Results
Patients, Arrests, and Progression of CPR Instructions
During the course of the trial, 5525 randomization envelopes were opened for patients presumed to be in cardiac arrest. Of these patients, 1941 (35%) met the inclusion criteria (Figure 1Figure 1Enrollment, CPR Status, and Eligibility.). The two most common reasons for exclusion were that EMS personnel found the patient to be alive without arrest or to have signs of irreversible death (in which case resuscitation by EMS was not attempted). The distribution of exclusions in the two groups was similar according to randomization status.