Syndrome Definition

ESSENCE receives and analyzes data for the Military Health System’s (MHS) 9 million beneficiaries resulting in approximately 90,000 daily outpatient and emergency department visits worldwide. In May 2008, MHS released ESSENCE Version 2.0, a system-wide upgrade which includes the following enhancements: improved system security, additional reporting and display capabilities, laboratory orders, radiology orders, and the ability for users to define their own syndrome groups.

Objective

As an evolving syndromic surveillance system, ESSENCE has recently undergone some significant improvements and new additional capabilities. We present three of these impactful enhancements and evaluate their added value to military public health and preventive medicine providers and system users. Specific Version 2.0 enhancements include: (1) laboratory orders (2) radiology orders and (3) the ability for users to create their own syndrome groups for outbreak classification and detection.

The purpose of syndromic surveillance is the early identification of disease outbreaks. Classification of chief complaints into syndromes and the type of statistics used for aberration detection can affect outbreak detection sensitivity and specificity. Few data are available on the relationship between chief complaints and demographics such as gender, age, or race. For example, myocardial infarction in women would be misclassified using definitions based solely on “male” symptoms such as chest pain because women more commonly report neck, jaw, and back pain.

Objective

We evaluated the sensitivity and specificity of a gastrointestinal syndrome group using the Boston Public Health Commission syndromic surveillance system.

BioSense is a national automated surveillance system designed to enhance the nation's capability to rapidly detect and quantify public health emergencies, by accessing and analyzing diagnostic and prediagnostic health data. The BioSense system currently receives near real-time data from more than 540 civilian hospitals, as well as national daily batched data from over 1100 Department of Defense and Veterans Affairs medical facilities. BioSense maps chief complaint and diagnosis data to 11 syndromes and 78 sub-syndromes. This project was spurred by the recent detection of several clusters with chief complaints containing the term “exposure” only some of which map to current BioSense sub-syndromes. BioSense currently does not have a generic “exposure” sub-syndrome.

OBJECTIVE

To identify hospital visits with chief complaints concerning exposures, characterize them, and develop methods for detecting exposure clusters.

We report on a retrospective analysis of gastrointestinal syndrome definitions based on chief complaints and ICD9 diagnosis for gastroenteritis during the 2006-07 season of increased norovirus activity.

To compare age-group-specific correlation of influenza-like syndrome (ILS) emergency department (ED) visits with influenza laboratory data in Boston and NYC using locally defined ILS definitions.

To compare locally-developed influenza-like syndrome definitions (derived from emergency department (ED) chief complaints) when applied to data from two ISDS DiSTRIBuTE Project participants: Boston and New York City (NYC) [1].

Automated syndromic surveillance systems often classify patients into syndromic categories based on free-text chief complaints. Chief complaints (CC) demonstrate low to moderate sensitivity in identifying syndromic cases. Emergency Department (ED) reports promise more detailed clinical information that may increase sensitivity of detection. Objective: Compare classification of patients based on chief complaints against classification from clinical data described in ED reports for identifying patients with an acute lower respiratory syndrome.