Multicenter case-control study of the risk factors for ulcerative colitis in China

Table 1 Social characteristics and household factors between ulcerative colitis and healthy controls

Variables	UC	Control	P value	OR	95%CI
Living area
Rural	16.4%	15.7%
Town	16.6%	12.9%	0.617	0.930	0.702-1.234
City	67.0%	71.4%	0.054	0.711	0.569-1.887
Education
Primary or below	14.3%	13.2%
Secondary	39.7%	36.8%	0.959	0.994	0.781-1.265
College or above	46.0%	50.0%	0.164	0.846	0.669-1.071
Feeling stress
None	21.5%	21.3%
Occasionally	55.6%	66.5%	0.056	0.828	0.682-1.005
Often	22.9%	12.2%	0.000	1.858	1.440-2.398
Water source
Boiled well or tap water water	82.0%	68.5%
Well water	3.4%	1.9%	0.118	1.494	0.903-2.471
Tap water	5.4%	21.6%	0.000	0.21	0.159-0.279
Mineral water	9.2%	8.0%	0.758	0.957	0.723-1.267
Lavatory
Closestool	11.3%	9.8%
Squat pan	39.4%	41.6%	0.173	0.829	0.634-1.085
Flush toilet	49.3%	48.6%	0.368	0.886	0.680-1.154
Refrigerator	78.7%	81.1%	0.181	0.86	0.690-1.073

UC: Ulcerative colitis; OR: Odds ratio.