Fig. 3. Kaplan-Meier plot demonstrating the fraction of patients in the interaction study remaining free of emetic events during the first 24 h after surgery in the ondansetron (diamonds), CP-122,721 (triangles), and combination (squares) groups. The difference between the ondansetron-alone group and the two groups receiving CP-122,721, either alone or in combination with ondansetron, was significant (P < 0.05) with respect to the number of events and the time to occurrence of emesis.