DOI: 10.4018/IJEHMC.2017040104 Copyright © 2017, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited. International Journal of E-Health and Medical Communications Volume 8 • Issue 2 • April-June 2017 Automatic Quantification of Abbreviations in Medicine Package Leaflets and Their Comprehension Assessment Carla Pires, Faculty of Pharmacy, University of Lisbon, Lisbon, Portugal Fernando Martins, School of Arts and Humanities, University of Lisbon, Lisbon, Portugal Afonso Cavaco, Faculty of Pharmacy, University of Lisbon, Lisbon, Portugal Marina Vigário, School of Arts and Humanities, University of Lisbon, Lisbon, Portugal ABSTRACT Medication errors occur as a consequence of misunderstandings with abbreviations and symbols (A&S). According to pharmaceutical regulations, A&S should be avoided in medicine package leaflets (PLs). Using a sample of 531 Portuguese PLs, this study aims at: quantifying A&S in PLs, comparing how A&S were distributed, identifying non-recommended units of measure, checking whether the full meaning of abbreviations was presented, and determining educated peoples’ interpretation of A&S. A computational tool was used to identify A&S. Participants’ comprehension was evaluated with a questionnaire. Overall, 828 different A&S were identified. PLs of prescribing medicines contained a significantly higher proportion of A&S than PLs of over-the-counter medicines (chi-square = 13.4; p = 0.004). A&S with their meaning not fully described and units of measure with a non-recommended format were identified. Only 9.9% of the questionnaire answers were correct. Portuguese PLs may need to be revised. The software used is appropriate to checking A&S in PLs. KEywoRdS Abbreviations, Medicinal Products, Package Leaflets, Patient Safety, Readability INTRodUCTIoN Currently, there is an increased interest in shaping medical information, as a way of ensuring readers’ adequate use and comprehension of written health materials (Vromans et al., 2013). The use of abbreviations and symbols (A&S) may be considered a more efficient way of transmitting certain types of written information, 47