Researchers Show Parachutes Don't Work, But There's A Catch (npr.org)

Reader Beeftopia shares a report: Research published in a major medical journal concludes that a parachute is no more effective than an empty backpack at protecting you from harm if you have to jump from an aircraft. But before you leap to any rash conclusions, you had better hear the whole story. The gold standard for medical research is a study that randomly assigns volunteers to try an intervention or to go without one and be part of a control group. For some reason, nobody has ever done a randomized controlled trial of parachutes. In fact, medical researchers often use the parachute example when they argue they don't need to do a study because they're so sure they already know something works. Cardiologist Robert Yeh, an associate professor at Harvard Medical School and attending physician at Beth Israel Deaconess Medical Center, got a wicked idea one day. He and his colleagues would actually attempt the parachute study to make a few choice points about the potential pitfalls of research shortcuts.

They started by talking to their seatmates on airliners. [...] In all, 23 people agreed to be randomly given either a backpack or a parachute and then to jump from a biplane on Martha's Vineyard in Massachusetts or from a helicopter in Michigan. Relying on two locations and only two kinds of aircraft gave the researchers quite a skewed sample. But this sort of problem crops up frequently in studies, which was part of the point Yeh and his team were trying to make. Still, photos taken during the experiment show the volunteers were only too happy to take part. The drop in the study was about 2 feet total, because the biplane and helicopter were parked. Nobody suffered any injuries. Surprise, surprise. So it's technically true that parachutes offered no better protection for these jumpers than the backpacks.

Comments

This

[Anonymous Coward]

is the dumbest fucking thing I've read today.

Re:This

[Zocalo]

And from this I can conclude that either you did not actually read it, failed to comprehend what you read, or (just possibly) really took issue with how they presented their point, despite the Christmas issue of BMJ being intentionally lighthearted.

Hint: this has nothing to do with people jumping out of planes and everything to do with the extent that medical researchers assume things are so rather than actually demonstrate that is the case.

Re:This

[MikeDataLink]

is the dumbest fucking thing I've read today.

Then you quite simply do not understand the point of it smarty pants.

At 2ft the parachute provided no better protection than an empty backpack. This is a silly of course, but the point is that in medical research when shortcuts are taken they miss the point and come to a conclusion like this on something that actually DOES matter.

It's an analogy to help the layman understand. Get with the program.

Re:This

[ceoyoyo]

"medical researchers assume things are so rather than actually demonstrate that is the case."

I disagree. The authors of this study went out of their way to get a null result. You don't do that in real life, because you won't get published. You might be tempted to go out of your way to get a *positive* result. The main point of the article is that medical *practitioners* (also journalists, the public, administrators) read a summary, skip the details, and make undue assumptions.

The conclusion of the paper has a bit of an odd line:

"When beliefs regarding the effectiveness of an intervention exist in the community, randomized trials might selectively enroll individuals with a lower perceived likelihood of benefit, thus diminishing the applicability of the results to clinical practice."

In my experience, it's usually the opposite. Large RCTs are usually sponsored by pharma companies, and they craft inclusion criteria to give the greatest chance of finding an effect. The results are valid, in the population studied, but it's very easy for end users of the research to generalize that to "X is effective for treating Y."

Re: This

[Darinbob]

This was done as an example to the medical community on problems with research studies and results. A teaching moment rather than an actual study with practical outcomes.

Re:This

[perpenso]

is the dumbest fucking thing I've read today.

It seems you don't use twitter :-)

Re:This

[rtb61]

I know exactly that kind of example, used in real life and trumpeted all over the place by corporate main stream media, backed by professionals (true scumbags of course) and paid for by certain corporations. The sugar rush saga, where a bunch of exceedingly corrupt doctors proved sugar rush does not exist and corporate media spread it around and you can fucking guess who paid for it. The missing fact, that was in the research but not mentioned by entirely corrupt corporate main stream media, the sugar consumption was part of a properly balanced diet and never exceeded recommended calorie intake, nothing fucking what so ever like a bunch of children eating every sugary thing in sight at a party and then going nuts and collapsing sometime there in after. Done on purpose, with an air of impartiality but entirely cooked up from the get go, by professionals who should have been pilloried, tarred and feathered and driven out of the community, all paid for by junk food companies. Yep they do it, all the fucking time and this little story is just an example of their example, how one single fact left out on purpose can distort the entire outcome and done on purpose.

