Risk factors at randomisation | 2-examination group (n=701) | 1-examination group (n=763) | Both groups (n=1464) | |||
No (%) with AN*/No Pts | OR (95% CI) | No (%) with AN/No Pts | OR (95% CI) | No (%) with AN/No Pts | OR (95% CI) | |
No of adenomas† | 2.25 (0.55 to 8.35) | 3.58 (1.15 to 11.11) | 2.84 (1.37 to 5.91) | |||
1–2 | 6/343 (1.7) | 5/395 (1.3) | 11/738 (1.5) | |||
3–4 | 1/187 (0.5) | 3/197 (1.5) | 4/384 (1.0) | |||
≥5 | 5/171 (2.9) | 8/171 (4.7) | 13/342 (3.8) | |||
Size of largest adenoma‡ | 1.59 (0.39 to 5.87) | 2.25 (0.72 to 6.96) | 1.94 (0.84 to 4.40) | |||
Small (≤5 mm) | 5/246 (2.0) | 5/262 (1.9) | 10/508 (2.0) | |||
Medium (6–9 mm) | 2/236 (0.8) | 3/263 (1.1) | 5/499 (1.0) | |||
Large (≥10 mm) | 5/219 (2.3) | 8/238 (3.4) | 13/457 (2.8) | |||
Morphology§ | ||||||
Polypoid (≥10 mm) | 1.08 (0.19 to 4.38) | 1.06 (0.25 to 3.55) | 1.06 (0.38 to 2.63) | |||
Absent | 9/535 (1.7) | 12/580 (2.1) | 21/1115 (1.9) | |||
Present | 3/166 (1.8) | 4/183 (2.2) | 7/349 (2.0) | |||
Flat (<10 mm) | 0.99 (0.26 to 4.54) | − | 3.04 (1.01 to 12.11) | |||
Absent | 4/232 (1.7) | 0/255 (0) | 4/487 (0.8) | |||
Present | 8/469 (1.7) | 16/508 (3.1) | 24/977 (2.5) | |||
Depressed | − | 2.55 (0.06 to 18.34) | 1.63 (0.04 to 10.52) | |||
Absent | 12/688 (1.7) | 15/743 (2.0) | 27/1431 (1.9) | |||
Present | 0/13 (0) | 1/20 (5.0) | 1/33 (3.0) | |||
LST-G | 1.60 (0.36 to 11.57) | − | 0.77 (0.02 to 4.84) | |||
Absent | 11/663 (1.7) | 16/734 (2.2) | 27/1397 (1.9) | |||
Present | 1/38 (2.6) | 0/29 (0) | 1/67 (1.5) | |||
LST-NG | 3.04 (0.07 to 22.84) | 10.16 (2.59 to 33.84) | 6.61 (2.11 to 17.61) | |||
Absent | 11/680 (1.6) | 11/726 (1.5) | 22/1406 (1.6) | |||
Present | 1/21 (4.8) | 5/37 (13.5) | 6/58 (10.3) | |||
Pathologically advanced adenomas¶ | 1.20 (0.30 to 4.45) | 2.81 (0.91 to 9.50) | 1.92 (0.92 to 4.00) | |||
Absent | 7/439 (1.6) | 6/475 (1.3) | 13/914 (1.4) | |||
Present | 5/262 (1.9) | 10/288 (3.5) | 15/550 (2.7) | |||
Large serrated lesion (≥10 mm, Rt-sided**) | − | − | − | |||
Absent | 12/693 (1.7) | 16/755 (2.1) | 28/1448 (1.9) | |||
Present | 0/8 (0) | 0/8 (0) | 0/16 (0) | |||
Age | 1.18 (0.32 to 4.76) | 2.88 (0.86 to 12.36) | 1.88 (0.86 to 4.13) | |||
<60 years | 5/320 (1.6) | 4/370 (1.1) | 9/690 (1.3) | |||
≥60 years | 7/381 (1.8) | 12/393 (3.1) | 19/774 (2.5) | |||
Gender | 1.01 (0.27 to 4.63) | 1.67 (0.50 to 7.16) | 1.32 (0.56 to 3.00) | |||
Female | 4/235 (1.7) | 4/271 (1.5) | 8/506 (1.6) | |||
Male | 8/466 (1.7) | 12/492 (2.4) | 20/958 (2.1) | |||
Family history of CRC†† | 2.78 (0.60 to 10.59) | 2.23 (0.51 to 7.55) | 2.39 (1.07 to 5.35) | |||
Absent | 8/592 (1.4) | 12/662 (1.8) | 20/1254 (1.6) | |||
Present | 4/109 (3.7) | 4/101 (4.0) | 8/210 (3.8) |
*Any lesion with low-grade dysplasia ≥10 mm, high-grade dysplasia.
†OR; number of adenomas (≥5 vs ≤4).
‡OR; size of largest adenoma (≥10 mm vs ≤9 mm).
§Polypoid; 0-Ip, 0-Isp, 0-Is type, Flat; 0-IIa type, Depressed; 0-IIa+IIc, 0-IIc type.
¶Any low-grade dysplasia ≥10 mm, high-grade dysplasia.
**Caecum, ascending colon, transverse colon.
††First-degree relatives.
CRC, colorectal cancer; LST-G, laterally spreading tumour, granular type; LST-NG, laterally spreading tumour, non-granular type.