Wendelboe Aaron

The Veterans Health Administration (VHA) uses the Electronic Surveillance System for the Early Notification of Community-based Epidemics to detect disease outbreaks and other health-related events earlier than other forms of surveillance. Although Veterans may use any VHA facility in the world, the strongest predictor of which health care facility is accessed is geographic proximity to the patient's residence. A number of outbreaks have occurred in the Veteran population when geographically separate groups convened in a single location for professional or social events. One classic example was the initial Legionnaire's disease outbreak, identified among participants at the Legionnaire's convention in Philadelphia in the late 1970s. Numerous events involving travel by large Veteran (and employee) populations are scheduled each year.

Objective

To develop an algorithm to identify disease outbreaks by detecting aberrantly large proportions of patient residential ZIP codes outside a health care facility catchment area.

The VA has employed ESSENCE for health monitoring since 2006 [1]. Epidemiologists at the Office of Public Health (OPH) monitor the VA population at the national level. The system is also intended for facility-level monitoring to cover 152 medical centers, nearly 800 community-based outpatient clinics (CBOC), and other facilities serving all fifty states, the District of Columbia, and U.S. territories. For the entire set of facilities and current syndrome groupings, investigation of the full set of algorithmic alerts is impractical for the group of monitors using ESSENCE. Signals of interest may be masked by the nationwide alert burden. Customized querying features have been added to ESSENCE, but standardization and IP training are required to assure appropriate use.

Objective

The objective was to adapt and tailor the alerting methodology employed in the Electronic Surveillance System for Early Notification of Community-Based Epidemics (ESSENCE) used by Veterans Affairs (VA) for routine, efficient health surveillance by a small, VA headquarter medical epidemiology staff in addition to a nationwide group of infection preventionists (IPs) monitoring single facilities or facility groups.

The U.S. Surgeon General's 2008 Call to Action to Prevent Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE) raised the importance of conducting surveillance for VTE. VTE comprises PE and DVT and collectively is responsible for estimated 350,000-900,000 events and 100,000-300,000 deaths annually in the U.S. However, these estimates are uncertain because no current surveillance is conducted for VTE and thus are derived from cohort studies in selected counties (which often lack racial diversity typical of the U.S.) and then generalized to the U.S population. These estimates are also limited by an inability to differentiate between incident and recurrent events and provoked and non-provoked events. In addition, non-hospitalized patients have not been included in some of these estimates. With the availability of non-invasive and highly sensitive and specific diagnostic procedures of computed tomography (CT) for PE and compression ultrasound (CUS) for DVT, and the implementation of electronic health records, the time is right to establish a surveillance system for VTE events.

Objective

The University of Oklahoma Health Sciences Center (OUHSC) is collaborating with the Centers for Disease Control and Prevention (CDC) to establish a pilot system to inform future scaled-up national surveillance for Venous Thromboembolism (VTE).