Predictors of medication adherence for African American patients diagnosed with hypertension.

BACKGROUND The prevalence, morbidity and mortality of hypertension are strikingly higher for African Americans than for Whites. Poor adherence to the antihypertensive medication regimen is a major cause of inadequate blood pressure control. In this study, we assess the relationship of antihypertensive medication adherence to sociodemographic, clinical and cognitive characteristics of urban African American adults. METHOD Data were drawn from a larger randomized controlled trial assessing the effect of a behavioral intervention to improve medication adherence and blood pressure control among hypertensive African American patients followed in an urban primary care network. Medication adherence was assessed at baseline using the Medication Event Monitoring System (MEMS)--a method regarded as the gold standard for assessing medication adherence in clinical research. Information on potential correlates of medication adherence (sociodemographic, clinical and cognitive) was obtained at baseline by computer-assisted interview. We assessed the cross sectional association of these factors to medication adherence in baseline data. RESULTS Medication adherence was significantly associated with systolic blood pressure (r=.253, P<.04) and self-reported medication adherence (r=.285, P<.03). The relationship of education to medication adherence varied significantly by sex (P<.05 for interaction). Specifically, lower educational attainment was related to higher adherence among men, but lower adherence among women. CONCLUSION Identifying correlates of low antihypertensive medication adherence and their interactions, as in this study, will help health providers to better recognize patients at higher risk for worse hypertension-related outcomes. This knowledge can also inform interventions which target a higher-risk subset of hypertensive patients.