Adaptation and validation of WHODAS 2.0 in patients with musculoskeletal pain

OBJECTIVE: To validate the Portuguese version of the World Health Organization Disability Assessment Schedule (WHODAS 2.0). METHODS: The original, 36 item version of the WHODAS 2.0, administered through an interview, was translated into Portuguese following international guidelines and tested on 9 participants from the general population. The Portuguese version was then administered to 204 patients with musculoskeletal pain. The patients' socio-demographic and health data were collected, as were the number of sites where they were experiencing pain and the intensity of that pain. The WHODAS 2.0 was administered again by a second interviewer within three days to determine its inter-rater reliability. Construct validity was assessed according to the ability of WHODAS 2.0 to discriminate between patients with different numbers of pain sites and the correlation between WHODAS 2.0 scores and pain intensity. Internal consistency was also assessed. RESULTS: The Portuguese version of the WHODAS 2.0 is easily understood and has good internal consistency (a = 0.84), as well as, very good inter-rater reliability (ICC = 0.95). In addition, it was able to detect statistically significant differences between patients with different numbers of pain sites (p < 0.01) and showed that higher levels of disability are associated with more intense pain (r = 0.44, p < 0.01), indicating that it has construct validity. CONCLUSIONS: The Portuguese version of the WHODAS 2.0 has shown to be reliable and valid when administered to patients with musculoskeletal pain.