Systematic review of development and content validity of patient-reported outcome measures in Inflammatory Bowel Disease: do we measure what we measure?

van Andel, Emma M; Koopmann, Brechtje D M; Crouwel, Femke; Noomen, Casper G; de Boer, Nanne K H; van Asseldonk, Dirk P; Mokkink, Lidwine B

BACKGROUND AND AIMS Patient-reported outcome measures are increasingly important in daily care and research in inflammatory bowel disease (IBD). This study provides an overview of the content and content validity of IBD-specific patient-reported outcome measures on three selected constructs. METHODS Databases were searched up to May 2019 for development and/or content validity studies on IBD-specific self-report measures on health-related quality of life, disability and self-report disease activity in adults. Evidence was synthesized on content validity in three aspects: relevance, comprehensiveness and comprehensibility following the COnsensus-based Standards for the selection of health Measurement INstruments methodology. Questionnaire items were organized in themes to provide an overview of important aspects of these constructs. RESULTS For 14/44 instruments, 25 content validity studies were identified and 25/44 measures had sufficient content validity, the strongest evidence being of moderate quality, though most evidence is of low or very low quality. The Crohn's Life Impact Questionnaire and IBD questionnaire-32 on quality of life, the IBD-Control on disease activity and the IBD Disability Index Self-Report and its 8-item version on disability, have the strongest evidence for sufficient relevance, comprehensiveness and comprehensibility, ranging from moderate to very low evidence. A fair number of recurring items themes, possibly important for the selected constructs was identified. CONCLUSIONS The body of evidence for content validity of IBD-specific health-related quality of life, self-report disease activity and disability self-report measures is limited. More content validity studies should be performed after reaching consensus on the constructs of interest for IBD and studies should involve patients.