Progress towards narrowing health disparities: first steps in sorting out infant mortality trend improvements among American Indians and Alaska Natives (AI/ANs) in the Pacific Northwest, 1984-1997.

BACKGROUND: Most AI/AN infant mortality rates (IMRs) remain higher than white rates. The Northwest Portland Area Indian Health Board (NPAIHB), serving 43 tribes, CDC and the Washington, Oregon, and Idaho health departments investigated AI/AN infant survival.
METHODS: NPAIHB completed linking computerized birth certificate and birth-death files. We used death and birth cohorts, StatXact and SAS to compare 3-state resident, single and multi-year IMRs, basing infant race on mother's race, regardless of Hispanic origin. We used CDC's National Infant Mortality Surveillance ICD-9 categories for cause-specific rates.
RESULTS: From 1984 to 1997, about 2100-2800 AI/AN births occurred annually. From 1984 to 1990, AI/AN IMRs were 1.8-2.4 fold higher than white rates. Then aggregate-year IMRs significantly declined from 16.3 in 1984-1987 to 6.7 in 1994-1997 (P < 0.0001), approaching the 5.6 1994-1997 white rate. In 1998 the AI/AN IMR rate increased to 10.3. AI/AN SIDS and respiratory distress syndrome rates decreased significantly, respectively, from 8.1 in between 1984-1987 to 2.3 in 1994-1996 and from 1.8 in 1984-1987 to 0.3 in 1991-1993, then leveled off. Significant rate declines occurred among most demographic, risk behavior, birthweight, gestational-age, reproductive risk, birth spacing, and labor/delivery sub-groups. Among others, AI/AN residents in Idaho as well as those who received no prenatal care and who had 0-5 month birth spacing experienced no improvements.
CONCLUSIONS: These uncommon rate declines imply multi-factorial improvements among Northwest AI/ANs. Community-level surveillance and interventions before conception through post-partum may further improve health. Collaborative efforts need to be maintained to continue to monitor changes in AI/AN infant health and maternal characteristics.