Rate ratios for distal colorectal cancer (CRC) by baseline sigmoidoscopy characteristics
| No of cases of distal* CRC | Distal* CRC incidence† | Rate ratio‡ | 95% CI | |
|---|---|---|---|---|
| CI, confidence interval. | ||||
| *Defined as rectum or sigmoid colon. | ||||
| †Per 100 000 person years. | ||||
| ‡Adjusted for sex, age, and family history of CRC. | ||||
| Depth of insertion (cm) | ||||
| <30 | 3 | 33.2 | 2.9 | 0.9–9.9 |
| 30–39 | 7 | 33.8 | 3.0 | 1.2–7.2 |
| 40–49 | 5 | 15.5 | 1.4 | 0.5–3.8 |
| 50–59 | 9 | 19.9 | 1.9 | 0.8–4.1 |
| 60+ | 21 | 11.0 | 1.0 | Ref. |
| Examination limited by | ||||
| Spasm/pain | 12 | 22.7 | 1.7 | 0.9–3.4 |
| Stool | 4 | 9.5 | 0.5 | 0.2–1.5 |
| Angulation | 10 | 23.5 | 1.7 | 0.8–3.5 |