Table 2 Individual demographic characteristics by region
| Â | Total | Beijing (North) | Liaoning (Northeast) | Hunan (Central) | Guangdong (South) | Zhejiang (East) | Shannxi (Northwest) | Sichuan (Southwest) | Statistical value | P-value |
|---|---|---|---|---|---|---|---|---|---|---|
Demographic Characteristic | Total N = 4211 | Total N = 641 | Total N = 832 | Total N = 546 | Total N = 604 | Total N = 606 | Total N = 483 | Total N = 499 | Â | Â |
| Â | N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | Â | Â |
Age at diagnosis (years) | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â |
   Mean ± SD | 48.68 ± 10.47 | 50.45 ± 10.92 | 48.88 ± 9.95 | 48.25 ± 10.34 | 47.82 ± 10.94 | 47.35 ± 9.58 | 50.10 ± 11.01 | 47.86 ± 10.32 | 7.63* | < 0.001 |
   ≤ 40 | 919 (21.8) | 113 (17.6) | 161 (19.4) | 133 (24.4) | 155 (25.7) | 147 (24.3) | 89 (18.4) | 121 (24.2) |  |  |
   40-69 | 3126 (74.2) | 489 (76.3) | 645 (77.5) | 387 (70.9) | 429 (71.0) | 443 (73.1) | 369 (76.4) | 364 (72.9) |  |  |
   ≥ 70 | 166 (3.9) | 39 (6.1) | 26 (3.1) | 26 (4.8) | 20 (3.3) | 16 (2.6) | 25 (5.2) | 14 (2.8) |  |  |
Body Mass Index (kg/m 2 ) (1) | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â |
   Mean ± SD | 23.35 ± 2.89 | 24.65 ± 3.46 | 24.01 ± 3.08 | 21.72 ± 1.85 | 23.25 ± 3.47 | 22.28 ± 2.86 | 23.25 ± 1.29 | 23.25 ± 1.82 | 67.42* | < 0.001 |
   ≤ 24.99 | 3287 (78.1) | 371 (57.9) | 559 (67.2) | 520 (95.2) | 422 (70.2) | 492 (81.2) | 464 (96.1) | 460 (92.2) |  |  |
   ≥ 25.00 | 921 (21.9) | 270 (42.1) | 273 (32.8) | 26 (4.8) | 180 (29.8) | 114 (18.8) | 19 (3.9) | 39 (7.8) |  |  |
Occupation | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â |
   Homemaker | 173 (4.0) | 17 (2.7) | 2 (0.2) | 72 (13.2) | 39 (6.5) | 11 (1.8) | 14 (2.9) | 18 (3.6) | 6.52** | < 0.001 |
   Manual worker | 1893 (45.0) | 230 (35.9) | 258 (31.1) | 185 (33.9) | 159 (26.3) | 487 (80.4) | 261 (54.0) | 313 (62.7) |  |  |
   White-collar worker | 1028 (24.4) | 203 (31.7) | 174 (20.9) | 168 (30.8) | 167 (27.6) | 61 (10.1) | 153 (31.7) | 102 (20.4) |  |  |
   Other | 529 (12.6) | 70 (10.9) | 99 (11.9) | 114 (20.9) | 162 (26.8) | 40 (6.6) | 19 (3.9) | 25 (5.0) |  |  |
   Unknown | 588 (14.0) | 121 (18.9) | 299 (35.9) | 7 (1.2) | 77 (12.8) | 7 (1.1) | 36 (7.5) | 41 (8.2) |  |  |
Education | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â |
   None | 186 (4.4) | 5 (0.8) | 1 (0.1) | 0 (0.0) | 41 (6.8) | 124 (20.5) | 14 (2.9) | 1 (0.2) | 4.63*** | < 0.001 |
   Primary school | 462 (11.0) | 3 (0.5) | 0 (0.0) | 125 (22.9) | 116 (19.2) | 173 (28.5) | 39 (8.1) | 6 (1.2) |  |  |
   Middle school | 606 (14.4) | 0 (0.00) | 0 (0.0) | 147 (26.9) | 172 (28.5) | 165 (27.2) | 115 (23.8) | 7 (1.4) |  |  |
   High school | 441 (10.5) | 0 (0.00) | 2 (0.2) | 122 (22.3) | 143 (23.7) | 56 (9.2) | 116 (24.0) | 2 (0.4) |  |  |
   University and above | 396 (9.4) | 4 (0.6) | 23 (2.8) | 150 (27.5) | 112 (18.5) | 29 (4.8) | 76 (15.7) | 2 (0.4) |  |  |
   Unknown | 2120 (50.3) | 629 (98.1) | 806 (96.9) | 2 (0.4) | 20 (3.3) | 59 (9.8) | 123 (25.5) | 481 (96.4) |  |  |
Marital Status | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â |
   Single | 51 (1.2) | 6 (0.9) | 9 (1.1) | 4 (0.7) | 17 (2.8) | 5 (0.8) | 3 (0.6) | 7 (1.4) | 56.43** | < 0.001 |
   Married | 4090 (97.1) | 620 (96.7) | 821 (98.7) | 525 (96.2) | 586 (97.0) | 589 (97.2) | 474 (98.1) | 475 (95.2) |  |  |
   Widowed/Divorced | 52 (1.2) | 12 (1.9) | 0 (0.0) | 17 (3.1) | 0 (0.0) | 7 (1.2) | 5 (1.0) | 11 (2.2) |  |  |
   Unknown | 18 (0.5) | 3 (0.5) | 2 (0.2) | - | 1 (0.2) | 5 (0.8) | 1 (0.2) | 6 (1.2) |  |  |