Automated detection of adverse events using natural language processing of discharge summaries

J Am Med Inform Assoc. 2005 Jul-Aug;12(4):448-57. doi: 10.1197/jamia.M1794. Epub 2005 Mar 31.


Objective: To determine whether natural language processing (NLP) can effectively detect adverse events defined in the New York Patient Occurrence Reporting and Tracking System (NYPORTS) using discharge summaries.

Design: An adverse event detection system for discharge summaries using the NLP system MedLEE was constructed to identify 45 NYPORTS event types. The system was first applied to a random sample of 1,000 manually reviewed charts. The system then processed all inpatient cases with electronic discharge summaries for two years. All system-identified events were reviewed, and performance was compared with traditional reporting.

Measurements: System sensitivity, specificity, and predictive value, with manual review serving as the gold standard.

Results: The system correctly identified 16 of 65 events in 1,000 charts. Of 57,452 total electronic discharge summaries, the system identified 1,590 events in 1,461 cases, and manual review verified 704 events in 652 cases, resulting in an overall sensitivity of 0.28 (95% confidence interval [CI]: 0.17-0.42), specificity of 0.985 (CI: 0.984-0.986), and positive predictive value of 0.45 (CI: 0.42-0.47) for detecting cases with events and an average specificity of 0.9996 (CI: 0.9996-0.9997) per event type. Traditional event reporting detected 322 events during the period (sensitivity 0.09), of which the system identified 110 as well as 594 additional events missed by traditional methods.

Conclusion: NLP is an effective technique for detecting a broad range of adverse events in text documents and outperformed traditional and previous automated adverse event detection methods.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Academic Medical Centers
  • Adverse Drug Reaction Reporting Systems
  • Hospitals, Urban
  • Humans
  • Medical Audit / methods
  • Medical Errors* / statistics & numerical data
  • Medical Records Systems, Computerized
  • Natural Language Processing*
  • New York City
  • Patient Discharge*
  • Vocabulary, Controlled