October 2010) at an urban academic hospital with physically and administratively separate adult and pediatric EDs. We collected weekly data from GFT for the city of Baltimore, ED CDC reported standardized influenza-like illness (ILI) data, laboratory-confirmed influenza data and ED crowding indices (including patient volume, number of elopements, waiting room time and length of stay for admitted and discharged patients). Pediatric and adult data were analyzed separately using crosscorrelation with GFT.