Characteristic | Invited to screening group | Control group (n=299 483) | ||
Screened (n=113 340) | Not screened (n=224 677) | Total (n=338 017) | ||
Sex (%) | ||||
Men | 51 080 (45.07) | 115 879 (51.58) | 166 959 (49.39) | 148 182 (49.48) |
Women | 62 260 (54.93) | 108 798 (48.42) | 171 058 (50.61) | 151 301 (50.52) |
Age at entry (%) | ||||
40–49 year | 45 636 (40.26) | 103 947 (46.27) | 149 583 (44.25) | 135 364 (45.20) |
50–59 year | 43 756 (38.61) | 75 252 (33.49) | 119 008 (35.21) | 112 468 (37.55) |
60–69 year | 23 948 (21.13) | 45 478 (20.24) | 69 426 (20.54) | 51 651 (17.25) |
Area (%) | ||||
Cixian | 22 135 (19.53) | 49 788 (22.16) | 71 923 (21.28) | 19 384 (6.47) |
Feicheng | 23 470 (20.71) | 18 718 (8.33) | 42 188 (12.48) | 58 106 (19.40) |
Linzhou | 19 805 (17.47) | 38 333 (17.06) | 58 138 (17.2) | 35 757 (11.94) |
Yancheng | 12 460 (10.99) | 41 081 (18.28) | 53 541 (15.84) | 66 525 (22.21) |
Yanting | 22 702 (20.03) | 43 500 (19.36) | 66 202 (19.59) | 33 325 (11.13) |
Yangzhong | 12 768 (11.27) | 33 257 (14.80) | 46 025 (13.62) | 86 386 (28.85) |
Person-years of follow-up* | 657 349 | 1 394 626 | 2 051 975 | 2 915 581 |
*Person-years are follow-up from cohort entry date to the date of last follow-up based on the analyses for upper gastrointestinal cancer incidence.