Factors Influencing Antihypertensive Medication Adherence Among Historically Underrepresented Adults

BACKGROUND: Addressing disparities in blood pressure control must include supporting antihypertensive medication adherence (MA). Developing effective MA interventions requires identifying the most important factors influencing MA. OBJECTIVE: In this review, the authors aimed to meta-analyze the results of research testing associations between factors potentially influencing antihypertensive MA and assessed antihypertensive MA in historically underrepresented populations. Additional exploratory analyses focused on system-level factors, which have been understudied and may particularly impact disparities in MA. METHODS: A health sciences librarian assisted with searching across 10 databases. Inclusion criteria included (1) published in English, (2) sample of adults with hypertension, (3) ≥50% of participants having self-identified as a race/ethnicity underrepresented in the country where the study was conducted, and (4) reporting sufficient data to calculate effect size(s). RESULTS: Fifty-eight studies were eligible for inclusion. Nine factors met criteria for planned analyses. Older age ( r = 0.08, P < .01; k = 26 studies) and higher income ( r = 0.11, P = .01; k = 15) were significantly correlated with better MA. Having depressive symptoms was significantly correlated with worse MA ( r = -0.18, P < .01; k = 11). Effect sizes for sex, education level, marital status, number of medications, comorbidities, and perceived social support were not significant. System-level factors examined included insurance coverage, access to healthcare, perceived barriers, having a primary care provider, perceptions of their healthcare provider, and experiences of discrimination in healthcare. CONCLUSIONS: Understanding the impact of factors associated with antihypertensive MA in historically underrepresented adults can support development of targeted, culturally relevant MA interventions. Future research should examine the impact of system-level factors on antihypertensive MA among historically underrepresented populations.