Parachute use to prevent death and major trauma related to gravitational challenge: systematic review of randomised controlled trials

Smith, GCS and J Pell BMJ 2003; 327, 1459 British Medical Journal
A tongue in cheek analysis of meta-analyses, randomised, placebo controlled trials and evidence based medicine. These authors very cleverly make a strong case for the fact that some interventions do NOT lend themselves to randomised blinded trials.But can still have a place in medicine simply because they have been seen to work. While not for a minute purporting to compare an acupuncture treatment to the life saving action of a parachute, we nevertheless would like to point out that there are some aspects of a discipline like acupuncture which will never be able to be squeezed into the confines of a double blind randomised trial, without losing something of its essence. Other aspects of acupuncture, like some of its known physiological effects, can be measured in a trial setting - however the results of these trials should never be taken to be telling the WHOLE story!



Objectives: To determine whether parachutes are effective in preventing major trauma related to gravitational challenge.
Design Systematic review of randomised controlled trials.

Data sources: Medline, Web of Science, Embase, and the Cochrane Library databases; appropriate internet sites and citation lists.
Study selection: Studies showing the effects of using a parachute during free fall.

Main outcome: measure Death or major trauma, defined as an injury severity score > 15.

Results: We were unable to identify any randomised controlled trials of parachute intervention.

Conclusions: As with many interventions intended to prevent ill health, the effectiveness of parachutes has not been subjected to rigorous evaluation by using randomised controlled trials. Advocates of evidence based medicine have criticised the adoption of interventions evaluated by using only observational data. We think that everyone might benefit if the most radical protagonists of evidence based medicine organised and participated in a double blind, randomised, placebo controlled, crossover trial of the parachute.

They conclude their discussion with a call to arms …….

“Only two options exist. The first is that we accept that, under exceptional circumstances, common sense might be applied when considering the potential risks and benefits of interventions.

The second is that we continue our quest for the holy grail of exclusively evidence based interventions and preclude parachute use outside the context of a properly conducted trial. The dependency we have created in our population may make recruitment of the unenlightened masses to such a trial difficult. If so, we feel assured that those who advocate evidence based medicine and criticise use of interventions that lack an evidence base will not hesitate to demonstrate their commitment by volunteering for a double blind, randomised, placebo controlled, crossover trial.”