16 Incidence & Demographics 2017 Dataset and Incidence of OHCA Events This report describes CARES data from the most recent calendar year, January 1 to December 31, 2017. CARES requires that an EMS Agency enter at least one complete calendar year of data and meet a patient lost to follow-up threshold of less than 1% to be included in the Annual National Report. The CARES 2017 National Reports can be viewed at: https://mycares.net/sitepages/reports2017.jsp. Descriptive statistics in this report are presented as frequencies or proportions for categorical variables, and median and interquartile ranges for continuous variables. Comparison of proportions were conducted using the chi-square test. The 2017 dataset includes 1,156 EMS Agencies and 1,304 Hospitals, and represents a population of 102.6 million, approximately 32% of the U.S. population. In 2017, 76,215 OHCA events were reported to CARES. The crude incidence of non-traumatic, worked arrests was 74.3 per 100,000, higher than the rate of 68.9 per 100,000 observed in 2016. Using 2017 census data to extrapolate to the U.S. population 4 , CARES estimates that there were approximately 242,000 EMS- treated, non-traumatic OHCAs in the United States last year. Demographics In 2017, CARES patients were predominately male (62.0%). Of the reported OHCA events, 97.2% (n=74,058) were adults and 2.8% (n=2,113) were children, 18 years and younger. The median age of OHCA patients was 64.0 years (mean: 62.0; SD: 19.5). The age distribution varied significantly across the sexes (Figure 2), with females having a higher median age of arrest (66.0 vs. 63.0 years, p