Baseline characteristics of participants in the different groups*
| Characteristics | Group A (n=44 345) | Group B (n=43 930) | Group C (n=77 997) |
|---|---|---|---|
| Age, years | 42.77±7.86 | 42.87±7.87 | 42.79±8.21 |
| Sex | |||
| Men | 21 107 (47.6) | 20 790 (47.3) | 34 588 (44.3) |
| Women | 23 238 (52.4) | 23 140 (52.7) | 43 409 (55.7) |
| Education | |||
| Primary school | 15 469 (34.9) | 16 679 (38.0) | 24 232 (37.0) |
| Middle school | 27 134 (61.2) | 26 274 (59.8) | 46 209 (59.2) |
| College | 1738 (3.9) | 967 (2.2) | 2908 (3.7) |
| Missing | 4 (0.0) | 10 (0.0) | 16 (0.0) |
| Marriage | |||
| Married | 43 806 (98.8) | 43 441 (98.9) | 76 715 (98.4) |
| Unmarried | 366 (0.8) | 315 (0.7) | 931 (1.1) |
| Widow | 169 (0.4) | 164 (0.4) | 335 (0.4) |
| Missing | 4 (0.0) | 10 (0.0) | 16 (0.0) |
| Occupation | |||
| Farmer | 34 829 (78.5) | 34 694 (79.0) | 60 931 (78.1) |
| Worker | 8218 (18.5) | 8808 (20.1) | 14 941 (19.2) |
| Other | 1294 (2.9) | 418 (1.0) | 2109 (2.7) |
| Missing | 4 (0.0) | 10 (0.0) | 16 (0.0) |
| Income (RMB) | 10 699±6843 | 10 461±6983 | 10 638±6892 |
| Family history of cancer | |||
| Yes | 4979 (11.2) | 4616 (10.5) | 8249 (10.6) |
| No | 39 362 (88.8) | 39 304 (89.5) | 69 732 (89.4) |
| Missing | 4 (0.0) | 10 (0.0) | 16 (0.0) |
| History of stomach disease | |||
| Yes | 3545 (8.0) | 3423 (7.8) | 8169 (10.5) |
| No | 40 796 (92.0) | 40 497 (92.2) | 69 812 (89.5) |
| Missing | 4 (0.0) | 10 (0.0) | 16 (0.0) |
| Smoking | |||
| Men | |||
| Yes | 7158 (33.9) | 6886 (33.1) | 11 452 (33.1) |
| No | 13 946 (66.1) | 13 896 (66.8) | 23 128 (66.9) |
| Missing | 3 (0.0) | 8 (0.0) | 8 (0.0) |
| Women | |||
| Yes | 14 (0.1) | 18 (0.1) | 42 (0.1) |
| No | 23 223 (99.9) | 23 120 (99.9) | 43 359 (99.9) |
| Missing | 1 (0.0) | 2 (0.0) | 8 (0.0) |
| Total | |||
| Yes | 7172 (16.2) | 6904 (15.7) | 11 494 (14.7) |
| No | 37 169 (83.8) | 37 016 (84.3) | 66 487 (85.2) |
| Missing | 4 (0.0) | 10 (0.0) | 16 (0.0) |
| Drinking | |||
| Men | |||
| Yes | 8789 (41.6) | 8400 (40.4) | 13 890 (40.2) |
| No | 12 315 (58.3) | 12 382 (59.6) | 20 690 (59.8) |
| Missing | 3 (0.0) | 8 (0.0) | 8 (0.0) |
| Women | |||
| Yes | 196 (0.8) | 182 (0.8) | 326 (0.8) |
| No | 23 041 (99.2) | 22 956 (99.2) | 43 075 (99.2) |
| Missing | 1 (0.0) | 2 (0.0) | 8 (0.0) |
| Total | |||
| Yes | 8985 (20.3) | 8582 (19.5) | 14 216 (18.2) |
| No | 35 356 (79.7) | 35 338 (80.4) | 63 765 (81.8) |
| Missing | 4 (0.0) | 10 (0.0) | 16 (0.0) |
| BMI (kg/m2) | |||
| Low weight (<18.5) | 97 (0.2) | 116 (0.3) | 233 (0.3) |
| Normal weight (18.5–24.9) | 29 251 (66.0) | 28 732 (65.4) | 52 219 (67.0) |
| Overweight (25–29.9) | 13 969 (31.5) | 14 027 (31.9) | 23 793 (30.5) |
| Obese (≥30) | 1023 (2.3) | 1051 (2.4) | 1744 (2.2) |
| Missing | 5 (0.0) | 4 (0.0) | 8 (0.0) |
*Date are presented as means±SD or n (%).
BMI, body mass index; RMB, ren min bi.