Table 1 Summary fit statistics for original and final models for MSIS-29 subscales
From: Rasch analysis of the Multiple Sclerosis Impact Scale (MSIS-29)
Action | Analysis Number | Overall model fit | Item fit Mean (SD) | Person fit Mean (SD) | PSI | % significant t-tests |
|---|---|---|---|---|---|---|
MSIS-29-PHYS | Â | Â | Â | Â | Â | Â |
Original scale | 1 | χ2 = 44.04, df = 20, p = .002 | .31 (1.46) | -.09 (1.33) | .95 |  |
Rescoring to 3-point | 2 | χ2 = 21.59, df = 20, p = .36 | -.12 (1.29) | -.44 (1.64) | .93 |  |
Removal of 1 case | 3 | χ2 = 19.34, df = 20, p = .50 | -.10 (1.19) | -.44 (1.58) | .93 | 9.21% (CI:4–14%) |
MSIS-29-PSYCH | Â | Â | Â | Â | Â | Â |
Original scale | 4 | χ2 = 12.57, df = 9, p = .18 | .09 (1.28) | -.38 (1.58) | .90 |  |
Removal of 1 case | 5 | χ2 = 14.79, df = 8, p = .10 | .10 (1.31) | -.33 (1.49) | .91 | 1.69% |