Investigation of an electronic emergency department information system as a data source for respiratory syndrome surveillance.

Emergency department syndromic surveillance may provide early warning of disease outbreaks due to bioterrorism or natural phenomena. The purpose of this investigation was to explore how an electronic emergency department information system could be used as a data source for respiratory syndrome surveillance. The process of data collection, entry, and transmission is described, and then a subset of data elements with potential epidemiological value is selected. The quality of the data contained in the system was evaluated by conducting a retrospective analysis of emergency department visits recorded in the system during 2001 and by reviewing clinical charts of cases with respiratory diagnoses. Diagnosis codes, discharge disposition, and demographic data were relatively complete; additional clinical data were not. Diagnosis codes were rapidly and reliably recorded. Data available in the system allows a description of emergency department visits for respiratory syndrome in terms of age, gender, location, severity of illness, and distribution in time. Encrypted data were transmitted every four hours to the health department without added work for emergency department personnel. Although significant obstacles remain, electronic emergency department information systems such as this may provide rapid, reliable data for syndromic surveillance.