Reliability and construct validity of the new region-specific PBM AP-7D developed in East and Southeast Asia

Abstract

Background: The AP-7D is a preference-based measure newly developed in East and Southeast Asia. This study aimed to show the psychometric properties of the new instrument. Methods: Surveys were conducted in Japan, Korea, China, Thailand, and Singapore. In each country, 500 respondents were selected by quota sampling and stratified by sex and age. We conducted a face-to-face survey in Japan and a web-based survey in the other countries at two time points. The AP-7D and the EQ-5D-5L were collected from all countries, and the SF-6D was collected only in Japan. The reliability of the instruments was confirmed by comparing responses based on self-report test-retest methods. Regarding construct validity, we compared responses to the AP-7D with those of the EQ-5D-5L and the SF-6D based on predetermined hypotheses. Results: The percentage of agreement between the two surveys was 73.9% (pain/discomfort), 71.2% (anxiety/depression), 68.6% (energy), 89.6% (mobility), 82.1% (work/school), 84.3% (social relations), and 86.4% (burden to others) in five countries. These values were comparable with those of the EQ-5D-5L. The kappa coefficients of the AP-7D items were similar to those of the EQ-5D-5L. According to the correlation matrix between the AP-7D and EQ-5D-5L, correlation exceeded 0.5 in the following items: 0.69 between “mental health” (AP-7D) and “anxiety/depression” (EQ-5D-5L), 0.54 between both “pain/discomfort,” 0.51 between “energy” (AP-7D) and “anxiety/depression” (EQ-5D-5L), and 0.50 between both “mobility.” Conclusion: The survey results showed good reliability and construct validity of the AP-7D. Basic psychometric properties of the new instrument were confirmed.