Cognitive interviewing for assessing the content validity of older-person specific outcome measures for quality assessment and economic evaluation: a scoping review

Abstract

Purpose: Older people (aged ≥ 65 years) are significant users of health and social care systems. However, many outcome measures for quality assessment and economic evaluation lack content validation for this population. Cognitive interviews are a key approach for generating content validity evidence. This systematic scoping review aimed to synthesise evidence on cognitive interviewing practices with older adults, including those with cognitive impairment and dementia, to determine the content validity of outcome measures used with these populations in health and social care settings.

Methods: A search was conducted across five databases, and results were uploaded to Covidence review management software. Two researchers performed screening and data extraction using a custom template. The initial search identified 8814 articles. After removing duplicates and conducting title and abstract screening, 105 articles remained. Full-text screening excluded 86 references, resulting in 19 included articles.

Results: Studies utilised various cognitive interviewing approaches, predominantly concurrent think-aloud combined with verbal probing. Inductive analysis based on Tourangeau's four-stage response model was commonly used for analysing verbal protocol data. Only one in four included studies indicated any allowances to alleviate cognitive burden for older participants. There was limited involvement of older people with cognitive impairment and dementia, but studies including these populations reported several modifications enhancing meaningful inclusion.

Keywords: Cognitive impairment; Cognitive interviewing; Content validity; Older adults; Quality of life; Think-aloud.