Mean protein C activity over time for selected PROWESS DrotAA patients classified by timing of death. Presented are means and standard errors (SE) of protein C levels based on time of death of PROWESS  DrotAA patients. Raw values with no imputation are included. Note that not all groups are shown. DrotAA, drotrecogin alfa (activated); PROWESS, Recombinant Human Activated Protein C Worldwide Evaluation in Severe Sepsis.