SUDDEN Research Aims

Our research interest in SUDDEN is to quantify the incidence of out-of-hospital sudden unexpected death (OHSUD), as well as to study the clinical and behavioral risk factors that lead to premature sudden death in the younger adult population. In doing so, we adopt a broad definition of sudden unexpected death that does not limit the study to certain populations or potentially biased ascertainment methods. This approach will identify both cardiac and non-cardiac causes of OHSUD and underlying risk factors. We are interested in finding gaps in our current knowledge as well as healthcare systems that might be effectively targeted to reduce the burden of sudden unexpected death. Using a population based approach in diverse populations, we capture high-risk individuals who are likely to be missed by prospective cohorts and clinical trials.

Our research team is a dynamic group consisting of cardiology and epidemiology faculty at UNC who mentor interested researchers from various backgrounds. We are committed to providing a unique and worthwhile research experience. Our project leaders provide guidance in understanding clinical research, study design and implementation, and publication of findings.

So far, our team has presented their findings at distinguished national and international meetings in the field of cardiology and public health, including the American Heart Association, European Society of Cardiology, American College of Cardiology, American Public Health Association and EuroPRevent.

Defining the Knowledge Gap

Calls for nationwide, systematic data collection on out-of-hospital sudden unexpected death (OHSUD) victims has gone unheeded for years and the true incidence of OHSUD is unknown. In the past, sudden unexpected death has been falsely synonymous with sudden cardiac death. As a result of this, case inclusion criteria focused on victims whose deaths were witnessed or were last seen alive within 24 hours of death. This methodology likely misses vulnerable populations, such as victims who are socially isolated. The focus on sudden cardiac death as the main driver of all sudden death ignores other etiologies and mischaracterizes risk factors. As a result, prevention programs have been largely ineffective.

Bridging the Knowledge Gap

The SUDDEN project systematically captures all cause OHSUD cases. This enables consistent calculation of incidence rates in a community, determination of the true risk factors of OHSUD, and description of those risk factors geographically by, race, gender, socioeconomic status, and other variables. This process will focus prevention efforts on modifiable risk factors and allow measurement of effectiveness of these prevention strategies at the community level.

Innovation

This is the first population based study of out-of-hospital sudden unexpected death in which cases are not restricted by assumptions about cause or circumstance of death. We capture vulnerable populations of socially isolated individuals, many of which die at home unwitnessed, that have been neglected by previous studies. SUDDEN researchers recognize the heterogeneity of sudden death victims. Many studies to date have largely focused on homogeneous populations. North Carolina is a racially and economically diverse state and studying its residents will fill a critical need for studies on underserved and underrepresented populations.

Changes in vital statistics management, emergency medical services (EMS) data collection standards, and healthcare information systems over the past few years provided the environment to evaluate all deaths and procure records in an efficient and timely manner. These advances permit much more rigorous screening and case ascertainment processes to define and describe study subjects.

The North Carolina Bureau of Vital Records electronically records death certificate data allowing efficient screening for potential sudden deaths based on age, location, and manner of death. Data linkage software developed by the CDC enables matching death certificate data and EMS records quickly and efficiently.

The National EMS Information System (NEMSIS) is a nationwide EMS clinical record standard that will enable consistent procurement of EMS data among counties in North Carolina.

Advances in geocoding give rise to better analysis of sudden unexpected death “hot spots”. Incidence heat maps, based on geocoded EMS location data, facilitate geographically focused prevention strategies.

The Affordable Care Act (ACA) and the EHR Incentive Program of Medicare and Medicaid provide healthcare organizations with incentives to adopt and improve electronic health record systems. Data extraction from paper health records is tedious and time consuming. The move to EHR is expediting the data extraction process and will facilitate more consistent data collection.