Screenee and procedure characteristics and colonoscopy performance by randomisation group (Train-Colonoscopy-Leader (TCL) and feedback groups) and study phase (procedures performed by screening centre leaders)
| The TCL group (19 endoscopists)* | The feedback group (19 endoscopists)* | |||||
|---|---|---|---|---|---|---|
| Preintervention phase, N=6217 | Early postintervention phase, N=3381 | Late postintervention phase, N=3826 | Preintervention phase, N=4766 | Early postintervention phase, N=2977 | Late postintervention phase, N=3415 | |
| Screenee variables | ||||||
| Age, mean (±SD) | 56.4 (5.4) | 56.9 (5.4) | 56.9 (5.4) | 56.7 (5.2) | 57.0 (5.3) | 57.1 (5.1) |
| Male sex—n (%) | 2237 (36.0) | 1175 (34.7) | 1525 (39.9) | 1783 (37.4) | 1123 (37.7) | 1385 (40.7) |
| Procedure variables | ||||||
| Intravenous sedation—n (%) | 4000 (64.3%) | 2011 (59.5%) | 2330 (60.9%) | 2644 (55.5%) | 1628 (54.7%) | 1877 (55.0) |
| Adequate bowel preparation†—n (%) | 5833 (93.8%) | 3240 (95.8%) | 3610 (94.4%) | 4520 (94.8%) | 2724 (91.5%) | 3185 (93.3%) |
| Total colonoscopy—n (%) | 5995 (96.4%) | 3268 (96.7%) | 3690 (96.4%) | 4631 (97.2%) | 2870 (96.4%) | 3322 (97.3%) |
| Screenees with adenoma or cancer—n (%) | 1023 (16.4%) | 812 (24.0%) | 897 (23.4%) | 898 (18.8%) | 574 (19.3%) | 719 (21.1%) |
| Screenees with polyps not removed/retrieved—n (%) | 31 (0.5%) | 20 (0.6%) | 14 (0.4%) | 26 (0.5%) | 18 (0.6%) | 25 (0.7%) |
| Screenees with proximal‡ adenoma or cancer—n (%) | 430 (6.9%) | 421 (12.4%) | 452 (11.8%) | 426 (8.9%) | 312 (10.5%) | 389 (11.4%) |
| Screenees with non-polypoid lesion§—n (%) | 112 (1.8%) | 128 (3.8%) | 143 (3.7%) | 79 (1.7%) | 45 (1.5%) | 84 (2.5%) |
| Screening centre leader performance variables | ||||||
| Number of colonoscopies, median (range) | 258 (40–898) | 182 (21–443) | 187 (20–519) | 187 (120–384) | 88 (57–296) | 124 (34–514) |
| Adenoma detection rate, mean (±SD) | 17.4% (3.2) | 25.6% (8.2) | 23.9% (4.7) | 18.5% (3.6) | 19.6% (6.5) | 20.8% (6.1) |
| Proximal‡ adenoma detection rate, mean (±SD) | 7.8% (2.6) | 13.3% (6.1) | 12.0% (4.9) | 8.6% (3.7) | 10.2% (4.9) | 10.2% (4.9) |
| Non-polypoid lesion§ detection rate, mean (±SD) | 1.8% (1.9) | 4.8% (4.5) | 3.8% (4.0) | 2.0% (2.0) | 1.5% (1.3) | 2.1% (2.2) |
| Caecal intubation rate, mean (±SD) | 96.5% (4.2) | 95.8% (4.4) | 96.3% (4.5) | 96.5% (2.7) | 95.2% (4.6) | 96.2% (4.1) |
*In the late postintervention phase, one leader in each group left the screening centre; the remaining 36 endoscopists were used for analyses.
†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.