Exploring variables associated with medication non-adherence in patients with COPD

Background: Research has indicated that medication adherence is low and represents a barrier to achieve the desired health outcome in patients with Chronic Obstructive Pulmonary Disease (COPD). Objective: The aim of the study was to investigate the factors that are significantly associated with self-reported medication non-adherence in patients with COPD. Setting: Patients attending the outpatient respiratory clinic at the Royal Medical Services (RMS) Hospital in Amman. In addition to socio-demographics, validated measures including COPD knowledge questionnaire, the 4-item self-reported Morisky medication adherence scale, St George respiratory questionnaire and Health Anxiety and Depression scale were used in the present study. The stepwise logistic regression analysis was performed in order to identify variables that independently and significantly predicted medication non-adherence. Main outcome measure: Predictors of medication non-adherence. Results: A total of 133 patients participated in the study. Results indicated that majority of the patients (61.7%) were non-adherent. According to the model, patients were four times more likely to be non-adherent if they reported having depression (OR 0.251, CI 0.24–0.76) and approximately eight times to have medication non-adherence if they suffered from comorbid illness (OR 0.119, CI 0.11–0.80). Study participants were found to have a double risk of medication nonadherence if they received an increase in the frequency of administration of their COPD medication (OR 0.524, CI 0.08–0.69) and being concerned about side effects (OR 0.515, CI 0.36–0.92). Conclusion: Depression, dosage regimen complexity, the presence of co-morbidities and therapy side effects have significantly influenced adherence to COPD therapy in the present study. Clinical pharmacists should provide emotional support, simplify dosage regimen, use adherence aids, elicit patients' concerns about their illness comorbidities, select treatments with less side effect and help the patients coping with side effects in order to enhance adherence and health outcomes in patients with COPD.