Illustration of 28-day mortality RR reduction (DrotAA versus placebo) for each potential biomarker at baseline. The point estimates of relative risk (RR) for death in patients at lower risk and higher risk, based on statistically defined cut-offs (shown in Table 2), are indicated by open ovals and solid ovals, respectively; 95% confidence intervals (CIs) are indicated by horizontal lines. Only protein C (PC) was significantly (P < 0.05) different between the two risk groups, as indicated by the least overlap in CIs, indicating a differential benefit. P values were determined using Breslow-Day tests. AT, antithrombin; CI, confidence interval; DrotAA, drotrecogin alfa (activated); IL, interleukin; PT, prothrombin time; SOFA, Sequential Organ Failure Assessment.