Development and Validation of the COM-B Physical Activity Questionnaire (COM-B PAQ)

Background To provide researchers and practitioners with evidence-based tools for identifying less active individuals and, in turn, help implement more effective physical activity interventions, a need exists to develop valid and reliable measurement tools. The COM-B model, which conceptualises behaviour as the interaction of Capability, Opportunity, and Motivation, provides a framework for understanding physical activity. Importantly, the COM-B guides intervention design through the Behaviour Change Wheel and Behaviour Change Technique Taxonomy. This study therefore aimed to develop and validate a questionnaire that assesses perceived Capability, Opportunity, and Motivation to be physically active, grounded in the Theoretical Domains Framework, with its domains mapped onto COM-B constructs. Methods Development and validation occurred over four studies: (1) item generation and assessing content and face validity ( n  = 9); (2) assessment of model fit ( n  = 491); (3) confirming convergent, discriminant, and predictive validity ( n  = 349); and (4) establishing test-retest reliability ( n  = 58). Results In study 1, an initial item pool consisted of 106 items, which was refined to 59 through expert review and pilot testing. In study 2, confirmatory factor analysis resulted in three models representing three subscales: Capability, Opportunity and Motivation, each comprising 15 factors aligned with the Theoretical Domains Framework, resulting in a final 37-item questionnaire. In Study 3, he questionnaire demonstrated strong concurrent validity, with significant positive correlations with similar established measures, and Study 4 confirmed the test-retest reliability. Conclusion The COM-B PAQ is a psychometrically robust, valid, and reliable questionnaire with good discriminative capacity. It offers researchers and practitioners a new evidence-based tool to assess perceived barriers and enablers to physical activity, supporting the design of tailored and targeted interventions.