Screenee and procedure characteristics and colonoscopy performance by randomisation group and study phase (procedures performed by all endoscopists at the study centres)
| Variables | The TCL group (70 endoscopists, 19 centres) | The feedback group (68 endoscopists, 19 centres) | ||||
|---|---|---|---|---|---|---|
| Preintervention phase, N=14 264 | Early postintervention phase, N=8657 | Late postintervention phase, N=10 615 | Preintervention phase, N=10 255 | Early postintervention phase, N=5987 | Late postintervention phase, N=6839 | |
| Screenee variables | ||||||
| Age, mean (±SD) | 56.3 (5.6) | 56.4 (5.8) | 56.5 (5.8) | 56.7 (5.2) | 57.0 (5.4) | 57.1 (5.2) |
| Male sex—n (%) | 5414 (38.0) | 3242 (37.4) | 4360 (41.1%) | 3853 (37.6) | 2239 (37.4) | 2786 (40.7%) |
| Procedure variables | ||||||
| Intravenous sedation—n (%) | 7944 (55.7%) | 4395 (50.8%) | 4986 (47.0%) | 5037 (49.1%) | 2848 (47.6%) | 3342 (48.9%) |
| Adequate bowel preparation*—n (%) | 13 495 (94.6%) | 8302 (95.9%) | 10 185 (95.9%) | 9635 (94.0%) | 5519 (92.9%) | 6441 (94.2%) |
| Total colonoscopy—n (%) | 13 776 (96.6%) | 8366 (96.6%) | 10 269 (96.7%) | 9839 (95.9%) | 5747 (96.0%) | 6631 (97.0%) |
| Screenees with adenoma or cancer—n (%) | 2621 (18.4%) | 1996 (23.1%) | 2495 (23.5%) | 1938 (18.9%) | 1279 (21.4%) | 1407 (20.6%) |
| Screenees with polyps not removed/retrieved—n (%) | 73 (0.5%) | 49 (0.6%) | 41 (0.4%) | 52 (0.5%) | 31 (0.5%) | 50 (0.7%) |
| Screenees with proximal† adenoma or cancer—n (%) | 1204 (8.4%) | 1037 (12.0%) | 1280 (12.1%) | 929 (9.1%) | 647 (10.8%) | 739 (10.8%) |
| Screenees with non-polypoid‡ lesion—n (%) | 230 (1.6%) | 270 (3.1%) | 399 (3.8%) | 161 (1.6%) | 109 (1.8%) | 142 (2.1%) |
| Entire screening centre performance variables | ||||||
| No. of endoscopists per centre | ||||||
| Mean (±SD) | 3.7 (2.7) | 3.7 (2.6) | 3.7 (2.6) | 3.5 (1.6) | 3.6 (1.7) | 3.6 (1.5) |
| Median (range) | 3 (1–13) | 3 (1–12) | 3 (1–13) | 4 (1–7) | 4 (1–7) | 4 (1–7) |
| Number of colonoscopies, median (range) | 633 (147–2357) | 336 (74–1787) | 380 (150–2400) | 539 (198–1097) | 300 (106–670) | 336 (204–600) |
| Adenoma detection rate, mean (±SD) | 18.4% (2.9) | 22.9% (4.7) | 24.1% (5.6) | 18.5% (3.6) | 21.6% (5.1) | 20.3% (5.1) |
| Proximal† adenoma detection rate, mean (±SD) | 8.6% (2.5) | 12.0% (4.0) | 12.5% (4.3) | 9.0% (3.2) | 11.0% (4.0) | 10.8% (3.9) |
| Non-polypoid lesion‡ detection rate, mean (±SD) | 1.6% (1.3) | 3.6% (3.4) | 4.1 (2.8) | 1.5% (1.3) | 1.7% (1.1) | 2.1 (1.7) |
| Caecal intubation rate, mean (±SD) | 96.3% (3.2) | 96.6% (2.4) | 96.5% (2.7) | 95.6% (2.5) | 95.8% (3.3) | 95.9% (3.4) |
*Bowel preparation was assessed by endoscopists.
†Proximal to the splenic flexure.
‡Non-polypoid lesion was defined as a lesion 5 mm or larger which was depressed, completely flat or elevated less than 2.5 mm.