Emergency Department (ED) triage notes are clinical notes that expand upon the chief complaint, and are included in the AHIC minimum dataset for biosurveillance.1 Clinical notes can improve the accuracy of keyword-based syndromes but require processing that addresses negated terms.2,3 The North Carolina Disease Event Tracking and Epidemiologic Collection Tool (NC DETECT) syndrome classifier searches for keywords in free-text chief complaint and triage note data for the purpose of early event detection. Initial attempts to handle negation were included in the syndrome queries beginning in August 2005. Query statements were written to identify and ignore select symptoms immediately following negated terms, such as denies fvr or no h/a. Many negated terms, however, were not addressed and continue to create false positive syndrome hits. The purpose of this pilot was to address negation with NegEx (a negation tool)4, supplemented by selected modules from the Emergency Medical Text Processor (EMTP), a chief complaint pre-processor.
Objective
The objective of this pilot study was to explore methods for addressing negation in triage notes.