Table 1 Subject characteristics by case and control groups
Variables | Cases N (%) (N = 449) | Controls N (%) (N = 512) | χ2 | P |
|---|---|---|---|---|
Age (years) | 0.194 | 0.979 | ||
 < 45 | 39 (8.7) | 43 (8.4) |  |  |
 45 ~ | 197 (43.9) | 229 (44.7) |  |  |
 60 ~ | 192 (42.7) | 214 (41.8) |  |  |
 ≥ 75 | 21 (4.7) | 26 (5.1) |  |  |
Sex | 3.290 | 0.070 | ||
 Male | 293 (65.3) | 305 (59.6) |  |  |
 Female | 156 (34.7) | 207 (40.4) |  |  |
Ethnicity | 0.274 | 0.601 | ||
 Han | 443 (98.7) | 507 (99.0) |  |  |
 Others | 6 (1.3) | 5 (1.0) |  |  |
Education | 90.131 | < 0.001 | ||
 Primary school or less | 231 (51.4) | 145 (28.3) |  |  |
 High school | 174 (38.8) | 199 (38.9) |  |  |
 College or higher | 44 (9.8) | 168 (32.8) |  |  |
Marital status | 0.204 | 0.651 | ||
 Married | 429 (95.5) | 486 (94.9) |  |  |
 Unmarried or others | 20 (4.5) | 26 (5.1) |  |  |
Occupation | 75.731 | < 0.001 | ||
 Agriculture, forestry, animal husbandry and fishery personnel | 138 (30.7) | 80 (15.6) |  |  |
 Production transport workers | 109 (24.3) | 89 (17.4) |  |  |
 Enterprises and institutions personnel | 123 (27.4) | 260 (50.8) |  |  |
 Business service personnel | 33 (7.4) | 58 (11.3) |  |  |
 Unemployed or others | 46 (10.2) | 25 (4.9) |  |  |
BMI (kg/m2) | 11.815 | 0.003 | ||
 < 18.5 | 32 (7.1) | 20 (3.9) |  |  |
 18.5 ~ | 278 (61.9) | 286 (55.9) |  |  |
 ≥ 24.0 | 139 (31.0) | 206 (40.2) |  |  |
Smoking | 68.114 | < 0.001 | ||
 No | 188 (41.9) | 350 (68.4) |  |  |
 Yes | 261 (58.1) | 162 (31.6) |  |  |
Passive smoking | 48.699 | < 0.001 | ||
 No | 131 (29.2) | 263 (51.4) |  |  |
 Yes | 318 (70.8) | 249 (48.6) |  |  |
Alcohol consumption | 13.787 | < 0.001 | ||
 No | 308 (68.6) | 405 (79.1) |  |  |
 Yes | 141 (31.4) | 107 (20.9) |  |  |
Tea drinking | 1.255 | 0.263 | ||
 No | 239 (53.2) | 254 (49.6) |  |  |
 Yes | 210 (46.8) | 258 (50.4) |  |  |
History of lung diseases | 18.235 | < 0.001 | ||
 No | 381 (84.9) | 478 (93.4) |  |  |
 Yes | 68 (15.1) | 34 (6.6) |  |  |
History of other diseases | 5.326 | 0.021 | ||
 No | 264 (58.8) | 338 (66.0) |  |  |
 Yes | 185 (41.2) | 174 (34.0) |  |  |
Family history of cancer | 5.070 | 0.024 | ||
 No | 336 (74.8) | 414 (80.9) |  |  |
 Yes | 113 (25.2) | 98 (19.1) |  |  |
Occupational physical activity | 52.066 | < 0.001 | ||
 Light | 144 (32.1) | 278 (54.3) |  |  |
 Median | 169 (37.6) | 150 (29.3) |  |  |
 Heavy | 136 (30.3) | 84 (16.4) |  |  |
Physical exercise | 62.254 | < 0.001 | ||
 Not often | 316 (70.4) | 231 (45.1) |  |  |
 Usually | 133 (29.6) | 281 (54.9) |  |  |
Cooking oil fumes | 31.925 | < 0.001 | ||
 No | 84 (18.7) | 167 (32.6) |  |  |
 Few | 231 (51.4) | 241 (47.1) |  |  |
 Some | 106 (23.6) | 93 (18.2) |  |  |
 Heavy | 28 (6.2) | 11 (2.1) |  |  |
Decoration within ten years | 0.646 | 0.421 | ||
 No | 278 (61.9) | 304 (59.4) |  |  |
 Yes | 171 (38.1) | 208 (40.6) |  |  |
Pollution near the residence | 27.114 | < 0.001 | ||
 No | 368 (82.0) | 476 (93.0) |  |  |
 Yes | 81 (18.0) | 36 (7.0) |  |  |
Ventilation status | 4.272 | 0.118 | ||
 Bad | 11 (2.4) | 8 (1.6) |  |  |
 General | 48 (10.7) | 38 (7.4) |  |  |
 Well | 390 (86.9) | 466 (91.0) |  |  |
Pathological types | – | – | ||
 Adenocarcinoma | 277 (61.7) | – |  |  |
 Squamous cell carcinoma | 96 (21.4) | – |  |  |
 Adenosquamous carcinoma | 7 (1.6) | – |  |  |
 Large cell carcinoma | 2 (0.4) | – |  |  |
 Small cell carcinoma | 38 (8.5) | – |  |  |
 Others | 29 (6.4) | – |  |  |