Validity and reliability of the Checklist for Habitual Physical Activity for people 75 years and older in Japan

Abstract Background Despite health benefits, many older adults struggle to meet physical activity guidelines, leading to stagnant activity levels. While integrating physical activity into daily routines has been proposed as a promising strategy for older adults, fit‐for‐purpose measurement tools to assess such routines are lacking. The Checklist for Habitual Physical Activity (CHaPA) was developed based on the positive deviance approach and socio‐ecological model to assess daily behaviours encouraging physical activity among adults aged 75 and older. It has been confirmed for its content and face validity. However, to ensure its broader applicability and usefulness, assessing its construct validity and reliability is necessary. Therefore, this study aims to assess the construct validity and reliability of the CHaPA and accordingly update the tool. Methods To validate the construct validity of the CHaPA 22‐item version, we conducted item analysis and exploratory and confirmatory factor analyses. We removed inappropriate items based on predefined criteria. Then, we assessed the reliability, internal consistency, test–retest reliability, and measurement errors of the CHaPA final version. Results Item analyses and factor analyses resulted in the deletion of 11 items. The results of confirmatory factor analysis validated the CHaPA 11‐item version with the three‐factor structure based on model fit index with χ 2 /degree of freedom = 1.25, comparative fit index = 0.965, Tucker‐Lewis index = 0.952, and root‐mean‐square error of approximation = 0.038. Omega coefficient (0.90) showed excellent internal consistency. Intraclass correlation coefficient (ICC) demonstrated good test–retest reliability (ICC (1, 2) = 0.77, 95% CI = 0.34–0.89, standard error of measurement = 1.75). Conclusions We finalised the CHaPA 11‐item version as a valid and reliable instrument for assessing daily behaviours conducive to physical activity among individuals aged 75 years and older. We need to examine the methods and effectiveness of disseminating this checklist to ensure its utilisation as a resource for promoting healthy ageing and aiding older adults in maintaining active lifestyles.