Table 1 The characteristics of cases and controls
Variables | Controls [n(%)] | Cases [n(%)] | χ2 | P |
|---|---|---|---|---|
Sex | Â | Â | 0.000 | 1.000 |
 male | 433(67.0) | 433(67.0) |  |  |
 female | 213(33.0) | 213(33.0) |  |  |
Age | Â | Â | 3.802 | 0.149 |
  < 50 | 87(13.5) | 97(15.0) |  |  |
 50~60 | 233(36.1) | 258(39.9) |  |  |
  ≥ 60 | 326(50.5) | 291(45.0) |  |  |
Education Level |  |  | 101.492 | < 0.001 |
  ≤ Primary | 281(44.7) | 462(72.6) |  |  |
  ≥ Junior | 347(55.3) | 174(27.4) |  |  |
Household income (yuan) |  |  | 120.587 | < 0.001 |
  <  2000/month | 305(49.8) | 493(79.6) |  |  |
  ≥ 2000/month | 308(50.2) | 126(20.4) |  |  |
Ever smoking |  |  | 14.984 | < 0.001 |
 No | 300(47.5) | 236(36.8) |  |  |
 Yes | 332(52.5) | 406(63.2) |  |  |
Ever drinking |  |  | 18.166 | < 0.001 |
 No | 428(67.8) | 361(56.2) |  |  |
 Yes | 203(32.2) | 281(43.8) |  |  |
Hot food |  |  | 86.588 | < 0.001 |
 No | 367(58.0) | 205(32.0) |  |  |
 Yes | 266(42.0) | 435(68.0) |  |  |
Hard food |  |  | 39.041 | < 0.001 |
 No | 314(49.8) | 207(32.5) |  |  |
 Yes | 317(50.2) | 430(67.5) |  |  |
Pickled food |  |  | 39.799 | < 0.001 |
  < 5times/week | 333(52.6) | 224(35.1) |  |  |
  ≥ 5times/week | 300(47.4) | 415(64.9) |  |  |
Fried food | Â | Â | 0.607 | 0.436 |
  < 5times/week | 452(71.6) | 445(69,6) |  |  |
  ≥ 5times/week | 179(28.4) | 179(30.4) |  |  |
Fruits |  |  | 66.239 | < 0.001 |
  ≥ 5times/week | 399(63.1) | 259(40.3) |  |  |
  < 5times/week | 233(36.9) | 283(59.7) |  |  |