Development and psychometric testing of the active aging scale for Thai adults

Background: Active aging is central to enhancing the quality of life for older adults, but its conceptualization is not often made explicit for Asian elderly people. Little is known about active aging in older Thai adults, and there has been no development of scales to measure the expression of active aging attributes. Purpose: The aim of this study was to develop a culturally relevant composite scale of active aging for Thai adults (AAS-Thai) and to evaluate its reliability and validity. Methods: Eight steps of scale development were followed: 1) using focus groups and in-depth interviews, 2) gathering input from existing studies, 3) developing preliminary quantitative measures, 4) reviewing for content validity by an expert panel, 5) conducting cognitive interviews, 6) pilot testing, 7) performing a nationwide survey, and 8) testing psychometric properties. In a nationwide survey, 500 subjects were randomly recruited using a stratified sampling technique. Statistical analyses included exploratory factor analysis, item analysis, and measures of internal consistency, concurrent validity, and test-retest reliability. Results: Principal component factor analysis with varimax rotation resulted in a final 36-item scale consisting of seven factors of active aging: 1) being self-reliant, 2) being actively engaged with society, 3) developing spiritual wisdom, 4) building up financial security, 5) maintaining a healthy lifestyle, 6) engaging in active learning, and 7) strengthening family ties to ensure care in later life. These factors explained 69% of the total variance. Cronbach's alpha coefficient for the overall AAS-Thai was 0.95 and varied between 0.81 and 0.91 for the seven subscales. Concurrent validity and test-retest reliability were confirmed. Conclusion: The AAS-Thai demonstrated acceptable overall validity and reliability for measuring the multidimensional attributes of active aging in a Thai context. This newly developed instrument is ready for use as a screening tool to assess active aging levels among older Thai adults in both community and clinical practice settings.