RESUMO
PURPOSE: The EQ-5D-5L is a preference-based instrument for measuring and valuing health-related quality of life (HRQoL). The EQ-5D-5L has been used extensively in economic evaluation, including in aged care. However, older adults' understanding of the EQ-5D-5L has not been comprehensively investigated to date. This research aimed to assess older adults' understanding of the EQ-5D-5L using a think-aloud protocol with two cognition groups: no cognitive impairment and mild/moderate cognitive impairment. METHODS: Participants' cognition was assessed using the Standardised Mini-Mental State Examination (SMMSE). Face-to face interviews were conducted with concurrent and retrospective think-aloud encouraged through verbal probing. Audio recordings were transcribed, and qualitative analysis, informed by the Tourangeau four-stage Response Model (comprehension, retrieval, decision process, response process) was conducted in NVivo. RESULTS: In total, 46 older adults (age 65 +) were recruited from 10 residential care facilities across South Australia (n = 25 no cognitive impairment, n = 21 mild/moderate cognitive impairment). Comprehension, retrieval, judgement and response mapping issues were common across all cognition levels and EQ-5D-5L dimensions. The two dimensions resulting in the most response issues were usual activities and personal care. CONCLUSION: Older adults may bring a different understanding to the EQ-5D-5L descriptive system than that expected given testing with general population samples. Dimension descriptors that are more relevant to this population may facilitate responses that better align with the underlying EQ-5D-5L concept model.