A Comparison of a Modified Oswestry Low Back Pain Disability Questionnaire and the Quebec Back Pain Disability Scale

The construct validity of the global rating of change was supported by the stability of the Physical Impairment Index across the study period in patients defined as stable by the global rating and by the decrease in physical impairment across the study period in patients defined as improved by the global rating. The modified OSW demonstrated superior measurement properties compared with the QUE.