Development and Psychometric Testing of the Healthy Aging Instrument

The purpose of this study was to develop, refine, and evaluate the psychometric properties of the Healthy Aging Instrument (HAI). The HAI is a multidimensional instrument that attempts to measure the process of healthy aging in a Thai context. Themes emerged from focus groups and in-depth interviews, which were used to develop an item pool. The HAI was reviewed for content format by five experts and for clarity and readability by 10 older adults. The content validity index among the experts was high. After the pretest, the HAI consisted of 46 items. To test construct validity and internal consistency, the HAI was completed by 403 Thai older adults in a Province of Southern Thailand. Evaluation of construct validity through principal component factor analysis with varimax rotation and using factor loading greater than .40 yielded 9 factors and 35 items: 1) Being Self-Sufficient and Living Simply, 2) Managing Stress, 3) Having Social Relationships and Support, 4) Making Merit and Good Deeds, 5) Practicing Self-Care and Self-Awareness, 6) Staying Physically Active, 7) Staying Cognitively Active, 8) Having Social Participation, and 9) Accepting Aging, which jointly explained 62% of the variance in the process of healthy aging. Cronbach's alpha for each of the subscales ranged from .69 to .80 and the overall HAI was .88. The HAI demonstrated adequate internal consistency reliability and showed evidence of content and construct validity. The instrument requires less than 15 minutes on average to administer and had no item-level missing data rates. These findings suggest that the HAI adequately captures a newly identified construct and should be useful for investigators to measure healthy aging in a Thai context. However, the HAI was developed from older adults only in a province of Southern Thailand, thus, the issue of culture and context should be considered for implication of this instrument.