During the U.S. response to the Haiti Earthquake in January 2010, patient demographic and clinical treatment data were collected by ESF-8 responders through the EMR. Data were collected throughout the patient experience during registration, triage, treatment and discharge. Inclusion criteria for encounter records in the main analysis were entered into the EMR between January 18, 2010, and February 22, 2010, encounter occurred at one of the HHS sites in Haiti and data downloaded no later than February 23, 2010. Data were then analyzed in order to identify potential emerging conditions and operational medical needs during the entire response.