Assessing determinants of self-medication with antibiotics among Portuguese people in the Algarve Region

Background Misuse of antibiotics gives rise to numerous individual and societal problems, among which antimicrobial resistance is currently a major worldwide concern. Understanding cultural features in the public’s attitudes and behaviours regarding antibiotics and their use is a prerequisite to developing effective educational interventions. Objective To estimate the prevalence of self-medication with antibiotics and evaluate the predictive factors associated with such self-medication. Setting The general population, drawn from town halls, supermarkets, hotels, food malls, restaurants, sports groups and Senior Colleges. Methods A cross–sectional study was conducted by convenience sampling the adult population living in the Algarve, Portugal. The information about self-medication with antibiotics was assessed by using a validated self-administrated questionnaire. Factors associated with self-medication were identified through bivariate analysis and a logistic regression model. Results Of the 2,000 questionnaires distributed, 1,198 were returned, representing a response rate of 59.9 %. A total of 1,192 individuals were included in the study. The mean age was 46.6 ± 16.9 years and 48.7 % (95 % CI 46–52 %) were male. The majority of individuals said that they had returned the leftover antibiotics to the pharmacy for destruction. However, 268 respondents (22.5 %, 95 % CI 20–25 %) said they had disposed of their medication through the garbage or the sewage system. 218 respondents (18.9 %, 95 % CI 17–21 %) were assumed to have already taken antibiotics without a prescription and 267 (23 %, 95 % CI 21–25 %) reported having leftover antibiotics at home. The factors that influence self-medication with antibiotics were age; in particular, the risk is higher in the youngest group 18–34 years: OR 4.57 (95 % CI 2.23–9.39; p < 0.001), and in the 50–64 year group: OR 2.33 (95 % CI 1.08–5.03; p = 0.03); and the male gender: OR 2.88 (95 % CI 1.86–4.46; p < 0.001). The risk was lower in respondents who said that it was not easy to get antibiotics without a prescription: OR 0.07 (95 % CI 0.05–0.12; p < 0.001). Conclusion Non-prescription acquisition, age and gender could be determinants of self-medication with antibiotics among Portuguese people in the Algarve region.