OBJECTIVES: Prior efforts have linked field endotracheal intubation (ETI) with increased out of hospital (OOH) time, but it is not clear if the additional time delay is due to the procedure, patient acuity, or transport distance. We sought to assess the difference in OOH time among trauma patients with and without OOH-ETI after accounting for distance and other clinical variables. METHODS: Retrospective cohort analysis of trauma patients 14 years or older transported by ground or air to one of two Level 1 trauma centers from January 2000 to December 2003. Geographical data were probabilistically linked to trauma registry records for transport distance. Trauma registry OOH time (interval from 9-1-1 call to hospital arrival) was validated against a subset of linked ambulance records using Bland-Altman plots and tested by using the Spearman rank correlation coefficient. Based on the validation, the sample was restricted to patients with OOH time 100 minutes or less. The propensity for OOH-ETI was calculated by using field vital signs, demographics, mechanism, transport mode, comorbidities, Abbreviated Injury Scale head injury 3 or greater, injury severity score, blood transfusion, and major surgery. Multivariable linear regression (outcome = total OOH time) was used to assess the time increase (minutes) associated with OOH-ETI after adjusting for distance, propensity for OOH-ETI, and mode of transport. RESULTS: A total of 8,707 patients were included in the analysis, of which 570 (6.5%) were intubated in the field. Adjusted only for distance, OOH times averaged 6.1 minutes longer (95% CI 4.2-7.9) among patients intubated with RSI. After including other covariates, OOH time was 10.7 minutes (95% CI 7.7-13.8) longer among patients with RSI and 5.2 minutes (95% CI 2.2-8.1) longer among patients with conventional ETI. The time difference was greatest farther from the hospital. CONCLUSIONS: Patients with OOH-ETI have increased total OOH time, especially among those using RSI, even after accounting for distance and other clinical factors. Injured patients may benefit from airway management techniques that require less time for execution.