Risk factors for sporadic colorectal cancer in southern Chinese

Table 2 Comparison of epidemiological factors for colorectal cancer

Variables	Adjusted OR (95% CI)1
	Test group	Validation group	Merged group
Smoking status
Non	1.00 (ref.)	1.00 (ref.)	1.00 (ref.)
Former	0.97 (0.52-1.80)	0.66 (0.30-1.46)	0.78 (0.49-1.23)
Current	1.41 (0.82-2.43)	0.79 (0.45-1.38)	1.01 (0.69-1.48)
Trend test P value	< 0.00001	0.187	< 0.00001
Drinking status
Non	1.00 (ref.)	1.00 (ref.)	1.00 (ref.)
Former	2.02 (0.93-4.41)	2.84 (1.03-7.81)	2.30 (1.27-4.17)
Current	14.69 (9.41-22.94)	3.82 (2.23-6.56)	8.61 (6.15-12.05)
Trend test P value	< 0.00001	0.023	< 0.00001
Family history of cancer
Negative	1.00 (ref.)	1.00 (ref.)	1.00 (ref.)
Positive	1.43 (0.94-2.18)	3.21 (1.31-7.84)	1.62 (1.12-3.34)
BMI (kg/m2)
≤ 23.9	1.00 (ref.)	1.00 (ref.)	1.00 (ref.)
≥ 24.0	1.34 (1.00-1.78)	1.60 (1.05-2.44)	1.39 (1.10-1.75)

¹Adjusted for age, sex, smoking status, alcohol drinking, family history of cancer, BMI.