Epidemiology and clinical course of Crohn's disease: Results from observational studies

Table 1 Cumulative rate (Cum %) of CD patients with relapsing disease during the first year and in the periods 1-5 and 5-10 years after diagnosis (Solberg et al[30], with permission)

		Relapse during the 1st year		Relapse between 1-5 yr		Relapse between 5-10 yr
Variables at diagnosis	Total in each subgroup	cum%(CI)	P value	cum%(CI)	P value	cum%(CI)	P value
Age groups
A1 < 40 yr	148	54 (50-58)	0.7	80 (77-83)	0.6	61 (57-65)	0.03
A2 ≥ 40 yr	49	51 (44-58)		76 (70-82)		43 (36-50)
Gender
Female	95	54 (49-59)	0.9	76 (72-80)	0.4	56 (51-61)	0.9
Male	102	53 (48-58)		81 (77-85)		57 (52-62)
Location
L1: Terminal ileum	51	54 (47-61)	0.4	78 (72-84)	0.8	57 (50-64)	0.1
L2: Colon	94	57 (52-64)		76 (72-80)		49 (44-54)
L3: Ileocolon	48	44 (37-51)		81 (75-87)		69 (62-76)
L4: Upper GI	4	75 (53-97)		100 (-)		75 (53-97)
Behavior
B1: Inflammatory	127	56 (52-60)	0.7	79 (75-83)	0.6	54 (50-58)	0.4
B2: Stricturing	50	49 (42-56)		74 (68-78)		64 (57-71)
B3: Penetrating	20	50 (39-61)		85 (77-93)		55 (44-66)
Systemic steroids
No	86	47 (42-52)	0.08	69 (64-74)	0.008	47 (42-52)	0.02
Yes	109	59 (54-64)		85 (82-88)		63 (58-68)
Missing	2	-		-		-
Smoking status
Never	82	52 (47-57)	0.5	79 (75-84)	0.9	59 (54-64)	0.09
Current smoker	82	57 (52-62)		79 (75-84)		61 (56-66)
Ex-smoker	29	45 (36-54)		76 (68-84)		38 (29-47)
Missing	4	-		-		-
Total	197	54 (50-57)		79 (76-82)		56 (53-60)

χ² comparisons within each subgroup; CI: Confidence interval; GI: Gastrointestinal.

Table 2 Risk factors at diagnosis associated with surgery during follow-up analyzed by Cox regression (Solberg et al[30], with permission)

			Unadjusted			Adjusted
Variables at diagnosis	Number in analysis	Number with surgery (%)	HR	95% CI	P value	HR	95% CI	P value
Age
A1: < 40 yr	165	69 (42)	1	[Ref]	0.03	1	[Ref]	0.03
A2: ≥ 40 yr	72	16 (22)	0.5	0.3-0.9		0.5	0.3-0.9
Gender
Female	118	40 (34)	1	[Ref]	0.9	Not included
Male	119	45 (38)	1	0.7-1.6
Location
L1: Terminal ileum	64	38 (59)	1	[Ref]	< 0.001	1	[Ref]
L2: Isolated colonic	115	26 (23)	0.2	0.1-0.4		0.3	0.2-0.6	0.001
L3: Ileocolon	54	17 (32)	0.3	0.2-0.6		0.3	0.2-0.5	< 0.001
L4: Upper GI1	4	4 (100)	1.4	0.5-3.8		1.6	0.5-4.4	0.4
Behavior
B1: Inflammatory	147	32 (22)	1	[Ref]	< 0.001	1	[Ref]
B2: Stricturing	64	36 (56)	3.5	2.1-5.6		2.3	1.3-4.1	0.004
B3: Penetrating	26	17 (65)	4.9	2.7-8.8		5.4	3.0-9.9	< 0.001
Smoking status2
Never	103	38 (37)	1	[Ref]	0.2	Not included
Current < 10 cigarettes/d	57	18 (32)	0.8	0.4-1.4
Current > 10 cigarettes/d	36	18 (50)	1.9	0.8-2.6
Ex-smoker	35	11 (31)	0.8	0.4-1.6
Systemic steroids3
No	106	36 (34)	1	[Ref]	0.8	Not included
Yes	129	48 (37)	1.1	0.7-1.6

¹Difficult to conclude because of an insufficient number of patients;

²data unknown in 6 cases. There were none in the operated group;

³data unknown in 2 cases; There was one in the operated group. Ref: Reference variable; HR: Hazard ratio; CI: Confidence interval.