Life Expectancy of American Indian and Alaska Native Persons and Underreporting of Mortality in Vital Statistics.

IMPORTANCE

Mortality of American Indian and Alaska Native (AI/AN) persons is known to be high but may be underreported in routine vital statistics.

OBJECTIVE

To estimate age-specific mortality rates and life expectancy for non-Hispanic AI/AN individuals and other racial and ethnic groups, using self-identified race and ethnicity data in a national cohort, circumventing errors due to racial misclassification on death certificates.

DESIGN, SETTING, AND PARTICIPANTS: This longitudinal cohort study used data from the Mortality Disparities in American Communities (MDAC) study, a nationally representative cohort created through the US Census Bureau's linkage of the 2008 American Community Survey (ACS) with death records from the National Vital Statistics System through 2019. The cohort included 4 135 000 ACS respondents, including 30 500 who self-identified as AI/AN (alone) and 58 000 who self-identified as AI/AN alone or in combination with another race (AI/AN-AiC).

EXPOSURE

Self-identified race and ethnicity.

MAIN OUTCOMES AND MEASURES

Age-specific mortality rates and life expectancy, estimated using continuous time, nonparametric period survival curves by self-identified race and ethnicity; comparisons to estimates from the US Centers for Disease Control and Prevention (CDC) WONDER database based on race and ethnicity reported on death certificates; and classification ratios for self-reported vs death certificate-recorded AI/AN race among decedents in the MDAC. Analyses were stratified by time period, sociodemographic factors, and cause of death.

RESULTS

Life expectancy of self-identified AI/AN individuals was 72.7 years (73.9 for AI/AN-AiC individuals), 6.5 years less than the US-wide average of 79.2 years. The AI/AN vs US average life expectancy gap widened from 4.1 years in 2008 to 2010 to 8.0 years in 2017 to 2019. Among self-identified AI/AN and AI/AN-AiC decedents, only 59.0% and 39.8% had AI/AN race reported on their death certificates, yielding classification ratios of 1.26 and 1.81, respectively. AI/AN race was most frequently underreported for heart disease and cancer deaths and less frequently for deaths from violence, drugs, and alcohol. In CDC WONDER data (based on race and ethnicity from death certificates), age-standardized mortality was 5% higher for AI/AN individuals than the US average (1067 vs 1016 deaths per 100 000). In MDAC data, mortality for self-identified AI/AN individuals was 42% higher (1420 vs 999 deaths per 100 000). The AI/AN life expectancy gap was 2.9 times larger in the MDAC than in unadjusted official statistics.

CONCLUSIONS AND RELEVANCE

This longitudinal cohort study found that large life expectancy differences between AI/AN individuals and other US residents have been underestimated due to racial misclassification on death certificates, resulting in the statistical erasure of Indigenous people in routine vital statistics.