Background: Patient non-adherence to antibiotic therapy may lead to therapeutic failure, re-infection, and bacterial resistance. Assessing the factors associated with this problem is important for promoting rational use of antibiotics.
Objective: This study aimed to measure prevalence and reasons for non-adherence to antibiotic treatment and to identify associated factors.
Method: Patients were recruited for the study in community pharmacies in Lisbon, Portugal, from February to April, 2009. Data from prescriptions for oral antibiotics were collected for adult subjects. Adherence to treatment was assessed with a modified Portuguese version of the Morisky scale. Factors associated with non-adherence were identified through bivariate analysis and logistic regression models.
Results: A total of 243 patients were included in the study. They had a mean age 46.5 ± 16.6 years and 74.5 % of the sample was female. The prevalence of non-adherence was 57.7 % and was related to delays and failures in taking the prescribed medicine. Increasing age (OR 0.97), difficulty in buying the antibiotic (OR 2.34), duration of treatment (OR 1.28), difficulty with ingestion (OR 3.08), and satisfaction with the information given by physician (OR 0.33) were identified as independent factors associated with non-adherence.
Conclusion: Non-adherence to antibiotics is common in the community setting. Factors related to the antibiotic, the patient, and the patient-physician relationship should be addressed to promote adherence. Pharmacists should provide information to patients about correct use of antibiotics and address barriers to adherence.