Convergent validity of 12-item World Health Organization Disability Assessment Schedule (WHODAS 2.0) among people with neck pain

Most of the items and the composite scores of the WHODAS and the NDI demonstrated significant positive correlations. Pain intensity, as defined by the NDI, did not correlate with disability severity measured by the WHODAS 2.0. Also, the NDI items 'headaches' and 'sleeping' were associated with the WHODAS 2.0 only loosely. It seems that one of these two scales may not directly be substituted by another. When used simultaneously, The WHODAS and the NDI may complement each other covering comprehensively the different dimensions of functioning among people with neck pain.