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Parachute use to prevent death, trauma when jumping from aircraft (2018) [pdf]

bmj.com

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Re: Parachute use to prevent death, trauma when jumping from aircraft (2018) [pdf]

#161

Post by dang »

Related:

Parachute use to prevent death, major trauma when jumping from aircraft (2018) - https://news.ycombinator.com/item?id=30795522 - March 2022 (8 comments)

Parachute use to prevent death and major trauma: systematic review (2003) - https://news.ycombinator.com/item?id=28508084 - Sept 2021 (24 comments)

Parachute use to prevent death and major trauma when jumping from aircraft (2018) - https://news.ycombinator.com/item?id=27676727 - June 2021 (6 comments)

Parachute use to prevent death and major trauma related to gravity challenge (2003) - https://news.ycombinator.com/item?id=22788043 - April 2020 (9 comments)

Parachute use to prevent death jumping from aircraft: random controlled trial (2018) - https://news.ycombinator.com/item?id=22778832 - April 2020 (36 comments)

Parachute use to prevent death and major trauma when jumping from aircraft - https://news.ycombinator.com/item?id=18677508 - Dec 2018 (110 comments)

Parachute use to prevent death and major trauma due to gravitational challenge - https://news.ycombinator.com/item?id=4644463 - Oct 2012 (57 comments)

Re: Parachute use to prevent death, trauma when jumping from aircraft (2018) [pdf]

#162

Post by haldujai »

psychphysic wrote: post #145
haldujai wrote: post #138

I think people misunderstand what evidence based medicine is[0]. There are many types of evidence ranging from lab studies and expert opinion at the bottom to systematic reviews/meta-analyses at the top. The point being that we should strive for RCTs when possible , and that RCTs carry more weight than expert opinion or case-control. Many (I don’t have an exact number) clinical practice guidelines are based on expert…

> Many (I don’t have an exact number) clinical practice guidelines are based on expert opinion or observational studies, and are completely valid/evidence-based (it’s just weak evidence). A big problem is that humans have a preference for action, and a dislike of waiting for information. Many flawed guidelines are based on a desire to act even in the absence of evidence of benefit. "Primum non nocere" is probably the…

> Many flawed guidelines are based on a desire to act even in the absence of evidence of benefit.

Very true, I mostly intended to illustrate that many "good" or accepted guidelines are not necessarily based on randomized controlled trials as there seems to be a misconception (based on recent trending posts) that these are the only forms of "evidence" in medicine.

Some guidelines are borderline pseudoscience but pertinently guidelines are not binding. You point out the correct approach - one is entirely allowed to deviate from guidelines for good reason (i.e. no/very weak evidence, questionable benefit).

That's also the beauty of the EBM, you'll find grade & strength of recommendation in any modern guideline to help interpret them. We also have quality assessment tools like QUADAS-2 and the STARD reporting guidelines to help the reader assess quality.

> "Primum non nocere" is probably the most accepted but least respected tenant of good medical practice.

Also agree but I think EBM addresses this a lot more than the old days of science-based medicine where we did things because "they made sense" without looking at various outcome measures that sometimes reveal missed harm.

> A big problem is that humans have a preference for action, and a dislike of waiting for information.

Part of this is also by necessity due to the nature of patient encounters which have a need for decision-making.

Where the guideline is clearly poor (e.g. adrenal nodules, homeopathic follow-up at best) I disregard them but sometimes you have to err on the side of caution.

As an example I recommend pancreatic cyst follow-up per the ACR guidelines even though my (abdominal radiologist)/institutional expert opinion is they're overkill and unnecessary based on very weak and dated observational evidence. But what's the alternative, everyone just does what they want and a patient's follow-up will be variable depending on the reporting physician?

Re: Parachute use to prevent death, trauma when jumping from aircraft (2018) [pdf]

#163

Post by maxerickson »

LudwigNagasena wrote: post #115
maxerickson wrote: post #73

Earlier quoted context omitted.

Both options may be true for different cases. That's option one. Or do you insist on some particular definition of exceptional circumstances?

It’s like the difference between civil law and criminal law. In civil law the balance of probabilities is used. In criminal law the accusation should be proved beyond reasonable doubt. Option one means treating something like civil law cases. Option two means treating it like criminal law cases.

The use of common sense does not preclude the use of evidence. In fact, when good evidence is available, it suggests it.

You are arguing a distinction that does not exist.

Re: Parachute use to prevent death, trauma when jumping from aircraft (2018) [pdf]

#164

Post by lakis »

swader999 wrote: post #139

Did they even consider the speed of the plane? I suspect this is multi factorial and not just a simple case of using a parachute. More funding is needed. And please, don't call me an altitude denier, I firmly believe height has a role to play in this.

