Demographic characteristics of all enrolled patients
| Age in years, mean/median/range | 63.4/65/25–91 |
| Men, n (%) | 361 (56.3) |
| Index investigation, n (%) Full colonoscopy | 545 (85.0) |
| Flexible sigmoidoscopy+completion colonoscopy | 41 (6.4) |
| Flexible sigmoidoscopy+barium enema | 49 (7.6) |
| Flexible sigmoidoscopy+CT colonography | 6 (0.9) |
| Diverticular disease at index investigation, n (%) | 175 (27.3) |
| Bowel preparation, n (%) Good/satisfactory | 574 (89.5) |
| Poor | 27 (4.2) |
| Not stated | 40 (6.2) |
| Number of adenomas at index investigation, n (%) 1 | 517 (80.7) |
| 2 | 124 (19.3) |
| Size of adenomas at index investigation, n (%) Diminutive (≤5 mm) adenoma(s) only | 366 (57.1) |
| At least one adenoma between 6 and 9 mm | 275 (42.9) |
| Polypectomy technique, n (%) Hot biopsy | 356 (55.5) |
| Cold biopsy | 50 (7.8) |
| Cold snare | 182 (28.4) |
| Hot snare | 9 (1.4) |
| Not recorded | 44 (6.9) |
| Histological architecture of adenomas at index, n (%) Tubular | 639 (83.5) |
| Tubulovillous | 104 (13.6) |
| Villous | 3 (0.4) |
| Serrated | 15 (2.0) |
| Not retrieved | 4 (0.5) |
| Grade of dysplasia of adenomas at index, n (%) Low grade | 749 (97.9) |
| High grade | 12 (1.6) |
| Not retrieved | 4 (0.5) |
| Patients with high-grade dysplasia, tubulovillous or villous morphology at index, n (%) | 106 (16.5) |