Discrimination, Mediating Psychosocial or Economic Factors, and Antihypertensive Treatment: A 4-Way Decomposition...

Untested psychosocial or economic factors mediate associations between perceived discrimination and suboptimal antihypertensive therapy. This study included 2 waves of data from Health and Retirement Study participants with self-reported hypertension (n = 8,557, 75% non-Hispanic White, 15% non-Hispanic Black, and 10% Hispanic/Latino) over 4 years (baselines of 2008 and 2010, United States). Our primary exposures were frequency of experiencing discrimination, in everyday life or across 7 lifetime circumstances. Candidate mediators were self-reported depressive symptoms, subjective social standing, and household wealth. We evaluated with causal mediation methods the interactive and mediating associations between each discrimination measure and reported antihypertensive use at the subsequent wave. In unmediated analyses, everyday (odds ratio (OR) = 0.86, 95% confidence interval (CI): 0.78, 0.95) and lifetime (OR = 0.91, 95% CI: 0.85, 0.98) discrimination were associated with a lower likelihood of antihypertensive use. Discrimination was associated with lower wealth, greater depressive symptoms, and decreased subjective social standing. Estimates for associations due to neither interaction nor mediation resembled unmediated associations for most discrimination-mediator combinations. Lifetime discrimination was indirectly associated with reduced antihypertensive use via depressive symptomatology (OR = 0.99, 95% CI: 0.98, 1.00). In conclusion, the impact of lifetime discrimination on the underuse of antihypertensive therapy appears partially mediated by depressive symptoms.