Medication Adherence and Blood Pressure Control Among Hypertensive Outpatients Attending a Tertiary Cardiovascular Hospital in Tanzania: A Cross-Sectional Study

Abstract

Background: Notwithstanding the availability of effective treatments, asymptomatic nature and the interminable treatment length, adherence to medication remains a substantial challenge among patients with hypertension. Suboptimal adherence to BP-lowering agents is a growing global concern that is associated with the substantial worsening of disease, increased service utilization and health-care cost escalation. This study aimed to explore medication adherence and its associated factors among hypertension outpatients attending a tertiary-level cardiovascular hospital in Tanzania. Methods: The pill count adherence ratio (PCAR) was used to compute adherence rate. In descriptive analyses, adherence was dichotomized and consumption of less than 80% of the prescribed medications was used to denote poor adherence. Logistic regression analyses was used to determine factors associated with adherence. Results: A total of 849 outpatients taking antihypertensive drugs for ≥1 month prior to recruitment were randomly enrolled in this study. The mean age was 59.9 years and about two-thirds were females. Overall, a total of 653 (76.9%) participants had good adherence and 367 (43.2%) had their blood pressure controlled. Multivariate logistic regression analysis showed; lack of a health insurance (OR 0.5, 95% CI 0.3-0.7, p<0.01), last BP measurement >1 week (OR 0.6, 95% CI 0.4-0.8, p<0.01), last clinic attendance >1 month (OR 0.4, 95% CI 0.3-0.6, p<0.001), frequent unavailability of drugs (OR 0.6, 95% CI 0.3-0.9, p = 0.03), running out of medication before the next appointment (OR 0.6, 95% CI 0.4-0.9, p = 0.01) and stopping medications when asymptomatic (OR 0.6, 95% CI 0.4-0.8, p<0.001) to be independent associated factors for poor adherence. Conclusion: A substantial proportion of hypertensive outpatients in this tertiary-level setting had good medication adherence. Nonetheless, observed suboptimal blood pressure control regardless of a fairly satisfactory adherence rate suggests that lifestyle modification plays a central role in hypertension management.