26 Survival Outcomes Patient Outcomes On the basis of local EMS agency protocols, 35.7% of patients were pronounced on scene after resuscitative efforts were terminated in the pre-hospital setting, an increase from the last several years (30.3% in 2015 and 32.4% in 2016). A successful attempt at resuscitation in the field is often defined by a patient’s return of spontaneous circulation (ROSC). In 2017, sustained ROSC (20 consecutive minutes of ROSC, or present at transfer of care to a receiving hospital) was achieved by 31.8% of CARES patients (Figure 16). The rate of survival to hospital admission was 28.1% (ED outcome missing for 157 cases; 0.2%), and the rate of survival to hospital discharge was 10.4% (hospital outcome missing for 173 cases; 0.2%). A majority of patients who were discharged alive had a neurologically favorable outcome, a Cerebral Performance Category (CPC) score of 1 or 2 (Table 3). Figure 16. Unadjusted pre-hospital and in-hospital OHCA patient outcomes. Table 3. Cerebral Performance Category (CPC) scores CPC Score Description CPC 1 Good Cerebral Performance Conscious, alert, able to work and lead a normal life. CPC 2 Moderate Cerebral Disability Conscious and able to function independently (dress, travel, prepare food), but may have hemiplegia, seizures, or permanent memory or mental changes. CPC 3 Severe Cerebral Disability Conscious, dependent on others for daily support because of impaired brain function (in an institution or at home with exceptional family effort). CPC 4 Coma, Vegetative State Not conscious. Unaware of surroundings, no cognition. No verbal or psychological interactions with environment. CPC 5 Death