From temporal expressions to symptom onset date identification in emergency department notes: a temporal information extraction process

A patient's visit to the Emergency Department (ED) starts with the triage nurse making a note of the patient's account of the reason for the visit. This triage note (TN) contains symptoms the patient is suffering from, prior treatments if any, related events and sometimes the nurse's evaluation of the situation. Public health officials may use these TNs to identify features of disease outbreaks. Here we present a system that processes triage notes, producing a timeline of events leading to the ED visit and identifying patterns in occurrence of symptoms across patients. This system is designed as an initial step in the process of automatically extracting signals/symptoms defining a disease outbreak based on the details (symptoms and temporal information) associated with ED visits