User testing as a method for identifying how consumers say they would act on information related to over-the-counter medicines

Background: User testing evaluates written medicine information (WMI) usability by examining participants’ ability to find and understand information. It can also be an effective method to determine how consumers say they will act on information on an over-the-counter (OTC) label. Objective: To examine consumers’ reported behaviors regarding dosage and storage as a measure of a medicine label’s usability and consumers’ functional health literacy. Material and methods: User testing of 5 diclofenac OTC labels (by 50 subjects; 10 per label) measured consumers’ ability to find and understand key points of information using a 13-item questionnaire. Consumers were required to elaborate on their behavior in regard to 2 additional questions: 1) when they would take diclofenac if they had constant back pain from 8am (dosage-related) and; 2) where they would store it in their home (storage-related). Responses were transcribed verbatim, and coded by 2 pharmacists. Results: Appropriate dosing for constant back pain was reported by 29 consumers. However, dosing intervals shorter than the specified 8 hours were often reported (n=19), due to adjusting intervals to accommodate up to the maximum of 8 tablets in 24 hours, desire for pain relief, and/or pragmatic dosing (e.g. around bedtime). Only 29 consumers stated completely appropriate storage location examples (e.g. medicine cabinet). Conclusions: Consumers may act inappropriately on OTC label information about dosage and/or storage, which could potentially adversely impact medicine use. User testing can contribute to the development of high quality WMI and help identify where label wordings are inappropriate for the health literacy levels of consumers.