Risk of colorectal cancer according to time since single or most recent negative colonoscopy
| History of screening colonoscopy | Odds ratio (95% CI) | |||
|---|---|---|---|---|
| Cases | Controls | Adjusted for age and sex | Adjusted for multiple covariates* | |
| (n = 380) | (n = 485) | |||
| *Adjusted for age, sex, education, participation in general health screening examination, family history of colorectal cancer, smoking, body mass index, ever regular use of NSAIDs, ever regular use of HRT. | ||||
| CI, confidence interval; HRT, hormone replacement therapy; NSAID, non-steroidal anti-inflammatory drug. | ||||
| No previous colonoscopy | 350 (92.1%) | 351 (72.4%) | 1.00 Reference | 1.00 Reference |
| Single or multiple colonoscopies, last negative colonoscopy, any age | ||||
| Any time ago | 30 (7.9%) | 134 (27.6%) | 0.22 (0.14 to 0.34) | 0.26 (0.16 to 0.40) |
| 1–2 years ago | 7 (1.8%) | 50 (10.3%) | 0.13 (0.06 to 0.30) | 0.16 (0.07 to 0.36) |
| 3–4 years ago | 8 (2.1%) | 31 (6.4%) | 0.26 (0.12 to 0.58) | 0.29 (0.13 to 0.68) |
| 5–9 years ago | 5 (1.3%) | 23 (4.7%) | 0.21 (0.08 to 0.57) | 0.25 (0.09 to 0.69) |
| 10–19 years ago | 5 (1.3%) | 17 (3.5%) | 0.29 (0.11 to 0.80) | 0.33 (0.12 to 0.91) |
| 20+ years ago | 5 (1.3%) | 13 (2.7%) | 0.38 (0.13 to 1.09) | 0.46 (0.16 to 1.32) |
| Single negative colonoscopy, any age | ||||
| Any time ago | 22 (5.8%) | 83 (17.1%) | 0.27 (0.16 to 0.43) | 0.30 (0.18 to 0.50) |
| 1–4 years ago | 8 (2.1%) | 41 (8.5%) | 0.19 (0.09 to 0.42) | 0.21 (0.09 to 0.47) |
| 5+ years ago | 14 (3.7%) | 42 (8.7%) | 0.33 (0.18 to 0.62) | 0.39 (0.21 to 0.73) |
| Multiple colonoscopies, last negative colonoscopy, any age | ||||
| Any time ago | 7 (1.8%) | 50 (10.3%) | 0.14 (0.06 to 0.31) | 0.16 (0.07 to 0.37) |
| 1–4 years ago | 6 (1.6%) | 39 (8.0%) | 0.15 (0.06 to 0.36) | 0.18 (0.07 to 0.44) |
| 5+ years ago | 1 (0.3%) | 11 (2.3%) | 0.09 (0.01 to 0.69) | 0.11 (0.01 to 0.84) |
| Single or multiple colonoscopies, last negative colonoscopy <55 years | ||||
| Any time ago | 13 (3.4%) | 38 (7.8%) | 0.35 (0.18 to 0.66) | 0.45 (0.23 to 0.88) |
| 1–4 years ago | 4 (1.1%) | 10 (2.1%) | 0.51 (0.16 to 1.66) | 0.58 (0.17 to 1.93) |
| 5+ years ago | 9 (2.4%) | 28 (5.8%) | 0.34 (0.16 to 0.73) | 0.41 (0.19 to 0.90) |
| Single or multiple colonoscopies, last negative colonoscopy 55–64 years | ||||
| Any time ago | 7 (1.8%) | 49 (10.1%) | 0.14 (0.06 to 0.32) | 0.17 (0.08 to 0.39) |
| 1–4 years ago | 4 (1.1%) | 29 (6.0%) | 0.15 (0.05 to 0.42) | 0.18 (0.06 to 0.51) |
| 5+ years ago | 3 (0.8%) | 20 (4.1%) | 0.14 (0.04 to 0.49) | 0.17 (0.05 to 0.58) |
| Single or multiple colonoscopies, last negative colonoscopy 65+ years | ||||
| Any time ago | 10 (2.6%) | 47 (9.7%) | 0.21 (0.11 to 0.42) | 0.21 (0.10 to 0.44) |
| 1–4 years ago | 7 (1.8%) | 42 (8.7%) | 0.14 (0.06 to 0.33) | 0.16 (0.07 to 0.39) |
| 5+ years ago | 3 (0.8%) | 5 (1.0%) | 0.46 (0.11 to 1.99) | 0.51 (0.12 to 2.21) |