b'342021 CARES Annual Report Survival OutcomesPatient Outcomes On the basis of local EMS agency protocols, 42.4% of patients were pronounced on scene after resuscitative efforts were terminated in the pre-hospital setting (Figure 16). A successful attempt at resuscitation in the field is often defined by a patients return of spontaneous circulation (ROSC). In 2021, sustained ROSC (20 consecutive minutes of ROSC, or present at transfer of care to a receiving hospital) was achieved by 27.1% of CARES patients. The rate of survival to hospital admission was 24.7% (ED outcome missing for 269 cases; 0.2%), and the rate of survival to hospital discharge was 9.1% (hospital outcome missing for 305 cases; 0.21%). 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 ScoreDescription CPC 1Good Cerebral Performance Conscious, alert, able to work and lead a normal life. Moderate Cerebral Disability CPC 2 Conscious and able to function independently (dress, travel, prepare food), but may have hemiplegia, seizures, or permanent memory or mental changes. Severe Cerebral Disability CPC 3Conscious, dependent on others for daily support because of impaired brain function (in an institution or at home with exceptional family effort). Coma, Vegetative State CPC 4Not conscious. Unaware of surroundings, no cognition. No verbal or psychological interactions with environment. CPC 5Death'