Detecting Unanticipated Increases in Emergency Department Chief Complaint Keywords

The chief complaint (CC) text field is a rich source of information, but its current use for syndromic surveillance is limited to a fixed set of syndromes defined a priori using keywords. To identify unanticipated sudden increases in word frequency, we developed a simple method that compares the frequency of every word in the CC text field on a given day against the average frequency of the same word during a baseline period. This could prove useful for situational awareness during routine surveillance and emergencies