Abstract Body: Objective
To describe disease-specific, ill-defined, and discordant causes of death among screened and adjudicated working-age, sudden death victims in Wake County, NC, from 2013–2015.

Background
Atherosclerosis is often assumed to be the most common disease-specific cause of sudden death. However, preliminary evidence suggests that sudden death in younger adults may arise from heterogeneous causes. To better characterize these causes, we conducted a descriptive analysis of underlying causes of death among working-age adults in one diverse North Carolina county, using data from death certificates, EMS trip reports, medical records, and autopsy reports.

Methods
Out-of-hospital sudden deaths among adults aged 18–64 were identified by EMS screening and adjudicated by three cardiologists as sudden, unexpected, out-of-hospital deaths between 2013 and 2015. Demographic and clinical characteristics were abstracted from death certificates, EMS and medical records, and autopsy reports. Primary causes of death were determined from death certificates and autopsy findings.

Results
Among 399 sudden death victims (68% male, 63% White, median age 53.5 ± 9.2 years), half were certified by a medical examiner and half by a physician on the victim’s care team, and 72 (18%) had an autopsy performed. Cardiovascular disease was the underlying cause in 204 cases (51%), of which 144 (71.0%) were attributed to atherosclerosis. Only 56 (15%) had a coronary artery disease diagnosis prior to death, with an additional 6 (1.5%) identified at autopsy. Eighty cases (20%) involved non-natural causes, pre-existing terminal illness (e.g., trauma or malignancy), or imprecise/invalid cause-of-death classifications (e.g., “natural death,” “sudden death,” or “unknown”). There were 42 (11%) victims that died of endocrine-related causes and 32 (8%) that died of pulmonary causes. Twelve cases (3.0%) showed lethal tissue drug levels on autopsy despite normal blood toxicology and no documented drug use in medical records.

Conclusion
The underlying causes of sudden death in working-age adults are diverse and not limited to atherosclerosis. Integrating autopsy, clinical, and EMS data can supplement death certificates to help identify sudden death victims and better understand causes of death which is essential to inform prevention strategies aimed at mitigating sudden death.