Smoking increases the risk of extraintestinal manifestations in Crohn's disease

Table 5 Univariate analysis for ulcerative colitis n (%)

Variable	Category (n)	With EIM	Univariate analysis
			P	RR (95%CI)
Sex	Female (46)	17 (37.0)	0.92	0.96 (0.42-2.20)
	Male (50)	19 (38.0)
Pancolitis1	Yes (29)	12 (41.4)	0.49	1.38 (0.55-3.44)
	No (59)	20 (33.9)
Surgery	Yes (6)	5 (83.3)	0.03	9.52 (1.06-85.08)
	No (90)	31 (34.4)
Family history	Yes (5)	1 (20.0)	0.65	0.39 (0.04-3.66)
	No (90)	25 (38.9)
Smoking	Yes (19)	7 (36.8)	0.80	1.14 (0.42-3.13)
	No (77)	29 (37.7)
Age	≤ 40 y (67)	27 (40.3)	0.39	0.67 (0.26-1.68)
	> 40 y (29)	9 (31.0)
Immunosuppressive therapy	Yes (27)	11 (40.7)	0.71	1.18 (0.48-2.95)
	No (68)	25 (36.8)

¹Not applicable in 8 patients. EIM: Extraintestinal manifestation.