Psychometric validation of the Chinese version of the Social Integration in Later Life Scale among older adults with disability

Social integration is important for health among older adults with disability, yet validated multidimensional measures remain limited in China. This study aimed to translate and culturally adapt the Social Integration in Later Life Scale (SILLS) and evaluate its psychometric properties among Chinese older adults with disability. The SILLS was translated and culturally adapted following Beaton’s guidelines. Content validity was assessed through expert consultation. Between June and December 2024, 520 older adults with disability were recruited from three rehabilitation hospitals in Changsha, China. The first 212 participants were recruited for item analysis, reliability analysis, and exploratory factor analysis (EFA). The subsequent 308 participants were recruited for confirmatory factor analysis (CFA), convergent validity, and discriminant validity assessment. Floor and ceiling effects were also assessed. The Chinese SILLS retained 18 items across four dimensions. Content validity analysis showed item-level content validity index values of 0.80 to 1.00 and scale-level indices of 0.89 and 0.98. Item analysis supported retention of all items. EFA supported the four-factor structure, and CFA showed acceptable model fit (χ² = 339.47, CFI = 0.995, TLI = 0.995, RMSEA = 0.073, SRMR = 0.042). For convergent validity, composite reliability ranged from 0.920 to 0.982, and average variance extracted from 0.702 to 0.931. For discriminant validity, HTMT values ranged from 0.757 to 0.911; one factor pair marginally exceeded 0.90. Cronbach’s α was 0.897 for the total scale and 0.798 to 0.909 across the subscales. No floor or ceiling effects occurred for the total scale, although the Satisfaction-Interpersonal subscale showed a ceiling effect. The Chinese SILLS demonstrated acceptable reliability and initial evidence of structural validity among older adults with disability. It may provide a multidimensional instrument for assessing social integration in this population.