Injury and fatality risks in aeromedical transport: focus on prevention

Aeromedical transport (AMT) is a reliable and well-established life-saving option for rapid patient transfers to health care delivery hubs. However, owing to the very nature of AMT, fatal and nonfatal events may occur. This study reviews aeromedical incidents reported since the publication of the last definitive review in 2003, aiming to provide additional insight into a wide range of factors potentially associated with fatal and nonfatal AMT incidents (AMTIs). We hypothesized that weather and/or visual conditions, postcrash fire, aircraft make and/or type, and time of day all correlate with the risk of AMTI with injury or fatality.

Specialty databases were queried for AMTI between January 1, 2003 and July 31, 2015. Additional Internet-based resources were also used to find any additional AMTI (including non-US occurrences) to augment the event sample size available for analysis. Univariate analyses of the collected sample were then performed for association between "fatal crash or injury" (FCOI) and weather/visual conditions, aircraft type and/or make, pilot error, equipment failure, post-incident fire, time of day (6 am-7 pm versus 7 pm-6 am), weekend (Friday-Sunday) versus weekday (Monday-Thursday), season of the year, and presence of patient on board. Variables reaching significance level of P < 0.20 were included in multivariate analysis.

A total of 59 AMTIs were identified. Helicopters were involved in 52 of 59 AMTIs, with 7 of 59 fixed-wing incidents. Comparing pre-2003 data with post-2003 data, we noted a significant decrease in AMTIs per month (0.70 versus 0.39, respectively, P = 0.048), whereas the number of fatalities per year increased slightly (7.20 versus 8.26, p = n/s). In univariate analyses, abnormal weather conditions, impaired visibility, time of incident (7 pm-6 am), aircraft model/make, and post-incident fire all reached statistical significance sufficient for inclusion in multivariate analysis (P < 0.20). Factors independently associated with FCOI included post-incident fire (odds ratio, 19.0; 95% confidence interval, 1.41-255.5) and time of incident between 7 pm and 6 am (odds ratio, 11.2; 95% confidence interval, 1.29-97.2). Weather conditions, impaired visibility, and aircraft model/make were not independently associated with FCOI.

The present study supports previous observation that post-crash fire is independently associated with FCOI. However, our data do not support previous observations that weather conditions, impaired visibility, or aircraft model/make are independently predictive of fatal AMTI. In addition, this report demonstrates that flights between the hours of 7 pm-6 am may be associated with greater odds of FCOI. Efforts directed at identification, remediation, and active prevention of factors associated with AMTI and FCOI are warranted given the global increase in aeromedical transport.