Table 2.

Univariate analysis biologic agent experience between early onset and late onset groups in ulcerative colitis (N=2017).

Characteristics		Early onset UCa (age at diagnosis <40 years) (N=1015)	Late onset UC (age at diagnosis ≥40 years) (N=1002)	P value
Follow-up period (weeks), mean (SD)		156.90 (156.70)	190.70 (175.80)	.005
Male, n (%)		590 (58.13)	563 (56.19)	.40
Current age (years), mean (SD)		33.60 (10.00)	63.90 (11.10)	<.001
Phenotype of IBDb
	Systemic steroid use at diagnosis, n (%)	131 (12.91)	130 (12.97)	.91
IBD related outcome (biologic agent)
	Age at experience of biologic agent (years), mean (SD)	26.13 (8.81)	54.93(9.42)	<.001
	Experienced biologic agent, n (%)	64 (6.31)	40 (3.99)	<.001
Laboratory data (at diagnosis)
	Hematocrit (%), mean (SD)	39.21 (5.99)	38.71 (5.22)	.32
	Serum albumin (g/dL), mean (SD)	4.19 (0.59)	4.12 (0.51)	<.001
	Serum blood urea nitrogen (mg/dL), mean (SD)	11.09 (3.68)	14.39 (5.48)	<.001
	Serum creatinine (mg/dL), mean (SD)	0.83 (0.42)	1.29 (6.49)	.23
	C-reactive protein (g/dL), mean (SD)	2.01 (3.71)	1.69 (3.59)	.32

^aUC: ulcerative colitis.

^bIBD: inflammatory bowel disease.