A global survey of antibiotic leftovers in the outpatient setting.

We performed a global survey of outpatients who had taken self-administered antibiotics within the last 12 months in order to identify factors that lead to possession of leftover antibiotics in the community. The study included 4,514 subjects aged 18-99 years. Of 4,192 respondents not currently taking antibiotics, 53.7% admitted having leftover antibiotics, of whom 77.0% saved them, 4.6% gave them away and 18.4% threw them away. Living in a country where antibiotics are dispensed in fixed packs rather than exact numbers of pills as well as believing that leftover antibiotics can be saved and used again were the strongest predictors for possession of leftovers. There was also a marked detrimental effect of lack of information from the doctor and/or pharmacist. This investigation suggests that dispensing of antibiotics in exact numbers of doses should be recommended in addition to the development of relevant information campaigns addressing patients' false beliefs about leftovers and the provision of basic information about the importance of completing antibiotic treatment.