Abstract
Background: Adherence to long-term antihypertensive therapy is a basic requirement for blood pressure control and prevention of secondary complications. Several studies have reported highly variable levels of non-adherence among patients on long-term medication therapy. Therefore, the major aim of this study is to assess adherence and its determinants among patients on long-term antihypertensive therapy.
Methods: This was a six-month prospective study among a cohort of 125 eligible patients on therapy for at least four months. The enrolees included males (65.6%) and females (34.4%) with a mean age of 59.1 ± 11.8 years. Data on medications, comorbidities, duration of therapy and complications was obtained from medical records. Adherence was measured using the Morisky medication adherence scale questionnaire (MMAS-8) and scores were calculated accordingly. The association between sociodemographic variables and adherence was carried out using the Chi-square test and Fisher's exact test as appropriate and P values ≤ 0.05 were considered statistically significant.
Results: The results showed that the percentage of patients with adequate adherence was 47.3% [MMAS score ≥ 6] compared to those with low adherence [52.7%]. Demographic variables like age [p = 0.011], educational level [p = 0.038], marital status [p ≤ 0.001], comorbidity [p ≤ 0.001], place of residence [p = 0.008] and frequency of physician consultations [p ≤ 0.001] were associated with non-adherence. There is a need for pharmacists to provide solicited and unsolicited adherence support as part of their regular pharmaceutical care services to patients on long-term antihypertensive therapy.
Conclusion: The level of satisfactory adherence to antihypertensive medications was less than half of the subjects enrolled in the study. Adherence was found to be associated with the presence of comorbidity, marital status, age, educational status, rural/urban residence, and frequency of physician consultations. Poor adherence poses a significant increase in the risk of stroke and other complications.
Keywords: Adherence, antihypertensives, demographic variables, association, determinants