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Table 2 Test-of-fit for two models using conditional likelihood ratio tests and comparing estimates of item thresholds in groups defined by different test criteria

From: Item analysis using Rasch models confirms that the Danish versions of the DISABKIDS® chronic-generic and diabetes-specific modules are valid and reliable

Test criterion A: Rasch model–six items B: Graphical log linear Rasch modela–five items
CLR Df P CLR df p
Low and high score groups 47.6 22 .001 34.3 33 .407
HbA1c 54.5 44 .133 90.0 66 .026
Treatment 42.3 22 .006 49.8 33 .030
Age 68.7 44 .010 65.3 44 .020
Sex 32.3 22 .072 36.6 33 .306
Inclusion or follow-up 22.9 22 .405 35.5 33 .350
  1. The pure Rasch model is rejected because of local dependency between items 1 and 3 and because it operates differently for different age groups and treatments; however, it is improved when item 6 is excluded and GLLRM is applied allowing for local dependency between items 1 and 3 and DIF in relation to age
  2. aThe model assumes that items 1 and 3 are locally dependent and that item five is affected by DIF depending on age