[Validity and Reliability of the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) in Turkish...

The present study aimed to investigate psychometric properties of a series of disability scores obtained from Turkish version of the WHODAS 2.0 interviewer-, self- and proxy-administered forms consisting of either 36 items or 12 items.

Following the translation, 35 patients with a psychiatric diagnosis and 35 healthy controls between 18 and 65 years of age selfrated their functional impairment on the WHODAS. In addition, each participant was rated by a relative and by one or two clinicians on the pertinent WHODAS forms. In order to collect evidence for validity and reliability of WHODAS general disability and domain scores, we employed a series of Student's t-tests, ROC analyses, logistic regression analyses, intraclass and Pearson's correlation analyses, Cronbach's alpha and item-total statistics.

Regarding general disability scores, in both clinical sample and healthy controls, all three types of 36-item WHODAS displayed satisfactory or higher validity and reliability coefficients. On the other hand, for 12-item version, only the interviewer-rated form demonstrated satisfactory results only in the clinical sample. Domain disability scores yielded by the 36-item forms were generally associated with adequate or acceptable coefficients in the clinical sample, while the coefficients were unacceptable in the control group.

The 36-item WHODAS interviewer-, proxy- and self-rated forms are suitable to assess general disability in Turkish mental health consumers and in healthy subjects. Among the 12-item WHODAS forms, the interviewer-rated form emerges as the sole instrument with comparable validity and reliability for measuring general disability in psychiatric patients. The domain disability scores derived from the long form and general disability scores derived from the short form is suitable for evaluating clinical subjects, but not healthy subjects.