analytic Framework State Infant Mortality Collaborative Framework Stage 1: Overview of maturity-specific components (birthweight or gestational age) Stage 2: Focused examination of determinants of stage 1 components Maternal attributes, environment, health care
Methods Data Linked birth/infant death cohort files for two periods: ’93-’97 and ’98-’02 Inclusion criteria: White or Black race with non- missing birthweight (97% of all births) Analytic Methods Stage 1: Kitagawa analysis of birthweight-specific components by race Stage 2: Examination of maternal characteristics related to the component increases by race
Stage 1: Kitagawa Method To decompose the difference between two rates into changes in birthweight distribution and changes in birthweight-specific mortality rates P 1i = Proportion of infants born in birthweight category i in 1993-1997 (per 100) P 2i = Proportion of infants born in birthweight category i in 1998-2002 (per 100) R 1i = Mortality rate among infants born in birthweight category i in 1993-1997 (per 1,000) R 2i = Mortality rate among infants born in birthweight category i in 1998-2002 (per 1,000) Total Mortality Change = from birthweight category i distribution component rate component Kitagawa E. Components of a difference between two rates. J Am Stat Assoc 1955;50:1168.
Stage 2 Methods Compositional changes in maternal attributes and birth characteristics Direct standardization Regression adjustment Within group changes to identify the groups that experienced the greatest increases Characteristics included maternal age, education, marital status, first trimester prenatal care, insurance, county, smoking status, parity, and plurality
Stage 1 Results For both races, the IMR increase was confined to VLBW infants Whites: 1/2 due to VLBW mortality, 1/2 due to VLBW infants Blacks: 2/3 due to VLBW mortality, 1/3 due to VLBW infants Decomposition of the IMR Increase by Race
Stage 2 Results Compositional changes were slight and favorable for the most part teen childbearing early prenatal care uninsured Increase in multiple births Whites: + 20% Blacks: + 33%
Adjustment for compositional changes Relative (%) Increase From Logistic Models Direct Standardization (Absolute Scale) The increase in multiple births explained ~20% of overall IMR increase No other changes in composition contributed to the increase
Characteristics related to VLBW infants Increase only significant for White infants Rise in multiple births accounted for 2/5 of % VLBW Increase greater for younger maternal age less education medicaid insurance smokers % VLBW
Characteristics related to VLBW mortality For both Whites and Blacks, the increase is associated with advantaged characteristics Multiple births accounted for majority of excess VLBW deaths White: 84% Black: 67% VLBW Mortality Rate Ratios
Conclusions Given the advantaged correlates of the IMR increase for both races, traditional strategies of targetting disadvantaged women and increasing access to prenatal care would not reverse trends Hypotheses for further exploration ART and multiple births Declines in maternal/infant health Shift from fetal to infant deaths
Multiple Births The increase in multiple births and their mortality rate accounted for 2/3 of White IMR increase and 1/2 of Black IMR increase ART is associated with worse outcomes among singleton and multiple births From 1998-2003, % ART conceived multiple births doubled from 11% to 22% Racial disparities in access related to insurance coverage Unclear why the role of ART would be different in Delaware than other states Linked files will be necessary to evaluate the ART contribution
Maternal/Infant Health Status The increased incidence and mortality of VLBW infants may suggest declines in maternal and/or infant health All of the IMR increase was confined to early neonatal deaths Research at Christiana Hospital has noted increasing illness severity among VLBW infants (Paul et al) PRAMS & FIMR are being implemented Paul DA, Leef KH, Locke RG et al. Increasing illness severity in very low birth weight infants over a 9-year period. BMC Pediatr 2006;6:2.
Shift from Fetal to Infant Deaths Fetal mortality rates have declined at Christiana Hospital May be due to changes in: Obstetric care Classification Registration
Eliminating the Racial Disparity Black infants represented 1/4 of all births but 1/2 of excess deaths between the two time periods Elimination of the 2.2 fold IMR disparity would return the overall IMR to baseline levels Medicaid compared to private insurance had lower % VLBW for Black women (2.9% v. 3.8%)
State Initiatives Governor Minner convened an Infant Mortality Task Force and has allocated $2 million of FY2007 funds for: Statewide Healthy Mother & Infant Consortium Center for Excellence in MCH Epidemiology PRAMS and FIMR Direct services to high-risk women for preconception, prenatal, and interconception care
Acknowledgements Funding support for this analysis was provided by an MCHB Maternal and Child Health Epidemiology Training Grant