Condition-specific Western Ontario McMaster Osteoarthritis Index was not superior to region-specific Lower Extremity Functional Scale at detecting change.
OBJECTIVE
We determined whether the sensitivity to change of the Western Ontario McMaster Osteoarthritis Index (WOMAC) physical function (PF) subscale, a condition-specific measure for persons with osteoarthritis of the hip or knee, was superior to a lower extremity region-specific measure, the Lower Extremity Functional Scale (LEFS), in persons with osteoarthritis of the hip or knee undergoing total joint arthroplasty.


METHODS
The WOMAC and LEFS were administered to 102 patients with osteoarthritis preoperatively, within 16 days of surgery, and >20 days after the first postoperative assessment. These time points enabled the assessment of deterioration and improvement. Two timed performance measures (40 m walk test and the timed-up-and-go test) were also assessed. Change was quantified by the standardized response mean (SRM).


RESULTS
WOMAC PF SRMs were not greater than the LEFS SRMs. Performance measures' times increased significantly over the deterioration interval and decreased over the improvement interval. The WOMAC PF and LEFS demonstrated significant improvement over the second assessment interval; only the LEFS showed significant deterioration over the first assessment interval. WOMAC PF scores seem to be strongly influenced by pain.


CONCLUSIONS
The findings do not support the hypothesis that the WOMAC PF subscale is superior to the LEFS in detecting change.
Stratford
Paul W
PW
School of Rehabilitation Science, McMaster University, 1400 Main St West, Hamilton, Ontario L8S 1C, Canada. stratfor@mcmaster.ca
Kennedy
Deborah M
DM
Hanna
Steven E
SE
D000368:Aged; D019644:Arthroplasty, Replacement, Hip; D019645:Arthroplasty, Replacement, Knee; D005260:Female; D006305:Health Status Indicators; D006621:Hip Joint / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology / Q000601:surgery; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000503:physiopathology / Q000534:rehabilitation* / Q000601:surgery; D020370:Osteoarthritis, Knee / Q000503:physiopathology / Q000534:rehabilitation* / Q000601:surgery; D012680:Sensitivity and Specificity