Table 2.
Demographic characteristics and main risk factors of stomach cancer and population controls stratified by proxy interviews
| Non-proxy, N (%) | Proxy, N (%) | Overall, N (%) | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Characteristics | Cases (n=1,327) | Controls (n=6,056) | p-value | Cases (n=573) | Controls (n=476) | p-value | Cases (n=1,900) | Controls (n=6,532) | p-value |
| County | |||||||||
| Dafeng | 498 (37.5) | 2387 (39.4) | <0.001 | 143 (25.0) | 121 (25.4) | <0.001 | 641 (33.7) | 2508 (38.4) | <0.001 |
| Ganyu | 328 (24.7) | 1755 (29.0) | 199 (34.7) | 117 (24.6) | 527 (27.7) | 1872 (28.7) | |||
| Chuzhou | 404 (30.4) | 1039 (17.2) | 50 (8.7) | 70 (14.7) | 454 (23.9) | 1109 (17.0) | |||
| Tongshan | 97 (7.3) | 875 (14.5) | 181 (31.6) | 168 (35.3) | 278 (14.6) | 1043 (16.0) | |||
| Gender | |||||||||
| Male | 1010 (76.1) | 4382 (72.4) | 0.005 | 391 (68.2) | 331 (69.5) | 0.65 | 1401 (73.7) | 4713 (72.2) | 0.17 |
| Female | 317 (23.9) | 1674 (27.6) | 182 (31.8) | 145 (30.5) | 499 (26.3) | 1819 (27.9) | |||
| Age | |||||||||
| <50 | 128 (9.7) | 648 (10.7) | 0.12 | 57 (10.0) | 51 (10.7) | 0.24 | 185 (9.7) | 699 (10.7) | 0.31 |
| 50–59 | 286 (21.6) | 1366 (22.6) | 121 (21.1) | 84 (17.7) | 407 (21.4) | 1450 (22.2) | |||
| 60–69 | 478 (36.0) | 1977 (32.7) | 174 (30.4) | 132 (27.7) | 652 (34.3) | 2109 (32.3) | |||
| ≥70 | 435 (32.8) | 2065 (34.1) | 221 (38.6) | 209 (43.9) | 656 (34.5) | 2274 (34.8) | |||
| Mean (SD) | 63.9 (10.5) | 63.8 (11.1) | 0.84 | 64.6 (11.5) | 66.2 (12.6) | 0.03 | 64.1 (10.8) | 64.0 (11.3) | 0.73 |
| Education | |||||||||
| Illiterate | 659 (49.8) | 2943 (48.7) | 0.001 | 295 (51.6) | 272 (57.1) | 0.005 | 954 (50.3) | 3215 (49.3) | <0.001 |
| Primary school | 460 (34.7) | 1902 (31.5) | 203 (35.5) | 125 (26.3) | 663 (35.0) | 2027 (31.1) | |||
| Middle school | 169 (12.8) | 941 (15.6) | 55 (9.6) | 66 (13.9) | 224 (11.8) | 1007 (15.5) | |||
| High school or above | 36 (2.7) | 257 (4.3) | 19 (3.3) | 13 (2.7) | 55 (2.9) | 270 (4.1) | |||
| Income 10 years ago (Yuan/year) | |||||||||
| <1000 | 315 (24.4) | 1265 (21.2) | 0.003 | 150 (27.0) | 128 (27.7) | 0.26 | 465 (25.2) | 1393 (21.7) | <0.001 |
| 1000–1499 | 261 (20.2) | 1124 (18.8) | 122 (22.0) | 94 (20.4) | 383 (20.8) | 1218 (18.9) | |||
| 1500–2499 | 351 (27.2) | 1604 (26.9) | 145 (26.1) | 103 (22.3) | 496 (26.9) | 1707 (26.5) | |||
