Risk factors and long-term prognosis for colorectal strictures in ulcerative colitis

Table 4 Univariate and multivariate Cox regression analysis of risk factors for colorectal stricture formation in ulcerative colitis¹

Variables	Univariate		Multivariate
	HR (95%CI)	P value	HR (95%CI)	P value
Male	0.896 (0.621-1.293)	0.557
Age at diagnosis ≥ 40 year	2.273 (1.562-3.308)	< 0.001	2.197 (1.487-3.242)	< 0.001
Montreal classification		0.079		0.228
E1 (proctitis)	1		1
E2 (left-sided colitis)	0.555 (0.319-0.963)	0.036	0.610 (0.347-1.073)	0.087
E3 (pancolitis)	0.846 (0.525-1.362)	0.491	0.780 (0.478-1.275)	0.322
Extraintestinal involvement	2.077 (1.346-3.205)	< 0.001	2.072 (1.326-3.239)	0.001
Hemoglobin	0.986 (0.979-0.992)	< 0.001	0.988 (0.980-0.995)	0.001
CRP	1.007 (1.002-1.011)	0.003	1.004 (0.999-1.010)	0.145
ESR	1.008 (1.001-1.015)	0.028	0.995 (0.986-1.004)	0.301
Treatment until stricture or the end of follow-up
5-ASA	0.406 (0.163-1.012)	0.053	0.214 (0.077-0.595)	0.003
Systemic glucocorticoids	1.895 (1.145-3.135)	0.013	2.360 (1.325-4.203)	0.004
Immunomodulators	0.985 (0.654-1.482)	0.942
Anti-TNF-α	0.764 (0.450-1.298)	0.320	0.911 (0.517-1.604)	0.746
VDZ	0.370 (0.199-0.689)	0.002	0.382 (0.203-0.720)	0.003
UST	0.049 (0.0-5887.28)	0.614	0.000(0.0-2.4E+163)	0.961

¹Model assumptions were validated: Proportional hazards assumption satisfied (global P = 0.274), and multicollinearity absent (all variance inflation factor < 2.5).

HR: Hazard ratio; CI: Confidence interval; CRP: C-reactive protein; ESR: Erythrocyte sedimentation rate; 5-ASA: 5-aminosalicylic; anti-TNF-α: Anti-tumor necrosis factor-α; VDZ: Vedolizumab; UST: Ustekinumab.