Figure 1.

Receiver operator characteristic curve for continuous veno-venous hemofiltration (CVVH) duration. A receiver operating characteristic curve was used to assess the best cutoff for time to hemofiltration-filter clotting to predict a positive PF4 test. The arrow shows that a 6-hour duration of CVVH session is the most accurate cutoff (sensitivity 71%, specificity 85%, and area under the curve 0.83).