Researchers from Harvard Medical School, UCLA, University of Michigan showed in a randomized controlled experiment that the use of a parachute made no difference in the number of deaths or injuries of people jumping out of an arirplane.
To determine if using a parachute prevents death or major traumatic injury when jumping from an aircraft a randomized controlled trial was carried out. In private or commercial aircraft between September 2017 and August 2018, 92 aircraft passengers aged 18 and over were screened for participation. Of those 23 agreed to be enrolled and were randomized.
The design was simple, namely the authors used an intervention which entailed jumping from an aircraft (airplane or helicopter) with a parachute versus an empty backpack (unblinded).
As main outcome measures, the composite of death or major traumatic injury (defined by an Injury Severity Score over 15) upon impact with the ground was measured immediately after landing.
The results show that parachute use did not significantly reduce death or major injury (0% for parachute v 0% for control; P>0.9). 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 v mean of 9146 m for non-participants; P<0.001) and lower velocity (mean of 0 km/h v mean of 800 km/h; P<0.001).
The authors conclude that 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.
Parachutes are routinely used to prevent death or major traumatic injury among individuals jumping from aircraft. However, evidence supporting the efficacy of parachutes is weak and guideline recommendations for their use are principally based on biological plausibility and expert opinion. Despite this widely held yet unsubstantiated belief of efficacy, many studies of parachutes have suggested injuries related to their use in both military and recreational settings, and parachutist injuries are formally recognized in the World Health Organization’s ICD-10 (international classification of diseases, 10th revision).This could raise concerns for supporters of evidence-based medicine, because numerous medical interventions believed to be useful have ultimately failed to show efficacy when subjected to properly executed randomized clinical trials.
Representative study participant jumping from aircraft with an empty backpack.
This individual did not incur death or major injury upon impact with the ground.
Here’s a link to the article. https://www.bmj.com/content/363/bmj.k5094