Abbreviations and Symbols in a Large Sample of Medicinal Package Leaflets: Automatic Detection and Comprehension Assessment

Medicines package leaflets (PL) need to be clear and comprehensible, according to legal recommendations. Abbreviations and symbols (A&S) are not recommended since their use may lead to misunderstandings and medication errors. Objectives 1) identify, typify and quantify all A&S in a large sample of Portuguese PL, 2) detect discrepancies between these A&S and regulations, and 3) assess how educated individuals interpret A&S found in Portuguese PL. Methods descriptive and exploratory study. Descriptive study - 531 PL were visually inspected in order to identify all A&S and a computer tool was programmed to count these A&S. All A&S were typified according to classificatory groups (e.g. abbreviations of diseases names) and evaluated according to the regulations. Exploratory study - the interpretation of 373 A&S by 26 undergraduates was assessed with a questionnaire. Results 828 different A&S were identified (6407 occurrences). The average number of A&S per PL was 12.1 (SD=13.1). Thirteen classificatory groups were built. Non-compliant A&S were found. Only a very low percentage of responses was correct (9.9%). Conclusion A&S were prevalent in PL, contrary to the international recommendations. A significant number of technical A&S was unfamiliar to a group of educated people. Automatic tools and procedures regarding these readability features should be developed in order to validate PL's compliance with regulations.