Table 6. Cox regression results – relative hazards for screen-detected vs symptomatic tumours, the effect of adjustment for prognostic factors and correction for lead time, and the Freedman (199 percentage of the survival advantage of screen-detected tumours accounted for by adjustment and correction).
| Correction for lead time | Adjustment | Relative hazard (95% CI) | Freedman percentage |
|---|---|---|---|
| No | None | 0.34 (0.31–0.36) | — |
| Size and node status | 0.56 (0.50–0.61) | 46 | |
| NPI | 0.70 (0.63–0.78) | 67 | |
| Yes | None | 0.48 (0.45–0.52) | 32 |
| Size and node status | 0.90 (0.82–0.99) | 90 | |
| NPI | 1.20 (1.09–1.33) | 100 |
Abbreviations: CI=confidence interval; NPI=Nottingham Prognostic Index.