The gravitational challenge review
Jon Pike tweeted a link to an interesting study.
Parachute use to prevent death and major trauma related to gravitational challenge: systematic review of randomised controlled trials
Abstract
Objectives To determine whether parachutes are effective in preventing major trauma related to gravitational challenge.
Design Systematic review of randomised controlled trials.
…
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.
And people say scientists are overserious!
As a former skydiver with more than 400 jumps I am living proof that the whole “free fall kills” myth is bullshit. What those free fall alarmists and shills for the parachute industry conveniently fail to mention is that only something like 15%* of high altitude skydiving (typically from around 13.000 feet) involves any open parachute what so ever! Just because X happened before Y, it doesn’t follow that X caused Y. To argue that free fall is dangerous because people sometimes die after landing without a parachute is no less stupid than arguing that water is dangerous because people sometimes die after drinking water. Correlation does not equal causation. There are people who have 10 times more jumps than me who are still alive and kicking as well as plenty of people with zero jumps who died! It’s all just a ploy to get our money and take away our freedoms. Don’t fall for it! #MAGA
*Usually the last 2000 feet. or so of a jump.
That article is from 2003. Are you seriously claiming that there have been no advances in parachute science in the intervening 19 years?
@Maroon –
Furthermore, it’s from Christmas 2003. The BMJ has a bit of a tradition of running joke papers at Christmas.
To be serious for a moment, this is obviously meant as a more light-hearted way of saying the same things that people like Steven Novella have been saying about the problems with Evidence-Based Medicine (EBM), specifically the part about, focusing exclusively on randomized double-blind clinical trials without considering prior probability or taking into account everything else we know about the way the nature works (including such “irrelevant” questions as “does it violate the known laws of physics?”). I belive it was Novella who once described it as “methodolatry”. As I understand it, this was the main motivation for distinguishing Science-Based Medicine from Evidence-Based Medicine in the first place.
Where the analogy breaks down (once again, as I understand it) is this: The main problem with EBM was never false negatives (e.g. failing to demonstrate the efficacy of parachutes) but rather false positives (seeming to indicate a weak support for quack treatments that violate everything we know about physics, chemistry, biology etc.). I.e. the problem is type 1 rather than type 2 errors. It used to be a real problem that scientists would get false positives by assigning too high Bayesian priors to plausible treatments. EBM was an attempt to fix that by disregarding priors altogether, but in doing so it ended up generating false positives by taking away any disadvantage for highly implausible treatments like homeopathy or acupuncture.
I did see a paper some years ago, comparing the result of jumping out of an aircraft with or without a parachute. It found no difference in injuries or death.
I do not recall if the study was double-blinded or not. It would be easy enough, to provide some participants with a non-working parachute. The study design had the volunteers jumping out of a plane parked on the ground. I do not remember if they gave reasons for this, whether to save money or some ethics committee intervened.
The study was published in Annals of Improbable Research (AIR), if I recall correctly.
A suitable followup study might take participants up flying, but skip the jumping out part. It is well known, after all, that varying one variable at a time is good study design.
Harald
lol!
To be fair. jumping out of airplanes was probably the safest thing we did back in my skydiving days. By far the most common cause of injuries was excessive partying (Don’t look at me! I usually fell asleep before things got out of hand). We always took safety very seriously when it came to the jumping part though. Professional drivers in Norway have something called the “8 Hour Rule”, i.e. stop drinking at least 8 hours before driving. We had our own version of that called the “8 Meter Rule”, i.e. stop drinking at least 8 meters from the plane.
I’m kidding of course ;)
@#7
For moment I thought you were going to write “8 metres from the ground”!