Face and content validity and acceptability of the Swedish ICECAP-O capability measure: Cognitive interviews with 70-year-old persons

This study is part of a project that aims to culturally adapt the Investigating Choice Experiments for the Preferences of Older People-CAPability Index (ICECAP-O) for use in research and health and social care in Sweden. The objective was to evaluate face and content validity and acceptability. Eighteen 70-year-old community-dwelling persons participated in cognitive interviews. A standardized classification scheme was used to quantify any identified response problems, and a thematic analysis was applied to capture participants' perceptions of included attributes and experiences of completing the measure. The results show that three participants (18%) had problems completing ICECAP-O, and that judged problems occurred for five (6%) of participants responses in the standardized classification scheme. Most participants perceived the attributes as understandable even though the meaning of Control brought some uncertainty. ICECAP-O seems to measure what it is supposed to measure, quality of life (QoL) with a capability approach, and acceptability is satisfactory. ICECAP-O has potential for becoming a valuable addition to the supply of QoL measures in research and health and social care in Sweden. However, we recommend further research on more diverse groups of older persons.