Demographic and colonoscopy characteristics for the 35 918 study participants*
| Characteristic | All (N=35 918) | Women (N=22 164) | Men (N=13 754) |
|---|---|---|---|
| Age, years | |||
| Range | 40–66 | 40–66 | 40–66 |
| Mean (SD) | 55.6 (5.2) | 55.6 (5.1) | 55.6 (5.3) |
| Age group, n (%) | |||
| 40–49 | 3606 (10.0) | 2125 (9.6) | 1481 (10.8) |
| 50–54 | 11 000 (30.6) | 6818 (30.8) | 4182 (30.4) |
| 55–59 | 12 379 (34.5) | 7788 (35.1) | 4591 (33.4) |
| 60–66 | 8933 (24.9) | 5433 (24.5) | 3500 (25.4) |
| Family history of CRC, n (%) | |||
| None | 29 021 (80.8) | 17 846 (80.5) | 11 175 (81.2) |
| One first-degree relative ≥60 years of age with CRC | 4798 (13.4) | 3000 (13.5) | 1798 (13.1) |
| One first-degree relative <60 years of age with CRC | 1809 (5.0) | 1121 (5.1) | 688 (5.0) |
| Two first-degree relatives with CRC | 290 (0.8) | 197 (0.9) | 93 (0.7) |
| Smoking history, pack-years†, n (%) | |||
| None | 20 240 (56.4) | 13 737 (62.0) | 6503 (47.3) |
| <10 | 4755 (13.2) | 3291 (14.8) | 1464 (10.6) |
| 10–19 | 4576 (12.7) | 2663 (12.0) | 1913 (13.9) |
| ≥20 | 6347 (17.7) | 2473 (11.2) | 3874 (28.2) |
| Diabetes mellitus, n (%) | |||
| No | 34 478 (96.0) | 21 404 (96.6) | 13 074 (95.1) |
| Yes | 1440 (4.0) | 760 (3.4) | 680 (4.9) |
| BMI (kg/m2), n (%) | |||
| <25 | 11 439 (31.9) | 8258 (37.3) | 3181 (23.1) |
| 25–29 | 16 548 (46.1) | 9190 (41.5) | 7358 (53.5) |
| ≥30 | 7931 (22.1) | 4716 (21.3) | 3215 (23.4) |
| Regular aspirin use, n (%) | |||
| No | 28 960 (80.6) | 18 110 (81.7) | 10 850 (78.9) |
| Yes | 4623 (12.9) | 2590 (11.7) | 2033 (14.8) |
| Not available | 2335 (6.5) | 1464 (6.6) | 871 (6.3) |
| Total colonoscopy, n (%) | 34 469 (96.0) | 21 078 (95.1) | 13 391 (97.4) |
| Adequate bowel preparation‡, n (%) | 33 909 (94.4) | 20 942 (94.5) | 12 967 (94.3) |
| Intravenous sedation, n (%) | 20 850 (58.1) | 13 565 (61.2) | 7380 (53.7) |
| Main colonoscopy findings, n (%) | |||
| None | 14 415 (40.1) | 9601 (43.3) | 4814 (35.0) |
| Non-neoplastic abnormalities | 14 594 (40.6) | 9171 (41.4) | 5423 (39.4) |
| Non-advanced neoplasia§ | 4365 (12.2) | 2207 (10.0) | 2158 (15.7) |
| Advanced neoplasia¶ | 2544 (7.1) | 1185 (5.3) | 1359 (9.9) |
*Because of rounding, percentages may not total 100.
†Regardless of current smoking status.
‡Bowel preparation was assessed by endoscopists.
§Includes 232 patients with polyps <10 mm in size that were not removed or retrieved.
¶Advanced neoplasia was defined as a cancer or adenoma that was ≥10 mm in diameter, had high-grade dysplasia, had a villous component, or any combination thereof.
BMI, Body Mass Index; CRC, colorectal cancer.