A qualitative investigation of older adults' conceptualization of quality of life and a think-aloud content validation of the EQ-5D-5L, SF-12v2, Warwick Edinburgh Mental Wellbeing Scale, and Office of National Statistics-4.

OBJECTIVES: Old age is characterized by declining health, comorbidities, and increasing health and social care service use. Traditionally, patient-reported outcome measures (PROMs) including the EQ-5D-5L and SF-12v2 have focused on health. Nevertheless, aged care often aims to improve broader elements of quality of life (QoL), captured by well-being measures, such as the Warwick Edinburgh Mental Wellbeing Scale (WEMWBS) and Office of National Statistics-4 (ONS-4). This study investigates older adults' conceptualization of QoL and the content validity of the EQ-5D-5L, SF-12v2, WEMWBS, and ONS-4 in measuring their QoL. METHODS: Qualitative cognitive think-aloud interviews were undertaken with older adults aged 75+, exploring their views on what was important to QoL and, for each measure, the relevance, acceptability, and interpretation of items; suitability of response options; and the comprehensiveness of the measure. Conceptualization of QoL was analyzed thematically and content validity using framework analysis. RESULTS: Twenty interviews were undertaken. Older adults' conceptualization of QoL centered on health, ability to perform usual activities, social contact, and emotional functioning. Possible response shift was observed, as older adults assessed their health relative to lower health expectations at their age or to people in worse states. Participants questioned the relevance of negatively phrased mental items and often preferred the functioning-focused EQ-5D-5L to more subjective ONS-4 and WEMWBS items. Domains suggested to improve comprehensiveness included social contact, coping, security, dignity, and control. CONCLUSIONS: These findings are useful to researchers developing new PROMs for older adults or for the developers of included PROMs considering permanently adapting or bolting-on domains to improve content validity in older adults.