[Correspondence] Quantifying Immunoscore performance
In their Article, Franck Pagès and colleagues (May 26, p 2128)1 describe how they developed a useful Immunoscore system with patients’ baseline information to predict time to colon cancer recurrence. External validation data were used to evaluate the performance of Immunoscore. An unadjusted hazard ratio (HR) of 0·36 (95% CI 0·25–0·53; p<0·0001) for recurrence was reported in favour of high versus low Immunoscore. We note that the HR should not be interpreted as a risk ratio2–5 because hazard is not a probability measure.