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

Table 7 Comparison of clinical data between two groups, n (%)/mean ± SD

	Appendectomized (n = 43)	Non-appendectomized (n = 270)	t/χ2	P value
Age	49.51 ± 14.16	41.38 ± 13.61	-3.621	< 0.001
Sex			1.107	0.293
Male	21 (48.84)	155 (57.41)
Female	22 (51.16)	115 (42.59)
Nationality			7.716	0.007
Han	30 (69.77)	129 (47.78)
Ethnic minorities	13 (30.23)	141 (52.22)
Region of residence			7.202	0.007
Urban	37 (86.05)	177 (65.56)
Rural	6 (13.95)	93 (34.44)
Education level			0.509	0.476
Low and middle education	23 (53.49)	160 (59.26%)
Higher education	20 (46.51)	110 (40.74%)
Smoking history			0.167	0.682
Smoking	7 (16.28)	51 (18.89)
No smoking	36 (83.72)	219 (81.11)
Drinking history			1.923	0.166
Drinking	3 (6.98)	40 (14.81)
No drinking	40 (93.02)	230 (85.19)
Degree of disease activity			48.739	< 0.001
Clinical remission	4 (9.3)	4 (1.48)	9.109	0.003
Mild	22 (51.16)	36 (13.33)	35.162	< 0.001
Moderate	16 (37.21)	178 (65.93)	12.981	< 0.001
Severe	1 (2.33)	52 (19.26)	7.562	0.006
Scope of lesions			21.631	< 0.001
E1	13 (30.23)	29 (10.74)	12.130	< 0.001
E2	21 (48.84)	91 (33.70)	3.697	0.055
E3	9 (20.93)	150 (55.56)	17.793	< 0.001