Table 1.
Characteristic in case and healthy control groups and the associated distribution of risk factors.
| Characteristic | Case group (n=500) | Control group (n=500) | P-value | |
|---|---|---|---|---|
| Gender | Male | 305 (61.0%) | 302 (60.4%) | |
| Female | 195 (39.0%) | 198 (39.6%) | 0.85 | |
| Age (years) | <30 | 2 (0.4%) | 5 (1.0%) | |
| 30-39 | 14 (2.8%) | 16 (3.2%) | ||
| 40-49 | 64 (12.8%) | 70 (14.0%) | ||
| 50-59 | 176 (35.2%) | 196 (39.2%) | ||
| 60-69 | 174 (34.8%) | 148 (19.7%) | ||
| ≥70 | 70 (14.0%) | 65 (13.0%) | 0.42 | |
| Education | Junior high school or lower | 318 (63.6%) | 130 (26.0%) | |
| High school | 97 (19.4%) | 144 (28.8%) | ||
| Greater than high school | 85 (17.0%) | 226 (45.2%) | 0.00 | |
| Smoking (pack-years) | 14.25 (0.0-36.0) | 0.00 (0.0-6.9) | 0.00 | |
| Fish and shrimps (g/day) | 4.00 (2.5-17.1) | 14.29 (3.3-28.6) | 0.00 | |
| Vegetable (g/day) | 177.10 (148.3-199.2) | 205.60 (174.8-407.9) | 0.00 | |
| Fruit (g/day) | 60.70 (31.40-101.90) | 99.50 (49.80-201.30) | 0.00 | |
| Meat | Deficient | 296 (59.2%) | 304 (60.8%) | |
| Normal | 108 (21.6%) | 128 (25.6%) | ||
| Over-sufficient | 96 (19.2%) | 68 (13.6%) | 0.04 | |
| Dairy products | Deficient | 499 (99.8%) | 457 (91.4%) | |
| Sufficient | 1 (0.2%) | 43 (8.6%) | 0.00 | |
| Soybean products and nuts | deficient | 327 (65.4%) | 228 (45.6%) | |
| Normal | 93 (18.6%) | 80 (16.0%) | ||
| Over-sufficient | 80 (16.0%) | 192 (38.4%) | 0.00 | |
| Alcohol (times/week) | 0 | 276 (55.2%) | 297 (59.4%) | |
| 1-2 | 104 (20.8%) | 130 (26.0%) | ||
| 3-6 | 31 (6.2%) | 43 (8.6%) | ||
| ≥7 | 89 (17.8%) | 30 (6.0%) | 0.00 | |
| Exposure to pesticide | Absent | 398 (79.6%) | 473 (94.6%) | |
| Present | 102 (20.4%) | 27 (5.4%) | 0.00 | |
| Exposure to gasoline/diesel | Absent | 487 (97.4%) | 496 (99.2%) | |
| Present | 13 (2.6%) | 4 (0.8%) | 0.04 | |
| Cooking emissions (total dish-years) | Absent | 244 (48.8%) | 250 (50.0%) | |
| ≤50 | 149 (29.8%) | 152 (30.4%) | ||
| 51-100 | 61 (12.2%) | 80 (16.0%) | ||
| 101-150 | 46 (9.2%) | 18 (3.6%) | 0.00 | |
| Pneumonia history | Absent | 477 (95.4%) | 490 (98.0%) | |
| Present | 23 (4.6%) | 10 (2.0%) | ||
| COPD history | Absent | 449 (89.8%) | 489 (97.8%) | |
| Present | 51 (10.2%) | 11 (2.2%) | 0.00 | |
| Pulmonary tuberculosis history | Absent | 470 (94.0%) | 486 (97.2%) | |
| Present | 30 (6.0%) | 14 (2.8%) | 0.02 | |
| Bronchial asthma history | Absent | 488 (97.6%) | 495 (99.0%) | |
| Present | 12 (2.4%) | 5 (1.0%) | 0.10 | |
| Cancer family history | Absent | 330 (66.0%) | 397 (79.4%) | |
| Present | 170 (34.0%) | 103 (20.6%) | 0.00 | |
| BMI (kg/m2) | <18.5 | 49 (9.8%) | 15 (3.0%) | |
| 18.5-24 | 302 (60.4%) | 230 (46.0%) | ||
| ≥24 | 149 (29.8%) | 255 (51.0%) | 0.00 | |
| Histology types | Squamous cell | 141(28.2%) | ||
| Adenocarcinomas | 176(35.2%) | |||
| Small cell | 126(25.2%) | |||
| Other carcinomas* | 57(11.4%) | |||