Readability of portuguese package leaflets : developing new and innovative metrics for their evaluation and improvement

Tese de doutoramento, Farmácia (Sócio Farmácia), Universidade de Lisboa, Faculdade de Farmácia, 2016Introduction: In the European Union, all medicines are distributed with a package leaflet (PL), which must be compliant with the pharmaceutical regulation. These documents must be readable, but linguistic metrics for the Portuguese PLs are unknown. Importantly, there are Portuguese software tools to linguistically evaluate texts, such as FreP or PreText. For instance, the words with ≥4 syllables are more difficult for readers. Objectives: 1) to perform a systematic review about PLs’ readability, 2) to evaluate regulatory, linguistic or graphic features in large samples of PLs and brand names of medicines (BNM), 3) to assess participants’ comprehension of PLs, and illustrations, tables, abbreviations and symbols (A&S) from PLs, and 4) to study participants’ memorization/pronunciation of BNM. Methods: Review study: the key-words ‘readability and package leaflet/insert’ were screened on b-on (2009-13); PRISMA criteria were applied. Descriptive studies: a) the presence of an initial list comprising all sections of the PLs or of mixed PLs (PLs describing more than one medicine) was checked and the number of pages was quantified in 2042 PLs; b) some obligatory (e.g. dosage) and facultative (e.g. overdose) regulatory aspects were confirmed in 651 PLs; c) all A&S were identified with PreText in 531 PLs, and qualitatively classified in groups (e.g. A&S of active substances); d) some linguistic features (e.g. words ≥4 syllables) were characterized with FreP in 531 PLs, plus 30 oral/journalistic texts (comparator texts); and e) the regulatory/linguistic issues of 474 BNM were evaluated. Experimental studies: a) studies enrolling university undergraduates of non-biomedical courses (UUNC) to evaluate participants’ comprehension of 373 A&S, and some illustrations/tables, b) studies with UUNC and clients of pharmacies to assess participants’ memorization/pronunciation of BNM written (or not) in accordance with the Portuguese orthographic system, c) a study to evaluate subjects’ comprehension of 12 PLs with 503 participants. Results: Review study: identification of readability issues (e.g. too technical information). Descriptive studies: the obligatory regulatory issues were compliant with the requirements, but potential readability/legibility problems were identified in PLs: lack of the initial list, a high proportion of mixed PLs and A&S, too long PLs, few illustrations/tables, and potential problematic BNM, such as names containing A&S. Linguistic study: PLs were linguistically considered more complex than common texts, for instance the words with ≥4 syllables were more prevalent in PLs than in journalistic or oral texts. Exploratory studies: participants’ comprehension of PLs was limited and the non-native names were worst memorized/read. Discussion and conclusion: Overall, regulatory, linguistic and comprehension issues were found, thus some PLs/BNM may need to be re-evaluated/optimized, such as simplifying/optimizing the text of PLs or adapting all BNM to Portuguese. Linguistic indicators may be used to check PLs’ clarity