Measuring subjective aspects of participation in adults with disabilities: A systematic review of the coverage, content validity and internal structure of standardised instruments.

Objective: To systematically review evidence on the coverage, content validity and internal structure of self-report measures capturing subjective aspects of participation for adults with disabilities.
Data Sources: EMBASE, MEDLINE and reference lists were searched until July 10 ^th , 2022 for articles on measurement properties of instruments measuring participation as defined in the International Classification of Functioning, Disability and Health, from a subjective perspective.
Method: Each instrument was assessed for its coverage of subjective aspects of participation. The Consensus-based Standards for the Selection of Health Measurement Instruments were used to assess the quality of each study. Content validity and internal structure (structural validity, internal consistency and cross-cultural validity) were rated against published standards and qualified by the adapted Grading of Recommendations Assessment, Development and Evaluation.
Results: Thirty-eight studies regarding 10 instruments were analysed. Most instruments mix activity and participation items. Only the Measure of Experiential Aspects of Participation (with high-quality evidence of sufficient structural validity and generally sufficient internal consistency), the Participation Enfranchisement and the Community Integration Measure showed adequate coverage. For all instruments, evidence of content validity is of low- to very low quality. There is high-quality evidence that the Participation Scale is not unidimensional.
Conclusion: In general, the coverage and the evidence for content validity and internal structure of measures capturing experiential aspects of participation are limited. The Measure of Experiential Aspects of Participation has the best level of evidence in support of its use. The score of the Participation Scale cannot be considered an adequate reflection of participation.