Validation of the World Health Organization Assessment Schedule II Chinese Traditional Version (WHODAS II CT) in persons with disabilities and chronic illnesses for Chinese population.

Purpose: The aim of this study is to test the psychometric properties and validity of the World Health Organization Assessment Schedule II Chinese Traditional Version (WHODAS II CT) in Traditional Chinese-speaking persons with disabilities and chronic illnesses. Method: The WHODAS II CT has been administrated to a sample of 1020 persons with disabilities and chronic illnesses. The construct validity, internal consistency, concurrent validity and convergent validity were evaluated. Results: WHODAS II CT showed a satisfactory model fit for the second-order confirmatory factor analysis model (chi(2)/df = 3.05, root means square error of approximation =0.053, comparative fit index =0.912, standardized root mean square residual =0.076), high internal consistency (Cronbach's alpha = 0.98), high correlation with all domains of Dartmouth Primary Care Cooperative Research Network/World Organization of National Colleges, Academies, and Academic Associations of General Practices/Family Physicians (COOP/WONCA) charts (partial correlation coefficient ranged from 0.26 to 0.74) and significance between persons with and without co-morbidity (all regression coefficients>0). Conclusions: WHODAS II CT is a reliable and valid instrument to measure the disability in persons with disabilities and chronic illnesses among Traditional Chinese-speaking population. A further study is required to validate the short version of WHODAS II in order to enhance its applicability in usual and clinical practices.