Cross-cultural adaptation and psychometric evaluation of the social frailty scale in Iranian older adults

Abstract Background Social frailty is a holistic concept encompassing various social determinants of health. Considering its importance and impact on health-related outcomes in older adults, the present study was conducted to cross-culturally adapt and psychometrically evaluate the Social Frailty Scale in Iranian older adults in 2023. Methods This was a methodological study. The translation and cross-cultural adaptation of the Social Frailty Scale 8-item (SFS-8) was conducted according to Wild’s guideline. Content and face validity were assessed using qualitative and quantitative methods. Then, 250 older adults covered by comprehensive health centers were selected using multistage random sampling. Participants completed the demographic questionnaire, the Abbreviated Mental Test score, the SFS-8, and the Lubben Social Network Scale. Construct validity was assessed by principal component analysis (PCA) and known-group comparisons. The Mann‒Whitney U test was used to compare social frailty scores between the isolated and non-isolated older adults. Internal consistency, equivalence, and stability were assessed using the Kuder-Richardson method, the intraclass correlation coefficient (ICC), the standard error of measurement (SEM), and the minimum detectable change (MDC). The ceiling and floor effects were also assessed. The data were analyzed using JASP 0.17.3. Results The ratio and index of content validity and the modified kappa coefficient of all the items were 1.00. The impact score of the items was greater than 4.6. PCA identified the scale as a single component by removing two questions that could explain 52.9% of the total variance in the scale score. The Persian version of the Social Frailty Scale could distinguish between isolated and non-isolated older adults (p < 0.001). The Kuder–Richardson coefficient, ICC, SEM, and MDC were 0.606, 0.904, 0.129, and 0.358, respectively. The relative frequencies of the minimum and maximum scores obtained from the scale were 34.8 and 1.2, respectively. Conclusions The Persian version of the Social Frailty Scale (P-SFS) can be used as a valid and reliable scale to assess social frailty in Iranian older adults.