A Cross-Sectional Study on Hypertension Medication Adherence in a High-Burden Region in Namibia: Exploring Hypertension Interventions and Validation of the Namibia Hill-Bone Compliance Scale

Abstract

In Namibia, the prevalence of hypertension among women and men aged 35–64 years is high, ranging from 44% to 57%. In this study, we aimed to determine adherence and predictors to antihypertensive therapy in Khomas region, Namibia. A cross-sectional study was performed to consecutively sample 400 patients from urban and peri-urban settings in Namibia. Results were validated using the Hill-Bone Compliance to High Blood Pressure Therapy Scale. Crude associations between predictors of adherence and compliance were tested using the Pearson chi-square test. A multivariable logistic regression analysis was then performed on adherence variables found to be significant to adjust for confounders, and the results are presented as adjusted odds ratios (aOR) with 95% confidence intervals. A total of 400 patients participated in this study. The participants’ mean age and standard deviation were Mean ± SD = 48.9 ± 12.5. In this study, 351 (87.7%) patients were estimated to have good adherence. Education, employment, and the presence of other chronic diseases were associated with adherence. Following multivariate adjustment, the following factors were significantly associated and are therefore predictors of adherence (95%CI, p < 0.005): receiving enough medication at last check-up until next one (OR = 5.44, CI 1.76–16.85), lack of encouragement from family and friends (OR = 0.11 (0.03–0.42)), and attendance of follow-ups on schedule (OR = 8.49, CI = 3.82–18.85). The success of hypertension therapy is dependent on the healthcare systems and healthcare professionals in supplying enough medication, support of friends/family, and maintaining scheduled follow-ups. A combination of interventions using low-cost mobile technology led by healthcare professionals could be endorsed. To fully practice universal access to medication, public and private hospitals in Namibia should collaborate.