Table 2.
The demographic factors of colorectal cancer cases and controls.
| Characteristics | Case (n = 2799) | Control (n = 2799) | p a |
|---|---|---|---|
| Age (years), mean ± SD | 57.10 ±10.27 | 57.05 ± 9.89 | 0.858 |
| Energy(kcal/d), median (P25, P75) | 1481.09 (1197.73, 1815.78) |
1543.13 (1259.02, 1943.86) |
<0.001 |
| Men, n (%) | 1603 (57.27) | 1603 (57.27) | 1.000 |
| Maried, n (%) | 2661 (95.07) | 2554 (91.25) | <0.001 |
| Rural, n (%) | 997 (35.62) | 630 (22.51) | <0.001 |
| Educational level, n (%) | <0.001 | ||
| Primary school or below | 871 (31.12) | 619 (22.12) | |
| Middle school | 784 (28.01) | 713 (25.47) | |
| High school/technical school | 681 (24.33) | 751 (26.83) | |
| College or above | 463 (16.54) | 716 (25.58) | |
| Occupation, n (%) | 0.013 | ||
| Administrator | 395 (14.11) | 475 (16.97) | |
| Blue collar worker | 624 (22.29) | 608 (21.72) | |
| Farmer/other | 1780 (63.59) | 1716 (61.31) | |
| Income, n (%) | <0.001 | ||
| <2000 | 379 (13.54) | 358 (12.79) | |
| 2001–5000 | 935 (33.40) | 1085 (38.76) | |
| 5001–8000 | 830 (29.65) | 840 (30.01) | |
| ≥8001 | 655 (23.41) | 516 (18.44) | |
| Occupational activity, n (%) | <0.001 | ||
| Non-working | 334 (11.93) | 968 (34.58) | |
| Sedentary | 798 (28.51) | 587(20.97) | |
| Light occupational | 773 (27.62) | 653 (23.33) | |
| Moderate occupational | 417 (14.90) | 263 (9.40) | |
| Heavy activity | 477 (17.04) | 328 (11.72) | |
| MET(h/week), median (P25, P75) | 27.75 (8.50, 52.50) | 34.50 (16.00, 56.13) | <0.001 |
| Ever smoker, n (%) | 1103 (39.41) | 859 (30.69) | <0.001 |
| Passive smoker, n (%) | 793 (28.33) | 802 (28.65) | 0.790 |
| Regular drinker, n (%) | 504 (18.01) | 400 (14.29) | <0.001 |
| BMI (kg/m2), mean ± SD | 23.34 ± 3.28 | 23.56 ± 3.13 | 0.008 |
| Menopausal status, a n (%) | 0.229 | ||
| Premenopausal | 331 (27.68) | 305 (25.50) | |
| Postmenopausal | 865 (72.32) | 891 (74.50) | |
| First-degree relative with cancer, n (%) | 416 (14.86) | 238 (8.50) | <0.001 |
| Age at menarche, a mean ± SD | 14.95 ± 2.12 | 14.60 ± 3.07 | 0.713 |
Abbreviations: BMI, body mass index; MET, metabolic equivalent task; Continuous variables were assessed by the t test or Wilcoxon rank-sum test, and the chi-square test was used for the comparison of categorical variables. a Only for women.