Table 1. Pooled Characteristics of Enrolled Individuals and CRC Incidence and Mortality From 4 Sigmoidoscopy Screening Trials.
| Characteristic | Total participants, No. (%) | Usual care, participants, No. (%) | Screening, participants, No. (%) | ||
|---|---|---|---|---|---|
| Nonattenders | Attenders | ||||
| Colonoscopya | No colonoscopya | ||||
| No. of individuals | |||||
| Women | 181 971 | 112 245 | 19 058 | 6138 | 44 530 |
| Men | 176 233 | 108 466 | 15 893 | 9796 | 42 078 |
| Person-years, CRC incidence | |||||
| Women | 2 795 577 | 1 724 973 | 283 778 | 91 330 | 695 497 |
| Men | 2 590 547 | 1 589 544 | 218 599 | 142 282 | 640 122 |
| CRC incidenceb | |||||
| All | 8508 (2.4) | 5823 (2.6) | 935 (2.7) | 562 (3.5) | 1188 (1.4) |
| Distal | 4912 (1.4) | 3526 (1.6) | 577 (1.7) | 384 (2.4) | 425 (0.5) |
| Proximal | 3523 (1.0) | 2251 (1.0) | 348 (1.0) | 171 (1.1) | 753 (0.9) |
| Women | |||||
| All | 3544 (1.9) | 2368 (2.1) | 411 (2.2) | 180 (2.9) | 585 (1.3) |
| Distal | 1789 (1.0) | 1260 (1.1) | 225 (1.2) | 120 (2.0) | 184 (0.4) |
| Proximal | 1729 (1.0) | 1092 (1.0) | 180 (0.9) | 60 (1.0) | 397 (0.9) |
| Men | |||||
| All | 4964 (2.8) | 3455 (3.2) | 524 (3.3) | 382 (3.9) | 603 (1.4) |
| Distal | 3123 (1.8) | 2266 (2.1) | 352 (2.2) | 264 (2.7) | 241 (0.6) |
| Proximal | 1794 (1.0) | 1159 (1.1) | 168 (1.1) | 111 (1.1) | 356 (0.8) |
| Person-years, CRC mortality | |||||
| Women | 2 947 166 | 1 803 074 | 303 858 | 101 242 | 738 991 |
| Men | 2 736 393 | 1 666 686 | 233 322 | 157 974 | 678 411 |
| CRC mortalityb | |||||
| All | 2591 (0.7) | 1784 (0.8) | 328 (0.9) | 113 (0.7) | 366 (0.4) |
| Distal | 1353 (0.4) | 987 (0.4) | 205 (0.6) | 64 (0.4) | 97 (0.1) |
| Proximal | 1089 (0.3) | 703 (0.3) | 102 (0.3) | 45 (0.3) | 239 (0.3) |
| Women | |||||
| All | 1034 (0.6) | 689 (0.6) | 137 (0.7) | 41 (0.7) | 167 (0.4) |
| Distal | 447 (0.2) | 310 (0.3) | 77 (0.4) | 20 (0.3) | 40 (0.1) |
| Proximal | 523 (0.3) | 338 (0.3) | 52 (0.3) | 21 (0.3) | 112 (0.3) |
| Men | |||||
| All | 1557 (0.9) | 1095 (1.0) | 191 (1.2) | 72 (0.7) | 199 (0.5) |
| Distal | 906 (0.5) | 677 (0.6) | 128 (0.8) | 44 (0.4) | 57 (0.1) |
| Proximal | 566 (0.3) | 365 (0.3) | 50 (0.3) | 24 (0.2) | 127 (0.3) |
Abbreviation: CRC, colorectal cancer.
a
Colonoscopy after positive finding at sigmoidoscopy screening.
b
Total number of CRC cases and CRC deaths is greater than the sum of cases by tumor location because of cancer cases with unspecified tumor location.