Correlates of antihypertensive medication non-adherence among patients with hypertension

Abstract

Hypertension remains a significant global public health challenge affecting billions of adults and remains a risk factor for adverse cardiovascular outcomes such as heart attack, stroke, heart failure and premature mortality. Although the effect of the disease can be effectively attenuated by antihypertensive medication, suboptimal adherence to these medications continues to pose a significant challenge to effective management, as many patients fail to take their medication as prescribed. Understanding the multi-faceted determinants of non-adherence and is essential for developing targeted interventions, particularly in resource-limited settings, ultimately improving blood pressure control, reducing complications, and enhancing patient quality of life. A multicenter cross-sectional study was conducted among 602 persons living with hypertension across one tertiary hospital and five primary care clinics in Livingstone, Zambia. This study represents baseline data from an ongoing prospective cohort study, with the current analysis restricted to enrollment data. Therefore, all exposures and outcomes were measured at a single time point, consistent with a cross-sectional design. Medication non-adherence was defined as a Proportion of Days Covered (PDC) < 80%. Data on sociodemographic, clinical, economic and treatment-related factors were collected using structured questionnaires and medical record reviews. Logistic regression analysis was performed to identify factors independently associated with non-adherence to antihypertensive medication. The prevalence of non-adherence to antihypertensive medication was 65.8% (95% confidence interval (CI) 62.0% − 69.6%). In multivariate analysis, factors significantly associated with non-adherence were receiving care at specific primary care clinics (adjusted odds ratio (AOR) 10.06, 95%CI 3.49–28.94), Non-tertiary education (AOR 0.53, 95%CI 0.31–0.89), and being on dual or triple therapy (AOR 0.40, 95%CI 0.21–0.77). Non-adherence to antihypertensive medication is highly prevalent. The findings argue compellingly for a multi-pronged intervention strategy. At the health system level, standardizing and improving the quality of hypertension care across all clinical sites is imperative. At the clinical level, providers should prioritize investigating disease severity, patients willingness to control high blood pressure and address forgetfulness. Future longitudinal research is needed to confirm the association pathways suggested here.