Medication Use and Adherence in Patients with Hypertension: A Prospective Study in Vietnam

Objective: to document patients’ antihypertensive agents, determine their medication adherence, and identify factors associated with the adherence. Material and Methods: A prospective study was performed on a group of hypertensive outpatients, with social health insurance, in Can Tho, Vietnam. The study included 330 patients over 18 years old, who agreed to participate and could listen, speak and answer questions in Vietnamese. The data collection method was based on prescriptions and patient interviews. Data were analyzed using descriptive statistics, and Generalized Estimating Equations with Poisson-log linear distribution. Results: Among the drug use characteristics, 76.1% were prescribed beta-blockers, 91.5% polytherapy, and 63.0% changed drugs at the third follow-up visit. The percentage of patients who adhered to medication ranged from 70.0% to 91.2%. Factors that improved drug adherence included: the academic level at high school or higher (39.0% increase), living in urban areas (15.0% increase), having a job related to social interaction (11.2%), and having a family history of hypertension (9.0% increase). Factors that reduced adherence included: advanced age (22.0% decrease), prolonged disease duration (16.0% decrease), prolonged treatment duration (11.0% decrease), and changes in at least one type of antihypertensive drug (8.0% decrease). Conclusion: The highlight of this study is the demonstration of an inverse relationship between the adherence rate and the number of follow-up visits: the higher the number of visits, the lower the adherence rate. The 3rd follow-up adherence rate was 70.0%, and the decreased adherence rate is related to older age, higher education levels, and a longer duration of treatment.