User testing on Foods with Function Claims labelling in Japan :An attempt to establish an integrated evaluation system for the usefulness of health information materials

The saturation of self-care products in the market is coupled with inadequate information on their safe usage. In Japan, although foods with function claims (FFC) are prevalent, their labelling falls short in quality and effectiveness as health information, impeding consumer comprehension and proper utilization. Hence, it is imperative to establish a system that assesses the efficacy of labelling information from both provider and user perspectives. From providers or healthcare professionals perspective, we already developed a Communication Index to assess FFC labelling, which we utilized to evaluate five FFC products. Those products achieved a proficiency level of approximately 70%, falling below the acceptance criteria. Particularly, challenges were identified in understanding some of the terms and locating important information on the labels. In this study, we conducted user-testing from the user perspective for five same FFC labels to evaluate them using semi-structured interviews with 50 participants of diverse ages and sexes. A passing criterion for comprehension was set as [≥]90% correct responses to all questions. Of the five FFC products, one passed the user-testing criterion with a 2-min response time; however, none passed the 1-min response time test. The proportions of correct answers were notably low for questions on diet and allergies (each 50-90%), concomitant medications (50-100%), storage (30-100%), and handling (30-100%). Participants comments revealed a lack of familiarity with FFC, highlighting that the terms and text in the labelling were confusing and overly technical. User-testing provides valuable insights for improving FFC labelling, thereby ensuring safe and appropriate use by aligning with consumers understanding and perceptions. We assessed FFC label information from both the provider and user perspectives, but neither yielded satisfactory results. Consequently, the implementation of an integrated system capable of evaluating FCC labels as health information material from both perspectives would be necessary.