Rasch analysis of the Multiple Sclerosis Impact Scale (MSIS-29)

Table 2 Individual item fit statistics for the 20-item MSIS-29-PHYS

Item	MSIS Item name	Location	SE	Fit Resid	Chi Sq	Prob
1	Do physically demanding tasks	-2.239	0.254	0.382	0.632	0.427
2	Grip things tightly (e.g. turning on taps)	0.219	0.201	0.453	1.509	0.219
3	Carry things	-0.788	0.235	0.361	0.138	0.710
4	Problems with your balance	-0.481	0.279	0.747	0.259	0.611
5	Difficulties moving about indoors	1.682	0.256	0.294	0.156	0.693
6	Being clumsy	0.061	0.278	-1.097	2.381	0.123
7	Stiffness	0.009	0.233	-0.200	0.424	0.515
8	Heavy arms and/or legs	-0.258	0.218	-0.758	0.089	0.765
9	Tremor of your arms or legs	0.696	0.213	1.356	1.091	0.296
10	Spasms in your limbs	0.723	0.222	0.574	0.375	0.540
11	Your body not doing what you want it to do	-0.577	0.204	-0.669	0.115	0.734
12	Having to depend on others to do things for you	-0.102	0.219	-1.681	2.116	0.146
13	Limitations in your social and leisure activities at home	0.515	0.234	-0.938	4.469	0.035
14	Being stuck at home more than you would like to be	0.022	0.196	-0.721	0.148	0.701
15	Difficulties using your hands in everyday tasks	0.669	0.219	-0.268	0.384	0.536
16	Having to cut down the amount of time you spent on work or other daily activities	-0.096	0.215	-0.702	0.033	0.855
17	Problems using transport (e.g. car, bus, train, taxi, etc.)	0.639	0.199	-0.916	0.258	0.611
18	Taking longer to do things	-0.200	0.239	-0.884	0.086	0.770
19	Difficulty doing things spontaneously (e.g. going out on the spur of the moment)	-0.075	0.206	-1.117	0.025	0.875
20	Needing to go to the toilet urgently	-0.419	0.196	3.715	4.649	0.031

Values showing significant misfit bolded.
SE = Standard error, Fit Resid = Fit Residual, Chi-Sq = Chi-Square, Prob = probability
Fit Residual df = 82.6, Chi-square df = 1