Feasibility, reliability, and validity of the 12-item World Health Organization Disability Assessment Schedule 2.0 in patients attending the pain clinic

Purpose In the cohort of patients attending pain clinic, the primary goal has been shifting from pain reduction to improving activities of daily living and functional status. The 12-item World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) is one of the useful tools for assessment of functional status across all psychiatric and medical diseases; however, its feasibility, reliability, and validity have not been assessed in these patients. Thus, in this study, we evaluated the feasibility, reliability, and validity of the 12-item WHODAS 2.0 in patients attending the pain clinic at our university hospital. Methods This is a prospective observational study including the patients aged 50 years or older who were attending the pain clinic at Nara Medical University between April 2019 and May 2019. Patient-related outcomes including functional status and activities of daily living were assessed with the 12-item WHODAS 2.0, EuroQol-5 dimension 5 levels, and the Tokyo Metropolitan Institute of Gerontology Index. Results The response rate was 99.7%. The 12-item WHODAS2.0 had a floor effect but no ceiling effect and its Cronbach’s α coefficient was 0.909. The correlation coefficients between the 12-item WHODAS 2.0 score and the EuroQol-5 dimension 5 levels and the Tokyo Metropolitan Institute of Gerontology Index were -0.66 and -0.67, respectively. Conclusions The 12-item WHODAS 2.0 is a useful measurement tool to assess disability of pain patients with high reliability and validity.