Fig. 4
From: Sampling strategies to evaluate the prognostic value of a new biomarker on a time-to-event end-point
Power for different sample sizes of phase II (n). Scenario: censoring rate ρ = 0.4, common biomarker (25%), hazard ratio of biomarker = 1.5, sensitivity (i.e. probability of having a positive surrogate if the biomarker is positive) =0.7 and specificity (i.e. probability of having a negative surrogate if the biomarker is negative) = 0.7. Legend: CC stra surr (Case-Control stratified by surrogate), CC post surr (Case-Control post stratified by surrogate), CC event (Case-Control), CM (Counter-Matching) and SRS (simple random sampling)