Evaluation of antidiabetic medication adherence in the Lebanese population: development of the Lebanese Diabetes Medication Adherence Scale

Objective To evaluate factors affecting adherence to oral antidiabetic treatment in the Lebanese population and to develop the Diabetes Medication Adherence Scale (DMAS) based on these factors. Methods A cross-sectional study was conducted on a sample of Lebanese diabetic patients. Data were collected using a structured questionnaire. The level of adherence was measured using the Lebanese Medication Adherence Scale (LMAS-14). Bivariate analyses and multivariable analysis was done using SPSS. Psychometric evaluation of DMAS included an assessment of internal consistency, factor analysis, evaluation of sensitivity and specificity. Criterion-related validity was assessed by comparison with LMAS-14 measure of adherence. Key findings A total of 500 patients were recruited. 39.2% were adherent to treatment. Long working hours, increased number of oral antidiabetic medication per day, drug discontinuation when travelling, longer duration of diabetes and treatment burden were among factors that decreased adherence. While understanding the treatment regimen, following up physician recommendations and following up the recommended diet contributed to good medication adherence. The final 7-item scale (DMAS) had a good internal consistency (Cronbach's alpha = 0.612) and a good correlation and agreement with LMAS-14 (Spearman's rho = 0.699, Cohen's kappa = 0.566). Patients with high DMAS scores were significantly more likely to have controlled glycaemia (P < 0.05). Sensitivity and specificity reached 70.39% and 51.47%, respectively. Conclusion Adherence to oral antidiabetic treatment is suboptimal in Lebanon. The DMAS is a reliable instrument for assessing adherence and predicting poor glycaemic control in clinical practice, but requires further validation in other populations.