Table 1. Demographic and selected risk factors of colorectal cancer cases and controls in Chinese population.
| Cases | Controls | P-value | Community- | Hospital- | P-value | |
|---|---|---|---|---|---|---|
| (n = 890) | (n = 890) | between | Derived | Derived | Between | |
| cases | controls | controls | control | |||
| and controls | (n = 366) | (n = 524) | groups | |||
| Age, yr, (mean±SD) | 56.6 ± 10.3 | 56.5 ± 10.0 | 0.83 | 63.3 ± 6.2 | 51.8 ± 9.4 | <0.01 |
| Sex (n, %) | 1 | <0.01 | ||||
| Men | 495 (55.6) | 495 (55.6) | 262 (71.6) | 233 (44.5) | ||
| Women | 395 (44.4) | 395 (44.4) | 104 (28.4) | 291 (55.5) | ||
| Marital status (n, %) | 0.29 | 0.15 | ||||
| Married | 849 (95.4) | 839 (94.3) | 340 (92.9) | 499 (95.2) | ||
| Unmarried/divorces/widowed | 41 (4.6) | 51 (5.7) | 26 (7.1) | 25 (4.8) | ||
| Residence (n, %) | 1 | 0.06 | ||||
| Urban | 602 (67.6) | 602 (67.6) | 261 (71.3) | 341 (65.1) | ||
| Rural | 288 (32.4) | 288 (32.4) | 105 (28.7) | 183 (34.9) | ||
| Educational Level (n, %) | <0.01 | <0.01 | ||||
| Primary school or blow | 279 (31.3) | 207 (23.3) | 63 (17.2) | 144 (27.5) | ||
| Secondary school | 229 (25.7) | 238 (26.7) | 76 (20.8) | 162 (30.9) | ||
| High school | 221 (24.8) | 243 (27.3) | 123 (33.6) | 120 (22.9) | ||
| College or Above | 161 (18.1) | 202 (22.7) | 104 (28.4) | 98 (18.7) | ||
| Occupation (n, %) | 0.11 | <0.01 | ||||
| Administrator/other white collar worker | 119 (13.4) | 137 (15.4) | 20 (5.5) | 117 (22.4) | ||
| Blue collar worker | 179 (20.1 | 203 (22.8) | 53 (14.5) | 150 (28.7) | ||
| Farmer/other | 592 (66.5) | 549 (61.8) | 293 (80.1) | 256 (48.9) | ||
| Income (Yuan/month) (n, %) | <0.01 | <0.01 | ||||
| <2,000 | 135 (15.2) | 139 (15.7) | 38 (10.4) | 101 (19.3) | ||
| 2,001–5,000 | 282 (31.7) | 309 (34.8) | 164 (45.1) | 145 (27.7) | ||
| 5,001–8,000 | 238 (26.7) | 287 (32.3) | 129 (35.4) | 158 (30.2) | ||
| >8,001 | 235 (26.4) | 150 (16.9) | 30 (8.2) | 120 (22.9) | ||
| BMI (mean±SD) | 22.9 ± 3.5 | 23.2 ± 3.1 | 0.05 | 23.7 ± 3.0 | 22.9 ± 3.1 | 0.21 |
| Regular smoker (n, %) | 238 (26.7) | 272 (30.6) | 0.08 | 126 (34.4) | 146 (27.9) | 0.04 |
| Passive smoking (n, %) | 548 (61.6) | 414 (46.6) | <0.01 | 72 (19.7) | 342 (65.3) | <0.01 |
| Regular drinker (n, %) | 145 (16.3) | 128 (14.4) | 0.29 | 50 (13.7) | 78 (14.9) | 0.63 |
| Family history of cancer (n, %) | 133 (14.9) | 80 (9.0) | <0.01 | 31 (8.5) | 49 (9.4) | 0.72 |
| Physical activity (n, %) | <0.01 | <0.01 | ||||
| Less active | 473 (53.1) | 458 (51.6) | 145 (39.8) | 313 (59.7) | ||
| Moderate active | 296 (33.3) | 223 (25.1) | 133 (36.5) | 90 (17.2) | ||
| More active | 121 (13.6) | 207 (23.3) | 86 (23.6) | 121 (23.1) | ||
| Menopausal status (n, %) a | 0.35 | <0.01 | ||||
| Premenopausal | 114 (28.9) | 127 (32.2) | 4 (3.8) | 123 (42.3) | ||
| Postmenopausal | 281 (71.1) | 268 (67.8) | 100 (96.2) | 168 (57.7) |
a Among women subgroup.