How has the disease course of pediatric ulcerative colitis changed throughout the biologics era? A comparison with the IBSEN study

Table 4 Univariable and multivariable analysis of the association between relapse rate and other factors

Parameter	Univariable analysisb				Multivariable analysisb
	Pr > ChiSq	HR	95%CIc of HR		Pr > ChiSq	HR		95%CIc of HR
Age at diagnosis, yr (< 10 yr)	0.063	0.434	0.642	3.714
Disease extent at diagnosis	0.317
E2	1	0.786	0.194	3.185a
E3	1	1.097	0.555	2.166a
E4	0.374	1.758	1.058	2.921a
Corticosteroid uses at baseline (Yes)	0.010	2.111	1.201	3.712	0.109	1.682	0.890		3.176
Mayo endoscopic subscore at diagnosis (> 2 Moderate)	< 0.001	2.496	1.478	4.217	0.015	2.108	1.157		3.843
PUCAId at diagnosis (> 45)	0.558	1.202	0.650	2.222

^aP value and 95%CI for hazard ratio were corrected by Bonferroni's method due to multiple testing.

^bCox’s proportional hazard regression using counting process.

^cThe robust sandwich covariance estimate was used to account for the within-subject correlation.

^dPediatric Ulcerative Colitis Activity Index (PUCAI) is a 6-item disease activity index intended for use in pediatric UC clinical trials with a score ranging from 0-85.

CI: Confidence interval; HR: Hazard ratio.