Protective effect of appendectomy against the onset of ulcerative colitis: A case-control study

Table 1 General clinical data of patients, n (%)/mean ± SD

	UC (n = 313)	Non-UC (n = 313)	t/χ2	P value
Age	42.50 ± 13.94	41.84 ± 13.71	0.590	0.556
Sex			0.058	0.810
Male	176 (56.23)	173 (55.27)
Female	137 (43.77)	140 (44.73)
Nationality			29.344	< 0.001
Han	159 (50.8)	225 (71.88)
Ethnic minorities	154 (49.2)	88 (28.12)
Education level			2.334	0.127
Low and middle education	183 (58.47)	164 (52.40)
Higher education	130 (41.53)	149 (47.60)
Region of residence			8.395	0.004
Urban	214 (68.37)	246 (78.59)
Rural	99 (31.63)	67 (21.41)
Smoking history			6.157	0.013
Smoking	58 (18.53)	84 (26.84)
No smoking	255 (81.47)	229 (73.16)
Drinking history			10.102	0.001
Drinking	43 (13.74)	74 (23.64)
No drinking	270 (86.26)	239 (76.36)
History of appendectomy			37.541	< 0.001
Appendectomized	43 (13.74)	3 (0.96)
Nonappendectomized	270 (86.26)	310 (99.04)

UC: Ulcerative colitis.