Table 3.

Univariate Analysis of biologic agent experience between early onset and late onset group in Crohn's disease (N=1463).

Characteristics		Early onset CDa (age at diagnosis <40 years) (N=1059)	Late onset CD (age at diagnosis ≥40 years) (N=404)	P value
Follow-up period (weeks), mean (SD)		106.29 (125.91)	163.48 (155.93)	<.001
Male, n (%)		728 (68.74)	211 (52.23)	<.001
Current age (years), mean (SD)		28.81 (9.69)	63.32 (12.11)	<.001
Phenotype of IBDb
	Systemic steroid use at diagnosis, n (%)	144 (13.60)	39 (9.65)	.04
IBD related outcome (biologic agent)
	Age at experience of biologic agent (years), mean (SD)	23.48 (8.53)	54.09 (10.32)	<.001
	Experience of biologic agent, n (%)	144 (13.60)	33 (8.17)	<.001
Laboratory data (at diagnosis)
	Hematocrit (%), mean (SD)	38.91 (5.18)	36.72 (6.34)	.001
	Serum total bilirubin (mg/dL), mean (SD)	0.62 (0.39)	0.74 (0.42)	.04
	Serum albumin (g/dL), mean (SD)	4.11 (0.57)	4.02 (0.63)	.31
	Serum creatinine (mg/dL), mean (SD)	0.73 (0.42)	1.14 (1.27)	.007
	C-reactive protein (g/dL), mean (SD)	3.69 (4.01)	2.2 (3.99)	.59

^aCD: Crohn’s disease.

^bIBD: inflammatory bowel disease.