Associated factors to non-adherence to blood pressure lowering drugs: Results from an urban Tunisian population 2017

Background: Patients’ poor or non-adherence to Blood Pressure (BP) lowering drugs is one of the main factors of suboptimal BP. We aimed to determine the prevalence of non-adherence to BP lowering drugs in hypertensive outpatients followed in our department, and assess associated factors. Methods: Descriptive observational study conducted between July 24th and November 24th, 2017 at the Rabta hospital in Tunis. According to the recommendations of the European Society of Cardiology (2013), outpatients over the age of 18, followed for High Blood Pressure (HBP) at high (or very high) risk of cardiovascular diseases, were included in this study. The sample was randomly selected among the list of outpatients followed for HBP. The adherence assessment test (TEO) developed by the French HBP control committee, was adopted to assess adherence level. Health-Related Quality Of Life (HRQL) was assessed by MINICHAL questionnaire. Data on socio-demographic and clinical characteristics were collected using a structured questionnaire. Socio-demographic and clinical characteristics and HRQL data were further tested as independent variables to non-adherence. Data entry and analysis were performed by SPSS software version 20.0. A two-sided p-value test was considered to be significant. Results: A total of 170 patients were included in this survey. The mean age of our study population was 63 ± 0.7 years, (52.9%) were men and (74.2%) had a low educational level. More than half of included patients were classified as hypertensive at very high risk of cardiovascular diseases (58.3%). The prevalence of non-adherence was (59.4%, 95% CI (52.3-67.1)). In multivariable analysis, factors associated with non-adherence were low educational level and having no family support to get treatment. HRQL scores were not significantly associated with non-adherence. Conclusion: Our study has highlighted a high prevalence of non-adherence to BP lowering drugs in a vulnerable population. Actions focused on three levels (patient, drug-treatment and healthcare system), should be undertaken to enhance adherence