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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.12 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,34 and parachutist injuries are formally recognized in the World Health Organization’s ICD-10 (international classification of diseases, 10th revision).5 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.67
Previous attempts to evaluate parachute use in a randomized setting have not been undertaken owing to both ethical and practical concerns. Lack of equipoise could inhibit recruitment of participants in such a trial. However, whether pre-existing beliefs about the efficacy of parachutes would, in fact, impair the enrolment of participants in a clinical trial has not been formally evaluated. To address these important gaps in evidence, we conducted the first randomized clinical trial of the efficacy of parachutes in reducing death and major injury when jumping from an aircraft.
Abstract
Objective To determine if using a parachute prevents death or major traumatic injury when jumping from an aircraft.
Design Randomized controlled trial.
Setting Private or commercial aircraft between September 2017 and August 2018.
Participants 92 aircraft passengers aged 18 and over were screened for participation. 23 agreed to be enrolled and were randomized.
Intervention Jumping from an aircraft (airplane or helicopter) with a parachute versus an empty backpack (unblinded).
Main outcome measures Composite of death or major traumatic injury (defined by an Injury Severity Score over 15) upon impact with the ground measured immediately after landing.
Results 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).
Conclusions 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.
The study humorously concluded that parachutes are no more effective than empty backpacks in preventing death or major injury when jumping from an aircraft. This was based on a randomized trial where participants jumped from aircraft, but it was a tongue-in-cheek study to highlight the limitations of certain types of research.
The study was conducted by having participants jump from an aircraft while wearing either a parachute or an empty backpack. However, the aircraft was stationary on the ground or at a very low altitude, making the jumps inherently safe regardless of the equipment used.
The purpose of the study was to use satire to demonstrate the potential pitfalls of randomized controlled trials and to emphasize that not all interventions can or should be tested in this manner. It aimed to provoke thought about the design and interpretation of clinical trials.
No, the study does not actually suggest that parachutes are ineffective in real-life scenarios. The study's design was intentionally flawed to make a point about research methodologies. Parachutes are indeed effective in preventing injury and death when used in actual high-altitude jumps.
The study highlights the importance of context and appropriate study design in research. It serves as a reminder that results from studies must be interpreted carefully, considering the practical realities and limitations of the research methods used.