From: The Visual Analogue WOMAC 3.0 scale - internal validity and responsiveness of the VAS version
Analysis number | Item fit residual | Person fit residual | χ2 interaction | PSI | Uni-dimensionality Independent t-test (95% CI) | |||
---|---|---|---|---|---|---|---|---|
Pain subscale | Mean | SD | Mean | SD | Value (df) | P* | Â | Â |
Pre-data | Â | Â | Â | Â | Â | Â | Â | Â |
   Analysis 1 | 0.538 | 1.101 | -0.433 | 1.224 | 5.65 (10) | 0.844 | 0.86 | 6.3% (3.5 to 9.2) |
   Analysis 2 | -0.065 | 2.811 | -0.538 | 1.194 | 8.15 (8) | 0.419 | 0.85 | 4.5% (1.7 to 7.4) |
Physical Functioning subscale | ||||||||
   Analysis 3 | 0.478 | 1.511 | -0.557 | 1.896 | 63.37 (34) | 0.002 | 0.96 | 9.5% (6.6 to 12.4) |
   Analysis 4 | 0.757 | 1.393 | -0.469 | 1.823 | 44.81 (32) | 0.066 | 0.96 | 7.7% (4.8 to 10.6) |
Stiffness subscale | ||||||||
   Analysis 5 | -0.546 | 0.181 | -0.499 | 0.722 | 8.61 (4) | 0.072 | 0.81 | 2.3% (-0.6 to 5.2) |