Differences in Coronary Heart Disease and Stroke Incidence Among Single‐Race and Multiracial Asian and Pacific Islander Subgroups in Hawaii and California: A Retrospective Cohort Study

BACKGROUND: Little is known about clinical and sociodemographic factors affecting coronary heart disease (CHD) and stroke incidence in single-race and multiracial American Asian, Native Hawaiian, and Pacific Islander subgroups. As the US population becomes more diverse, it is important to characterize differences in risks for CHD and stroke, and their contributing factors, in these populations. METHODS AND RESULTS: The study population included 303 958 patients from Kaiser Permanente Hawaii and Palo Alto Medical Foundation in California. Self-reported race and ethnicity were derived from electronic health records and 12 mutually exclusive single-race and multiracial groups were created for analyses. Cox proportional hazard models were used to compare CHD and stroke incidence. Unadjusted models were compared with models adjusted for age, income, education, body mass index, smoking, and comorbidities. We found up to a 4-fold variation in CHD and stroke rates among American Asian, Native Hawaiian, and Pacific Islander subgroups. Multiracial subgroups had higher rates than single-race groups. While most single-race American Asian, Native Hawaiian, and Pacific Islander groups had lower CHD and stroke risks, middle-aged Asian Indian men and Native Hawaiian women had higher stroke risks than non-Hispanic White controls. Income, education, body mass index, smoking, and comorbidities contributed significantly to risks in all groups, especially in Native Hawaiian, Pacific Islander, and multiracial groups. CONCLUSIONS: Risks for CHD and stroke vary by racial and ethnic subgroups, demonstrating the need to unmask risks by disaggregating racial and ethnic subgroups. Multiracial American Asian, Native Hawaiian, and Pacific Islander groups had higher risks that were only partially explained by modifiable risk factors. Future studies should further explore lifestyle, psychosocial, and sociocultural factors.