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

bmj.com

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

#2
Remember to reard the linked editorial for context: https://blogs.bmj.com/bmj/2018/12/13/we-jumped-from-planes-w...

> We conducted the PARACHUTE trial to illustrate the perils of interpreting trials outside of context. When strong beliefs about the standard of care exist in the community, often only low risk patients are enrolled in a trial, which can unsalvageably bias the results, akin to jumping from an aircraft without a parachute. Assuming that the findings of such a trial are generalisable to the broader population may produce disastrous consequences.

>Before you jump to the conclusion that we’re suggesting we jettison RCTs from clinical research, let us clarify that that is not our intention. In an ideal world, new interventions would always be carefully evaluated through rigorous RCTs before widespread adoption. But when pre-existing convictions about an untested intervention affect the population enrolled, even a well conducted RCT can provide misleading results. Without careful attention to context, extrapolating findings from such an RCT to the patient in front of us may be, well, a leap too far.

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

#3
post #2

Remember to reard the linked editorial for context: https://blogs.bmj.com/bmj/2018/12/13/we-jumped-from-planes-w... > We conducted the PARACHUTE trial to illustrate the perils of interpreting trials outside of context. When strong beliefs about the standard of care exist in the community, often only low risk patients are enrolled in a trial, which can unsalvageably bias the results, akin to jumping from an aircraft w…

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.

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

#4
>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; PThis is an amusing didactic example of how the "fine print" can invalidate a study's conclusion.

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

#8

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.

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%

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

#9
post #5

Please fix the title. It's misleading. The linked article in no way claims that "Parachutes prevent death when jumping from aircraft".

Well, maybe it does if you correct for the obvious errors in the statistical analysis. How did this get through peer review? I was particularly bothered by this sentence: "A P value greater than 0.05 was statistically significant."

Presumably they meant "less than", but it's hard to trust any of their conclusions with such sloppy attention to detail.

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

#10

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.

Anecdotally I find the slow realization that something is satire to be an integral part of it's entertainment value.
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