| ≥2500 | 364 (28.2) | 1979 (33.1) | 138 (24.9) | 137 (29.7) | 502 (27.2) | 2116 (32.9) | |||
| Body mass index (kg/m2) | |||||||||
| <18.5 | 229 (17.3) | 374 (6.2) | <0.001 | 69 (12.1) | 36 (7.7) | <0.001 | 298 (15.8) | 410 (6.3) | <0.001 |
| 18.5-<24 | 898 (68.0) | 3681 (61.1) | 379 (66.5) | 289 (61.8) | 1277 (67.5) | 3970 (61.1) | |||
| 24-<28 | 157 (11.9) | 1617 (26.8) | 98 (17.2) | 126 (26.9) | 255 (13.5) | 1743 (26.8) | |||
| ≥28 | 37 (2.8) | 355 (5.9) | 24 (4.2) | 17 (3.6) | 61 (3.2) | 372 (5.7) | |||
| Daily energy intake (kcal/day): Mean (SD) | 2244.1 (847.0) | 2145.6 (808.2) | <0.001 | 2065.8 (794.8) | 1957.7 (798.4) | 0.03 | 2190.3 (835.4) | 2131.9 (808.9) | 0.007 |
| Tobacco smoking | |||||||||
| Never | 469 (35.3) | 2859 (47.2) | <0.001 | 265 (46.3) | 277 (58.2) | <0.001 | 734 (38.6) | 3136 (48.0) | <0.001 |
| Ever | 858 (64.7) | 3197 (52.8) | 308 (53.8) | 199 (41.8) | 1166 (61.4) | 3396 (52.0) | |||
| Pack-years of tobacco smoking | |||||||||
| Never | 469 (38.8) | 2859 (50.8) | <0.001 | 265 (50.7) | 277 (65.3) | <0.001 | 734 (42.4) | 3136 (51.8) | <0.001 |
| 1 to 19 | 155 (12.8) | 700 (12.4) | 64 (12.2) | 46 (10.9) | 219 (12.6) | 746 (12.3) | |||
| 20–39 | 223 (18.4) | 979 (17.4) | 80 (15.3) | 49 (11.6) | 303 (17.5) | 1028 (17.0) | |||
| ≥40 | 363 (30.0) | 1087 (19.3) | 114 (21.8) | 52 (12.3) | 477 (27.5) | 1139 (18.8) | |||
| Alcohol drinking | |||||||||
| Never | 610 (46.0) | 2941 (48.6) | 0.09 | 293 (51.1) | 282 (59.2) | 0.009 | 903 (47.5) | 3223 (49.3) | 0.16 |
| Ever | 717 (54.0) | 3115 (51.4) | 280 (48.9) | 194 (40.8) | 997 (52.5) | 3309 (50.7) | |||
| Family history of stomach cancer | |||||||||
| No | 1179 (88.9) | 5708 (94.3) | <0.001 | 532 (92.8) | 462 (97.1) | 0.002 | 1711 (90.1) | 6170 (94.5) | <0.001 |
| Yes | 148 (11.2) | 348 (5.8) | 41 (7.2) | 14 (2.9) | 189 (10.0) | 362 (5.5) | |||
| Exercise ten years ago | |||||||||
| No | 950 (71.6) | 4298 (71.0) | 0.65 | 354 (61.8) | 266 (55.9) | 0.05 | 1304 (68.6) | 4564 (69.9) | 0.3 |
| Yes | 377 (28.4) | 1758 (29.0) | 219 (38.2) | 210 (44.1) | 596 (31.4) | 1968 (30.1) | |||
| H. pylori infection | |||||||||
| No | 239 (23.5) | 1499 (29.7) | <0.001 | 93 (24.7) | 114 (30.1) | 0.1 | 332 (23.8) | 1613 (29.7) | <0.001 |
| Yes | 779 (76.5) | 3546 (70.3) | 283 (75.3) | 265 (69.9) | 1062 (76.2) | 3811 (70.3) | |||
Based on the chi-square test for category variables and t-test for continuous variables.