Adherence to Hypertension Treatment and its Determinants in Patients Referred to a Tertiary Cardiology Center in Urmia, Iran

Background and Objective: Adherence to antihypertension medications is an important factor in the control of hypertension. In this regard, the present study aimed to estimate the extent of medication adherence in hypertensive patients and its determinants in the special clinic of Seyed-al Shohada Cardiovascular Tertiary Hospital in Urmia, Iran. Materials and Methods: In this cross-sectional study, a total of 650 hypertensive patients were investigated during October to December 2016. In this study, two questionnaires were used to collect the data. The first questionnaire included the demographic and clinical characteristics, smoking status, family history of hypertension, and blood pressure measurements. The eight-item Morisky medication adherence scale was used to measure the extent of medication adherence of the participants. Moreover, the Chi-square test and logistic regression model were employed to identify the determinants of medication adherence. Results: Mean value of the participant age was reported as 59.5±10.4 years, and 63.5% of the subjects were female. Overall, 48%, 30.8%, and 21.2% of the subjects were reported with complete, moderate, and poor adherence, respectively. Among the investigated determinants, age (OR=1.02, 95% CI: 1.01-1.05), occupational status (OR=1.83, 95% CI: 1.19-2.83), absence of adverse effects of the drugs (OR=1.83, 95% CI: 1.02-2.71), use of two drugs (OR=1.75, 95% CI: 1.12-2.74), use of three drugs and more (OR=2.25, 95% CI: 1.30-3.88), and history of angioplasty (OR=1.80, 95% CI: 1.19-2.71) were associated with good adherence (i.e., complete and moderate) in this study. Only 39.4% of all participants had controlled level of hypertension. Conclusion: According to the obtained results, the patients with hypertension had good medication adherence. The determinants effective in medication adherence outlined in this study can help identify patients with low extent of adherence.