Table 1.

Basic Characteristic of Lung Cancer Patents and Healthy Controls

Variables	Cases	Controls	Unmatched	Matched
	N = 190	N = 380	OR (95% CI)a	OR (95% CI)b
Gender
Male	115 (60.5%)	230 (60.5%)	1.00 (0.70-1.43)	1.00 (0.70-1.43)
Female	75 (39.5%)	150 (39.5%)	1	1
Age (years, mean ± SD)	65.5 ± 11.9	64.4 ± 11.8
Smoking status
Current and ever smokers	102 (53.7%)	118 (31.1%)	2.57 (1.80-3.68)c	4.67 (2.75-7.93)c
Never smokers	88 (46.3%)	262 (68.9%)	1	1
Pack-years of smoking
≥40	65 (34.2%)	60 (15.8%)	3.23 (2.11-4.94)c	5.76 (3.22-10.32)c
1-39	37 (19.5%)	58 (15.3%)	1.90 (1.18-3.06)d	3.41 (1.81-6.41)c
0	88 (46.3%)	262 (68.9%)	1	1
Green tea consumption (cups/day)
0	146 (76.8%)	250 (65.8%)	2.96 (1.64-5.34)c	3.02 (1.64-5.55)c
< 1	29 (15.3%)	54 (14.2%)	2.72 (1.33-5.56)d	2.49 (1.21-5.12)e
≥ 1	15 (7.9%)	76 (20.0%)	1	1
Green tea consumption (years)
0	146 (76.8%)	250 (65.8%)	1.75 (1.03-2.99)e	1.92 (1.09-3.36)e
≤10	23 (12.1%)	67 (17.6%)	1.03 (0.52-2.04)	1.02 (0.51-2.01)
>10	21 (11.1%)	63 (16.6%)	1	1
Vegetables and fruits intake (servings/week)
≤14	48 (25.3%)	110 (28.9%)	0.94 (0.62-1.43)	0.89 (0.59-1.37)
15-20	51 (26.8%)	74 (19.5%)	1.48 (0.96, 2.29)	1.41 (0.91-2.18)
≥21	91 (47.9%)	196 (51.6%)	1	1
Exposure to cooking fumes (hours/week)
≥3	17 (8.9%)	16 (4.2%)	2.41 (1.19-4.89)e	2.77 (1.29-5.96)d
1-3	19 (10.0%)	15 (4.0%)	2.87 (1.42-5.80)d	3.38 (1.57-7.29)d
<1	154 (81.1%)	349 (91.8%)	1	1
Family history of lung cancer
Yes	15 (7.9%)	6 (1.6%)	5.34 (2.04-14.00)d	6.80 (2.24-20.65)d
No	175 (92.1%)	374 (98.4%)	1	1

^aData were calculated by unconditional logistic regression;

^bData were matched by age and gender, calculated by conditional logistic regression;

^cP<0.001;

^d0.001<P<0.01;

^e0.01<P<0.05.