Table 3.

Summary Fit Statistics for Rasch analyses

	Item residual		Person residual		Chi-Square fit statistic		Reliability		Unidimensionality
	Mean	SD	Mean	SD	Value and (df)	P	PSI	Alpha	t-test; % (95% CI) < 5%
Results	-0.47	0.47	-0.08	0.01	59.4 (45)	0.074	0.90	0.94	2.2% (0.2 – 4.7)
Ideal values	0	1.0	0	1.0		0.003a	> 0.7	> 0.7	< 5.0%

^a: Bonferonni adjustment alpha level for the DEMMI scale with 15 items (0.05/15); SD standard deviation, df degrees of freedom, PSI Person-item separation index, CI confidence interval