Explore This IssueJune 2019
Though the intent was satirical, the authors’ conclusion is certainly relevant in a research culture that values randomized controlled trials above all other types of research. The authors conclude: “When beliefs regarding the effectiveness of an intervention exist in the community, randomized trials might selectively enroll individuals with a lower perceived likelihood of benefit, thus diminishing the applicability of the results to clinical practice.”—Andres Bur, MD
Does using a parachute prevent death or major traumatic injury when jumping from an aircraft?
Bottom Line: Parachute use did not reduce death or major traumatic injury when jumping from aircraft in the first randomized evaluation of this intervention. However, the trial was only able to enroll participants on small stationary aircraft on the ground, suggesting cautious extrapolation to high altitude jumps. When beliefs regarding the effectiveness of an intervention exist in the community, randomized trials might selectively enroll individuals with a lower perceived likelihood of benefit, thus diminishing the applicability of the results to clinical practice.
Design: Randomized controlled trial.
Setting: Private or commercial aircraft between September 2017 and August 2018.
Synopsis: A total of 92 aircraft passengers aged 18 and over were screened for participation, and 23 agreed to be enrolled and were randomized. Participants jumped from an aircraft (airplane or helicopter) with a parachute versus an empty backpack (unblinded). The main outcome measure was composite of death or major traumatic injury (defined by an injury severity score higher than 15) upon impact with the ground measured immediately after landing. Parachute use did not significantly reduce death or major injury (0% for parachute vs. 0% for control). This finding was consistent across multiple subgroups. Compared with individuals screened but not enrolled, participants included in the study were on aircraft at significantly lower altitude (mean of 0.6 m for participants vs. mean of 9,146 m for non-participants) and lower velocity (mean of 0 km/h vs. mean of 800 km/h).
Citation: Yeh RW, Valsdottir LR, Yeh MW, et al. Parachute use to prevent death and major trauma when jumping from aircraft: randomized controlled trial. BMJ. 2018;363:k5094.