WHODAS 2.0 ̵̵ 36 items
To evaluate the criterion validity of the Chinese version of the Scales, we used the Chinese version of the WHODAS 2.0-36 items. A 5-point Likert scale is used by participants to answer questions related to difficulties performing activities. The score ranges from 0 (lowest difficulty) to 100 (maximum difficulty) and is calculated as the sum of each domain score.22 The higher the score is, the higher the degree of disability and the more severe the restricted situation. Restriction severity refers to the difficulty level classification method of the ICF and WHODAS 2.0. The classification of impairment severity is as follows: below 4% is none; 5-24% is mild; 25-49% is moderate; 50-95% is severe; and more than 96% is extremely severe.23 In this study, only 32 items were calculated because all the participants were retired and unemployed. Among the reliability indices of the Chinese version of the WHODAS 2.0, Cronbach’sα for internal consistency is .70-.99, and the intra-class correlation coefficient is .80-.89.24,25 Among the validity indices, the content and the concurrent validity have some correlation, and based on exploratory factor analyses (EFAs), 5-7 factors have an explanatory power higher than 55%. The factor loadings of the CFA are all higher than .56.24 It has excellent reliability and validity and is consistent with the item response theory (IRT).