Reliability and Validity of the Activity Diversity Questionnaire for Older Adults in Japan.

Recent research has suggested that the breadth and evenness of activity and activity diversity contribute to health outcomes among older adults. However, few established assessment tools for activity diversity have been developed. This study developed an Activity Diversity Questionnaire (ADQ) for older adults through expert consultation and a preliminary survey among 18 community-dwelling older adults. The diversity score was calculated according to Shannon's entropy. In study 1, the intraclass correlation coefficients (ICC) of the diversity scores were determined for community-dwelling older adults (n = 30). In study 2, concurrent validity was tested with participants receiving comprehensive health checkups at the Itabashi ward in Japan in 2018 (n = 766). The correlation coefficients of the diversity scores were then calculated in reference to the Tokyo Metropolitan Institute of Gerontology Index of Competence and Japan Science and Technology Agency Index of Competence. The final version of the ADQ consisted of 20 total items with excellent test-retest reliability (ICC = 0.84) and moderate correlations with both the Tokyo Metropolitan Institute of Gerontology Index of Competence and Japan Science and Technology Agency Index of Competence (r = 0.48 and 0.60, respectively). The ADQ was developed through scientific procedures and revealed sufficient reliability and validity. As such, it is a scientifically validated tool for assessing activity diversity among older adults.