School of Medicine

This study was a structured review of existing electronic clinical and logistical records of HEMS transports created using the International Classification of Disease, Ninth Edition (ICD-9) and other diagnostic identifiers. Data were collected during HEMS patient documentation within integrated software from Golden Hour Data Systems, Inc (San Diego, CA) using an information management service that integrates clinical and dispatch data on "cloud-based" servers managed by the electronic medical recrod (EMR) providers. Data are owned by the HEMS provider. All providers agreed contractually to a deidentified data sharing protocol through the EMR provider, permitting academic research. The entire anonymous database spanned the years 2004 through 2011 and consisted of 861,284 HEMS transports. Cardiac arrests were identified by ICD-9 codes, ICD-9 text and text entry "reason for transport" inputs with the assistance of a certified medical coder. Fixed wing and ground transports were excluded. Records were excluded principally for missing pre-hospital impressions. Patients whose overall reason for transport was "trauma" were excluded.