Table 2.

The distribution of major factors and their associations with lung cancer risk

VariablesCase (%; N = 1,424)Control (%; N = 4,543)Crude OR (95% CI)Adjusted OR (95% CI)a
Ever smoking
 No394 (27.7)1,860 (40.9)1.001.00
 Yes1,030 (72.3)2,683 (59.1)1.81 (1.59–2.07)2.54 (2.17–2.99)
Pack-years of smoking
 Never smoker394 (27.7)1,860 (40.9)1.001.00
 <30 y262 (18.4)1,088 (23.9)1.14 (0.96–1.35)1.60 (1.32–1.94)
 ≥30 y768 (53.9)1,595 (35.1)2.27 (1.98–2.61)3.68 (3.08–4.40)
Ptrend<0.001<0.001
Alcohol drinking status
 Never or seldom837(58.8)2,782 (61.2)1.001.00
 Often587(41.2)1,761 (38.8)1.11 (0.98–1.25)1.04 (0.90–1.19)
Factory nearby
 No1 216 (86.7)4,021 (89.9)1.001.00
 Yes186 (13.3)450 (10.1)1.37 (1.14–1.64)1.55 (1.28–1.89)
High-temperature cooking oil
 No911 (64.0)3,194 (70.3)1.001.00
 Yes513 (36.0)1,349 (29.7)1.33 (1.18–1.51)1.26 (1.10–1.43)
Consumption of fried food
 No651 (45.7)2,539 (55.9)1.001.00
 Yes773 (54.3)2,004 (44.1)1.50 (1.34–1.70)1.32 (1.15–1.52)
Poor ventilation in kitchen
 No558 (39.2)1,944 (42.8)1.001.00
 Yes866 (60.8)2,599 (57.2)1.16 (1.03–1.31)1.12 (0.98–1.28)
Family history of lung cancer
 No1,356 (95.2)4,433 (97.6)1.001.00
 Yes68 (4.8)110 (2.4)2.02 (1.49–2.75)1.98 (1.42–2.74)
Green tea drinking
 No952 (71.2)3,028 (71.9)1.001.00
 Yes386 (28.8)1,186 (28.1)1.04 (0.90–1.19)0.85 (0.73–1.00)
Exercise ten years ago
 No1,111 (78.0)3,543 (78.0)1.001.00
 Yes313 (22.0)1,000 (22.0)1.00 (0.87–1.15)0.82 (0.70–0.96)
  • aAdjusted on age (continuous), gender (male = 1, female = 0), education level (illiteracy = 1, primary = 2, middle = 3, high = 4, college = 5), income (Yuan/year) 10 years ago (continuous), BMI (continuous), family history of lung cancer (yes = 1, no = 0), pack-year of smoking (continuous, except for variable of ever smoking), ethanol consumption (mL/week, continuous, except for variable of alcohol drinking status), and study area (Dafeng = 1, Ganyu = 2).