Non-Adherence to Prescribed Antihypertensives in Primary, Secondary and Tertiary Healthcare Settings in Islamabad, Pakistan: A Cross-Sectional Study

OBJECTIVE: This study aimed to assess the prevalence and predictors of non-adherence to antihypertensive medication among patients with hypertension attending various healthcare settings in Islamabad, Pakistan. METHODS: A questionnaire-based cross-sectional study was conducted in selected healthcare facilities between September 2017 and December 2018. The study was conducted in primary, secondary and tertiary healthcare settings in Islamabad, Pakistan. Medication adherence was assessed using the eight-item Morisky Medication Adherence Scale (MMAS-8). Sociodemographic and clinical data of recruited patients were collected through a structured questionnaire. Binary logistic regression analysis was performed to determine covariates significantly associated with medication adherence and blood pressure control. RESULTS: A total of 776 hypertensive patients were invited and 741 (95%) completed the questionnaire. The mean ± SD age of participants was 53.6±12.6 years; 284 patients (38.3%) had high adherence, 178 (24%) had moderate adherence and 279 (37.7%) were non-adherent to the prescribed antihypertensive therapy. Binary regression analysis revealed that old age (OR 1.783 [95% CI: 1.172–2.712]; P=0.013), being educated (OR 2.018 [95% CI: 1.240–3.284]; P=0.036), entitlement to free medical care (OR 1.369 [95% CI: 1.009–1.859]; P=0.044), treatment duration (OR 2.868 [95% CI: 1.913–4.299]; P=0.001), number of medications (OR 1.973 [95% CI: 1.560–2.495]; P=0.001), presence of any comorbidity (OR 2.658 [95% CI: 1.836–3.848]; P=0.001) and blood pressure control (OR 3.103 [95% CI: 2.268–4.247]; P=0.001) were significantly associated with good adherence. Similarly, age (OR 1.998 [95% CI: 1.313–3.040]; P=0.004), entitlement to free medical care (OR 1.498 [95% CI: 1.116–2.010]; P=0.007), treatment duration (OR 1.886 [95% CI: 1.143–3.113]; P=0.013), presence of any comorbidity (OR 1.552 [95% CI: 1.123–2.147]; P=0.008) and adherence level (OR 3.103 [95% CI: 2.268–4.247]; P=0.001) had significant association with controlled blood pressure. The following were the main reasons for non-adherence to prescribed antihypertensive medication: “don’t feel need for regular use“ (24.7%), “Carelessness“ (13.4%) and “adverse effects“ (11.2%). CONCLUSION: The prevalence of non-adherence to antihypertensive medications was high in the study population and poor medication adherence could potentially explain poor blood pressure control. Evidence-based targeted interventions on both medication adherence and blood pressure control should be introduced and implemented for better treatment outcomes.