Perception of risk of hypertension related complications and adherence to antihypertensive drugs: a primary healthcare based cross-sectional study

BACKGROUND: Blood pressure control is suboptimal in more than half of treated hypertensive patients. The purpose of this study was to assess perceived risk of high blood pressure sequelae and adherence to medications in known cases of hypertension. METHODS: A cross-sectional study was designed using a sample of 600 hypertensive patients who were randomly selected from 32 primary healthcare centers in Shiraz, Iran. A structured interviewer-administered questionnaire was used to collect data. Participants were asked about their basic demographic information, smoking history, access to healthcare services, duration of antihypertensive therapy, number of drugs taken concurrently and their perceived risk of hypertension-related complications. The outcome of interest was adherence to antihypertensive medications measured by the Persian version of the Morisky Medication Adherence Scale (MMAS-8). Multivariate logistic regression analysis was used to identify independent factors associated with better adherence. RESULTS: Nearly half (48.8%) of participants had uncontrolled hypertension. Just over one fifth (22.3%) of all the patients reported high adherence to antihypertensive medications. Independent factors associated with better adherence to antihypertensive medications were higher educational level (OR: 1.71, CI 95%: 1.06–2.75), being a never smoker (OR: 1.62, CI 95%: 1.06–2.46), having easy access to healthcare services (OR: 1.91, CI 95%: 1.10–3.35), lower mean treatment duration (OR: 0.96, CI 95%: 0.92–0.99), and having higher perceived risk of hypertension-related complications (OR:2.34, CI 95%: 1.52–3.60). CONCLUSION: High perceived risk of hypertension-related complications is significantly associated with adherence to antihypertensive therapy. Our findings suggest that primary care physicians should regularly emphasize on negative consequences of uncontrolled/poorly controlled blood pressure while visiting hypertensive patients.