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Parachute use to prevent death and major trauma when jumping from aircraft

bmj.com

111–120 of 127 posts

Re: Parachute use to prevent death and major trauma when jumping from aircraft

#113
post #3

Earlier quoted context omitted.

It's also essential to read the first cited article ( https://www.bmj.com/content/327/7429/1459?ijkey=3b8c1a70a8d2... ) which very much inspired this paper and is also quite a bit funnier.

$37 for 1 day access to download the paper. If that's not part of the satire, I don't know what it is.

Thankfully at least bmj still has a real website. Most of the elsevier journals have moved on to a 'web app' design for journal articles and IEEEXplore has as well. These load and display absolutely no article information until you successfully run all of their third party code (only works in latest Chrome and FF). That means you can't even get the DOI from the page for sci-hub. All you get is the crappy little 'loading' spinners.

Re: Parachute use to prevent death and major trauma when jumping from aircraft

#114
post #8

Earlier quoted context omitted.

I've done over 900 jumps so I can fill you in, no references ATM because I'm on my phone. If you jump with a parachute, you will see chance of death go from 0% at zero feet, to approximately 100% at 35 feet. From there, it will remain near 100% until you reach about 600 feet, which is about the minimum distance it takes a parachute to open. Above 1000 feet and chance of death floors out near 0%

Will jumping from high enough without a parachute ever decrease the odds of death than they the odds of death at a lower altitude?

Theoretically, once you're high enough that you reach terminal velocity, any additional altitude does not increase your speed but does increase your time in the air, potentially giving you more time to navigate towards a more favorable landing site (evergreen grove, mountainside covered in deep snow, pile of 45 mattresses that happens to be outside, etc).

Re: Parachute use to prevent death and major trauma when jumping from aircraft

#116

A coworker of mine once made this proposal. 5 of us would start a company. The company would buy key man insurance for everyone, then go on a company team building trip. On this trip, we'd all skydive, but one of the 5 parachutes would be non-functional...Profit! This coworker of mine soon after left the company by storming out of the meeting room and slamming the door, then took up playing online poker for a living.

Key man insurance policies explicitly exclude parachute jumps.

I know because one of the founders of the company I work for used to jump, and he had to give up his hobby for that reason.

Re: Parachute use to prevent death and major trauma when jumping from aircraft

#117
In case anyone else got curious about parachuting injury statistics, Google found me this (also cited by the article):

"Parachuting injuries: a study of 110,000 sports jumps", 1987, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1478603/

All 6 deaths they observed, were either failures to activate the parachute (4 cases), or parachute malfunction (2 cases).

Re: Parachute use to prevent death and major trauma when jumping from aircraft

#118

Would you indicate this is a satirical article? Half the time I was looking for jump height or understanding if adding parachutes to commercial aircraft that suddenly experienced breakage such as a missile would improve passenger survival.

"The PARACHUTE trial satirically highlights some of the limitations of randomized controlled trials."

Re: Parachute use to prevent death and major trauma when jumping from aircraft

#119
post #30

Earlier quoted context omitted.

$37 for 1 day access to download the paper. If that's not part of the satire, I don't know what it is.

That might be the suggested amount, and it is a great paper, but I think you are allowed to donate less if you choose: http://sci-hub.tw/10.1136/bmj.327.7429.1459

[deleted]

Re: Parachute use to prevent death and major trauma when jumping from aircraft

#120
Some comments have touched on a few of these points but I’ll try to bring them together. So first, yes the headline is a joke (BMJ Xmas has satirical content), but it also has a history beyond the immediate point of the paper—that sometimes RCTs can’t accrue properly to a control arm to fairly evaluate an intervention.

Quick points:

   - There’s a history to this analogy and paper within
     biomedicine and this journal (BMJ) from a 2003 article,
     which I’ll get to.

   - Parachutes are a dangerous metaphor in medicine, 
     where almost nothing has an absolute risk reduction 
     of >99% (note: not 100% because, yes, a handful 
     of people have survived falling from altitude without 
     a parachute), especially over the time-frame 
     of a matter of hours.

   - This should not be a call to stop attempting RCTs 
    (which is the conclusion some commenters have made), 
    but an exhortation to find ways to create better ones 
    when conditions are challenging. Frequently, objections 
    to doing an RCT because “how could we withhold X 
    from the control arm!”, are not as obvious once 
    the data are in.
Some background: beyond Retraction Watch looking for outright fraud, there’s a movement toward opening trial data for analysis because abuses in RCT design/analysis/reporting have gotten more criticism and attention lately. This is happening at the same time as the FDA has been moving toward lower/faster evidentiary standards for approval (see Sarepta controversy and general guidance in 21st Century Cures Act to allow drugs to market with earlier phase evidence and based on “surrogates” like was the tumor 2in vs 3in bigger vs hard endpoints like “did this person die later than the control”), so it couldn’t come at a better time.

The broader point is that the 2003 “parachute” article in the same journal (BMJ), was frequently incorrectly understood / used.

While “parachutes” makes an easily understandable headline, it is almost totally unrelated to the field of medicine where we rarely have a shot at doing something as obviously lifesaving as making someone hit the ground at 10 mph vs 120 mph. The problem is that people have cited the 2003 paper mentioned in the thread to justify a number of interventions that ended up not being better than prior care. The interventions were started in good faith because was “obvious” to their creators that doing X would be helpful (spoiler: it usually wasn’t or wasn’t that beneficial).

A lot of this is cribbed from Vinay Prasad, who has a twitter thread about this: https://twitter.com/VPplenarysesh/status/1073298754298556416

He is a controversial figure, but I think he does a good job of hammering home some important skepticism about a great deal of medical literature and practice to a broad audience.

I’d appreciate hearing objections to the above, btw.

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