Relationship between the Stages of Change and Medication Adherence in Patients with Type 2 Diabetes Mellitus in a Primary Health Care Setting in Qatar

Abstract

Background: Non-adherence to medications is a major concern among patients with type 2 diabetes mellitus (T2DM). Failure to achieve positive health-related outcomes could be associated with non-adherence. Medication non-adherence is considered a socio-behavioral problem, thus using a behavioral model such as the transtheoretical model (TTM) could improve it. Objective: The primary objectives of this study were: (1) to determine the TTM’s Stages of Change (SOC) and medication adherence scores of patients with T2DM in a primary health care setting in Qatar; (2) to determine the relationship between these two variables; and (3) to determine whether SOC could predict medication adherence whilst controlling for confounding factors. The secondary objectives were to assess the relationship: (1) between SOC and glycated hemoglobin (HbA1c); and (2) between medication adherence and HbA1c in the same population. Method: The study was conducted in the non-communicable disease clinic. Non-Qatari patients were recruited from Mesaimeer Health Care Center, whereas Qatari patients were recruited from Westbay Health Care Center. Medication adherence was measured using the eight-item Morisky Medication Adherence Scale (MMAS-8), and SOC was determined using a two-item SOC questionnaire. HbA1c values were obtained from the electronic medical records at the clinic. Spearman rank correlation was conducted at α level of 0.05 to determine the relationship between variables of interest, and hierarchical regression was performed to determine if SOC could predict medication adherence, while controlling for confounding factors. Results: A total of 387 patients were included in the analysis. The majority of the participants were non-Qatari (84.8% non-Qatari vs. 15.2% Qatari). The highest percentage of participants was in the maintenance stage (76.7%). The rate of low, medium, and high adherence to antidiabetic medications was 26.4%, 23.3%, and 50.3%, respectively. There was a significant positive correlation between SOC and adherence score (r= 0.728, p < 0.001), and SOC was able to significantly explain 58 % - 59 % of the variance when predicting medication adherence % (p < 0.001) while controlling for confounding factors. Conclusion: There was a strong association between SOC and medication adherence, suggesting that the two-item SOC questionnaire could potentially be used as a simple tool to identify patients at risk of low adherence.