Comparing different revisions of the Childhood Health Assessment Questionnaire to reduce the ceiling effect and improve score distribution: Data from a multi-center European cohort study of children with JIA

Table 2 Score distribution characteristics of the five CHAQ versions.

CHAQ Version	Median (range)	% at ceiling	KS-statistic	p	IQR	Skewness	Kurtosis
CHAQ30orig	0.38 (0-2.13)	27*	0.19	<0.001	1.06	0.85	-0.51
CHAQ30CATI	0.10 (0-1.62)^{a, c}	27*	0.22	<0.001	0.40	1.62	2.65
CHAQ38CATI	0.19 (0-1.84)^{a, b}	14	0.19	<0.001	0.49	1.42	1.69
CHAQ30CATII	-0.033 (-1.69-2)^e	1	0.24	<0.001	0.35	0.94	5.43
CHAQ38CATII	-0.12 (-1.7-1.76)^d	0	0.20	<0.001	0.45	0.72	3.60

* ceiling effect, > 15% at ceiling; IQR: Interquartile range, KS: Kolmogorov Smirnov; p: probability value of the KS one sample test of normality.
^a significantly different from CHAQ30orig, Wilcoxon p < 0.001
^b significantly different from CHAQ30CATI, Wilcoxon p < 0.001
^c significantly different from CHAQ38CATI, Wilcoxon p < 0.001
^d significantly different from CHAQ30CATII, Wilcoxon p < 0.001
^e significantly different from CHAQ38CATII, Wilcoxon p < 0.001

ISSN: 1546-0096