Psychometric Properties of the Polish Version of the 36-Item WHODAS 2.0 in Patients with Low Back Pain

The World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) is considered by the World Health Organization (WHO) to be a useful tool for assessing the functioning and disability of the general population as well as the effectiveness of the applied interventions. Until this study, no data regarding the validity of the 36-item WHODAS 2.0 in chronic low back pain (LBP) in Poland have been explored. This study was conducted on 92 patients suffering from chronic LBP admitted to the rehabilitation ward. The Polish version of the 36-item WHODAS 2.0, the Sf-36 Health Survey (SF-36), the Oswestry Disability Index (ODI), the Hospital Anxiety and Depression Scale (HADS) and the Visual Analogue Scale (VAS) questionnaires were applied to assess patients. The scale score reliability of the entire tool for the study population was very high. The Cronbach's alpha test result for the entire scale was 0.92. For the overall result of the WHODAS 2.0, the Intraclass Correlation Coefficient (ICC1,2) was 0.928, which confirmed that the scale was consistent over time. The total result and the vast majority of domains of the 36-item WHODAS 2.0 correlated negatively with domains of the SF-36 questionnaire; thus, a higher WHODAS 2.0 score was associated with a lower score on the SF-36 questionnaire. We found that the minimal clinically important difference (MCID) for the total WHODAS 2.0 score in patients after rehabilitation for LBP was 4.87. Overall, the results indicated that the Polish version of the 36-item WHODAS is suitable for assessing health and disability status in patients with LBP.