Epidemiology of adverse events in air medical transport.

Objectives: This observational study determined frequency and describes all-cause adverse event epidemiology in a large air medical transport system.

Methods: Records of a mandatory reporting system were reviewed and a data set containing all of the patient care records was searched to identify aviation- and non-aviation-related adverse events. Two reviewers independently identified adverse events and categorized them using an established taxonomy. Descriptive statistics were used to report adverse events, with frequency calculated per 1,000 flights and 1,000 hours flown.

Results: Between January 1, 2002, and June 30, 2005, there were 1,447 reports, of which 598 included an adverse event. Case-finding identified an additional 125. A complete report was available in 680 of 723 (94.1%) events. There were 58,956 flights and 103,632 hours flown during the study period, for a rate of 11.53 adverse events per 1,000 flights (95% CI = 10.7 to 12.4 adverse events) or 6.56 per 1,000 hours flown (95% CI = 6.1 to 7.1 adverse events). The frequencies of events by category were as follows: communication (229; 33.7%), transport vehicle (143; 21.0%), medical equipment (88; 12.9%), patient management (77; 11.4%), clinical performance (68; 10.0%), weather (30; 4.4%), unclassified (24; 3.5%), and patient factors causing death (21; 3.1%). There was possible patient harm in 117 events.

Conclusions: Air medical transport is associated with a low incidence of adverse events and possible patient harm. Communication problems were the most common cause of an event. Determining event epidemiology is necessary to identify modifiable factors, propose solutions to decrease the adverse events, and direct future efforts to improve safety.