Yes. All participants (parachute and control) jumped from vehicles with 0 speed and 0.6 meters altitude ;-) I'm not joking. This is the actual study. It shows how studies can be valid statistically and shows nothing usefull for the real world.

Re: Parachute use to prevent death, trauma when jumping from aircraft (2018) [pdf]

#165

Post by [deleted] »

londons_explore wrote: post #47
gnicholas wrote: post #31

I came to leave a snarky joke comment about "in mice?", and then I remembered that mice don't actually need parachutes because their terminal velocity is roughly the same as a human using a parachute [1]. If someone actually ran the study with mice, they'd find that parachutes aren't necessary! 1: https://johnmjennings.com/can-a-mouse-survive-a-fall-from-a-...

The fact that mice don't appear to deliberately jump off high things as a way to get down tells me that they probably do get hurt... Just because they don't fall super fast doesn't mean they don't get injured because they don't have as much distance to "drop and roll" like a human does.

[deleted]

Re: Parachute use to prevent death, trauma when jumping from aircraft (2018) [pdf]

#166

Post by LudwigNagasena »

maxerickson wrote: post #163
LudwigNagasena wrote: post #115

Earlier quoted context omitted.

It’s like the difference between civil law and criminal law. In civil law the balance of probabilities is used. In criminal law the accusation should be proved beyond reasonable doubt. Option one means treating something like civil law cases. Option two means treating it like criminal law cases.

The use of common sense does not preclude the use of evidence. In fact, when good evidence is available, it suggests it. You are arguing a distinction that does not exist.

> The use of common sense does not preclude the use of evidence. In fact, when good evidence is available, it suggests it.

Nothing I said implies the opposite.

> You are arguing a distinction that does not exist.

No, the paper framed the issue as if such distinction exists. I didn’t agree with that and I don’t see why you would accuse me of that.

Re: Parachute use to prevent death, trauma when jumping from aircraft (2018) [pdf]

#167

Post by satisfice »

eviks wrote: post #33
satisfice wrote: post #24

Earlier quoted context omitted.

They state the point at the end, and it's serious point: if you were inclined to use "science" to argue against a certain intervention that some group believes in, you could do a randomized trial of that intervention, but manipulate the conditions so that the intervention is unlikely to help. The study would look right and sound right to some people. It would use all the best practices. And yet it would be a bullshit…

> manipulate the conditions so that the intervention is unlikely to help > [The study] would use all the best practices You've go some major contradiction here, since when is such manipulation "the best practice"?

"Best practices" is always bullshit, man. It's a marketing term, not an engineering or a science term. Any practice is bad or good based on the context and purpose for which it is applied.

That's the spirit in which I used the term. In plain English: you can correctly apply certain practices that are famously powerful and acceptable, while subtly undermining them in a way people might not notice, or would happily pretend not to notice if the study fits with their political position on the matter.

Re: Parachute use to prevent death, trauma when jumping from aircraft (2018) [pdf]

#168

Post by eviks »

satisfice wrote: post #167
eviks wrote: post #33

Earlier quoted context omitted.

> manipulate the conditions so that the intervention is unlikely to help > [The study] would use all the best practices You've go some major contradiction here, since when is such manipulation "the best practice"?

"Best practices" is always bullshit, man. It's a marketing term, not an engineering or a science term. Any practice is bad or good based on the context and purpose for which it is applied. That's the spirit in which I used the term. In plain English: you can correctly apply certain practices that are famously powerful and acceptable, while subtly undermining them in a way people might not notice, or would happily pre…

Then your supposedly serious point resolves to a tautology "people can bs if they do bs". Duh! This conveys nothing re. any scientific technique or using that in arguments against some intervention

Re: Parachute use to prevent death, trauma when jumping from aircraft (2018) [pdf]

#169

Post by satisfice »

eviks wrote: post #168
satisfice wrote: post #167

Earlier quoted context omitted.

"Best practices" is always bullshit, man. It's a marketing term, not an engineering or a science term. Any practice is bad or good based on the context and purpose for which it is applied. That's the spirit in which I used the term. In plain English: you can correctly apply certain practices that are famously powerful and acceptable, while subtly undermining them in a way people might not notice, or would happily pre…

Then your supposedly serious point resolves to a tautology "people can bs if they do bs". Duh! This conveys nothing re. any scientific technique or using that in arguments against some intervention

I am explaining the point of the paper. If you don’t think a parody based on that point is useful, maybe take it up with the take it up with the authors, Duh!
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