[Self-reported hypertension and non-adherence to continuous-use medication in Brazil: a population-based study]

The aim of this study was to estimate the prevalence of non-adherence to several continuous-use drugs by patients 30 to 79 years of age with self-reported hypertension, and associated factors, drawing on data from the Brazilian National Sample Household Survey (PNAD-2008). Prevalence ratios (PR) and respective 95% confidence intervals (95%CI) were obtained by Poisson regression. The proportion of individuals that failed to adhere to continuous-use medication was 17%. Characteristics directly associated with non-adherence were: male gender, residence in the North, Northeast, or Central-West of Brazil, and smoking. Non-adherence decreased with age, per capita family income, number of chronic diseases, and medical consultation in the previous 12 months, and was inversely associated with 11 or more years of schooling (PR = 0.92; 95%CI: 0.86-0.98), not working and not being unemployed, and physical activity. Adherence to antihypertensive medication is necessary and requires investment in primary care, improved access to health services, and measures to offset regional, social, and gender inequalities.