Ethnic Differences in Risk of Coronary Heart Disease in a Large Contemporary Population

Racial/ethnic differences in diabetes and cardiovascular disease are well documented, but disease estimates are often confounded by differences in access to quality health care. The objective of this study was to evaluate the ethnic differences in risk of future coronary heart disease in patient populations stratified by status of diabetes mellitus and prior coronary heart disease among those with uniform access to care in an integrated healthcare delivery system in Northern California.

A cohort was constructed consisting of 1,344,899 members with self-reported race/ethnicity, aged 30-90 years, and followed from 2002 through 2012. Cox proportional hazard regression models were specified to estimate race/ethnicity-specific hazard ratios for coronary heart disease (with whites as the reference category) separately in four clinical risk categories: (1) no diabetes with no prior coronary heart disease; (2) no diabetes with prior coronary heart disease; (3) diabetes with no prior coronary heart disease; and (4) diabetes with prior coronary heart disease. Analyses were performed in 2015.

The median follow-up was 10 years (10,980,800 person-years). Compared with whites, blacks, Latinos, and Asians generally had lower risk of coronary heart disease across all clinical risk categories, with the exception of blacks with prior coronary heart disease and no diabetes having higher risk than whites. Findings were not substantively altered after multivariate adjustments.

Identification of health outcomes in a system with uniform access to care reveals residual racial/ethnic differences and point to opportunities to improve health in specific subgroups and to improve health equity.