Beliefs about medicines and medication adherence: a prospective study in persons with chronic lung disease

Abstract

Background: Adherence to medication is crucial for achieving treatment control in chronic lung diseases. This prospective study refers to the “necessity-concerns framework†and examines the associations between patients’ beliefs about medicines at baseline and self-reported medication adherence after three and twelve months. Methods: 402 patients (49% asthma, 51% COPD; 49% female; mean age 56.7 years (SD=15.9)) were included in the study and completed the “Beliefs about Medicines-Questionnaire†(BMQ) at baseline. The “Medication Adherence Report-Scale†(MARS) was administered at 3-months (N=255) and at 12-months follow-up (N=171). Logistic regression models with the BMQ-subscales (“necessityâ€, “concernsâ€, “harmâ€, “utilityâ€, “overuseâ€) as explanatory variables and the dichotomized MARS score as dependent variable were computed for the asthma and the COPD sample, respectively. Sociodemographic, disease and treatment related variables were considered as potential confounders. Findings: Overall, one third of patients were completely adherent (16% in the asthma sample, 45% in the COPD sample). Among patients with COPD, “necessity†was significantly associated with medication adherence at three months (OR= 2.36, 95%-CI: 1.35-5.12) and “concerns†were significantly associated with medication adherence at three (OR= 0.55 95%-CI: 0.32-0.95) and at 12 months (OR= 0.36, 95%-CI: 0.17-0.79). However, in the asthma sample, no significant associations between beliefs about medicines and medication adherence were observed. Discussion: Beliefs about the necessity of medicines and concerns were relevant for medication adherence behaviour of patients with COPD, but not of patients with asthma. Findings emphasize the need of a disease-specific approach when studying influential and potentially modifiable factors for medication adherence in chronic conditions.