Does the association between depressive symptoms and cardiovascular mortality risk vary by race? Evidence from the Health and Retirement Study.

OBJECTIVE: To test whether the association between depressive symptoms and cardiovascular disease (CVD) mortality is stronger among Blacks than Whites.

DESIGN, SETTING AND PARTICIPANTS: 2,638 Black and 15,132 White participants from a prospective, observational study of community-dwelling Health and Retirement Study participants (a nationally representative sample of U.S. adults aged > or = 50). Average follow-up was 9.2 years.

OUTCOME MEASURE: Cause of death (per ICD codes) and month of death were identified from National Death Index linkages.

METHODS: The associations between elevated depressive symptoms and mortality from stroke, ischemic heart disease (IHD), or total CVD were assessed using Cox proportional hazards models to estimate adjusted hazard ratios (HRs). We used interaction terms for race by depressive symptoms to assess effect modification (multiplicative scale).

RESULTS: For both Whites and Blacks, depressive symptoms were associated with a significantly elevated hazard of total CVD mortality (Whites: HR=1.46; 95% CI: 1.33, 1.61; Blacks: HR=1.42, 95% CI: 1.10, 1.83). Adjusting for health and socioeconomic covariates, Whites with elevated depressive symptoms had a 13% excess hazard of CVD mortality (HR=1.13, 95% CI: 1.03, 1.25) compared to Whites without elevated depressive symptoms. The HR in Blacks was similar, although the confidence interval included the null (HR=1.12, 95% CI: .86, 1.46). The hazard associated with elevated depressive symptoms did not differ significantly by race (P>.15 for all comparisons). Patterns were similar in analyses restricted to respondents age > or =65.

CONCLUSION: Clinicians should consider the depressive state of either Black or White patients as a potential CVD mortality risk factor.