Table 4.
Estimation of 10-year CRC risk reduction and numbers of people needed to invite for screening colonoscopy (intention-to-screen analysis) and numbers of people needed to undergo screening colonoscopy (adjusted per-protocol analysis) to prevent one CRC, assuming various degrees of mean delay in cancer registration in the NordICC trial
| Analysis | Metric | Assumed mean delay in cancer registration | |||
|---|---|---|---|---|---|
| Nonea | 1 year | 2 years | 3 years | ||
| Intention-to-screen | 10-year risk difference | 0.22% (0.07–0.37%) | 0.29% | 0.44% | 0.88% |
| Number needed to invite | 455 (270–1429) | 345 | 227 | 114 | |
| Adjusted per-protocol | 10-year risk difference | 0.38% (0.20–0.58%) | 0.51% | 0.76% | 1.52% |
| Number needed to scope | 263 (172–500) | 197 | 132 | 66 |