Worth the paper they are printed on? Findings from an independent evaluation of the understandability of patient information leaflets for antiseizure medications

OBJECTIVE: The Patient Information Leaflet (PIL) is an authoritative document that all people with epilepsy in the EU receive when prescribed antiseizure medication (ASM). We undertook the first independent, comprehensive assessment to determine how understandable they are. Regulators state that when patients are asked comprehension questions about them, ≥80% should answer correctly. Also, recommended is that PILs have a maximum reading requirement of US grade 8. METHODS: Study 1: We obtained 140 current ASM PILs written in English. "Readability" was assessed using four tests, with and without adjustment for influence of familiar, polysyllabic words. A total of 179 online materials on epilepsy were also assessed. Study 2: Two PILs from Study 1 were randomly selected (Pregabalin Focus; Inovelon) and shown to 35 people from the UK epilepsy population. Their comprehension was assessed. Study 3: To understand whether the student population provides an accessible alternative population for future examination of ASM PILs, Study 3 was completed, using the same methods as Study 2, except that participants were 262 UK university students. RESULTS: Study 1: No PIL had a reading level of grade 8. Median was grade 11. Adjusting for context, the PILs were still at grade 10.5. PILs for branded ASMs were most readable. PILs were no more readable than (unregulated) online materials. Study 2: Users struggled to comprehend the PILs' key messages. The eight questions asked about pregabalin were typically answered correctly by 54%. For Inovelon, it was 62%. Study 3: Most student participants comprehended the PILs' key messages. The questions about Inovelon were answered correctly by 90%; for pregabalin it was 86%. SIGNIFICANCE: This is the first independent and comprehensive examination of ASM PILs. It found that PILs being used fail to meet recommendations and regulatory requirements and risk not being understandable to a substantial proportion of users. In finding that people from the epilepsy population differ markedly in comprehension of PILs compared to students, this study highlights the importance of completing user testing with the target population.