Background: Non-adherence to prescribed medications represents an obstacle toward achieving treatment goals. This problem is more pronounced in patients with chronic illness.
Objective: To identify the extent of adherence in Lebanese outpatients with chronic diseases, and to suggest possible predictors of non-adherence in this population. The secondary objective was to assess if medication adherence affects patients' quality of life.
Methods: A questionnaire was administered face-to-face to a sample of Lebanese adults visiting the external clinics at two Tertiary Care Hospitals in Beirut. The level of adherence was assessed using the 8-item Morisky Medication Adherence Scale which was first validated. The health-related quality of life (HRQoL) of patients was measured using the EQ-5D. Linear regression and logistic regression analyses examined possible predictors of adherence.
Results: Out of the 148 patients included in this study, 42.6% were classified as adherent. In the univariate analyses, statistically significant predictors of high adherence included good physician-patient relationship (p=0.029) and counseling (p=0.037), a high level of HRQoL (p<0.001), and a high level of perceived health (p<0.001). Predictors of low adherence included a declining memory (p<0.001), anxiety/depression (p=0.002), little drug knowledge (p<0.001), and postponing physician appointments (p<0.001). The multivariate analyses revealed similar results. In the linear regression, the most powerful predictor of non-adherence was the disbelief that the drug is ameliorating the disease (beta=0.279), however, in logistic regression, patient who were willing to skip or double doses in case of amelioration/deterioration were found to be 7.35 times more likely to be non-adherent than those who were not (aOR=0.136, 95% CI: 0.037-0.503).
Conclusion: The findings of this study reassure the view that patients should be regarded as active decision makers. Patient education should be regarded as a cornerstone for treatment success. Additional studies as well are needed to test the practicability and effectiveness of interventions suggested to enhance adherence.
Keywords: Causality; Lebanon; Medication Adherence; Multivariate Analysis; Prevalence.