OBJECTIVE: To characterize out-of-hospital cardiac arrest (OHCA) and factors that affect survival in a medium sized city that uses system status management for dispatch. METHODS: A retrospective cohort study of all adult OHCA patients treated by EMS between 1998 and 2001 was conducted using Utstein definitions. The primary endpoint was 1-year survival. RESULTS: Of the 1177 patients who experienced OHCA during the study period, 539 (46%) met inclusion criteria. Age ranged from 18 to 98 years (median 67). The median call-response interval was 5 min (range 0-21), and 93% were 9 min or less. There was no significant difference in the median call-response intervals between call location zip (Post) codes (p=0.07). Twenty percent of experienced ROSC (95% CI 17-23), 7% survived more than 30 days (95% CI 5-9%), and 5% survived to 1 year (95% CI 3-7%). In bivariate analysis, first rhythm and bystander CPR affected survival to 1 year. There was no significant difference in survival between male (4%) and female (7%), black (4%) and white (6%), or witnessed (7%) and unwitnessed arrest (4%). Logistic regression identified younger age, CPR initiated by bystander (19%) or first responder (41%), and presenting rhythm of VF/VT (32%) as factors associated with survival to 1 year. CONCLUSIONS: This study finds a 5% survival to 1 year among OHCA patients in Rochester, NY. A presenting rhythm of VF/VT and bystander CPR were associated with increased survival.