They should have refereed to the sugar rush fraud as a example of this kind of corruption of science.

Steroids don't cause muscle growth

[johnpagenola]

My favorite study along these lines was a randomized selection of men, half of whom were injected with steroids and half got no steroids. Neither group showed muscle gains during the study period. Not mentioned in the headline was that neither group lifted weights or engaged in any exercise. So in a sense the headline was true: just taking steroids doesn't give you big muscles. But the guys in my gym who took steroids got big because they were able to recuperate faster from heavier workouts.

Bullshit is bullshit.

[Gravis Zero]

For some reason, nobody has ever done a randomized controlled trial of parachutes.

It would be unethical to send people to their certain deaths when gravity has been sufficiently tested to the point where it is accepted as a physical constant.

However, I'm sure ethicists would be willing to look the other way if all idiots complaining about a lack of controlled trial were used as the subjects of such a test.

Re: Why are the most educated people dumb as brick

[jd]

Then you didn't understand it. Which, in all honesty, doesn't reflect on them.

Supplement studies are my favorite

[Okian Warrior]

My favorite study along these lines was a randomized selection of men, half of whom were injected with steroids and half got no steroids. Neither group showed muscle gains during the study period. Not mentioned in the headline was that neither group lifted weights or engaged in any exercise. So in a sense the headline was true: just taking steroids doesn't give you big muscles. But the guys in my gym who took steroids got big because they were able to recuperate faster from heavier workouts.

My favorites are medical studies on vitamins and supplements and other related.

For example, a 4-week study of Glucosamine/Chondroitin supplements that had no effect on joint pain of Rheumatoid Arthritis patients.

Conclusion? G/C supplementation has no effect.

Reality? We don't really know. 1) G/C supplementation is to make stronger and healthier joints by supplying building blocks not otherwise found in the diet, and 2) Joints have no blood vessels, so change very slowly. Typically 7 weeks or more would be needed to see an effect.

Compare with: St. John's Wort depression studies lasting less than 4 weeks (medical depression meds sometimes take as much as 6 weeks to show an effect), Omega 3 fatty acid supplementation studies in healthy adults (instead of children/adults with behavioral issues), and so on.

Nutrition studies are particularly useless. My favorite example is the guy making Soylent started out by asking the simplest question: what nutrients do we actually need to be healthy?

The answer is: No one knows, the literature is a bewildering mess of confusing and contradictory results, and nutrition experts have differing views.

(If you don't believe me, see if you can determine a) the *minimum* amount of vitamin D needed daily to prevent disease, and b) the *optimum* amount needed for best health. Bonus points if you can determine whether mega doses of Vitamin D are toxic. Supplemental bonus points if you can determine whether mega doses of Iodine are toxic.)

Their point was selecting patients

[raymorris]

Their point was that the results of my medical study very much depend on which patients are selected for the study.

Those who are likely to recover probably won't show much benefit from the treatment, because they were going to be okay anyway. Those who have a really bad prognosis may not show much benefit because they are past the point of no return, beyond help. In other studies, using patients who have a bad prognosis may exaggerate the benefits of the treatment by neglecting to include the fact that most people would be fine without the treatment. That is, the study might seem to indicate "the treatment doubles your chance of survival", but that's not true if the 90% of people with mild cases aren't included in the study.

Here, they used subjects with a very mild case of "jump out airplane". The study showed that parachutes provide no benefit - but only because the study participants had a very mild degree of the problem. One could also do a study of extreme cases and discover parachutes don't work for jumping out of an SR-71 at cruise. The study would need to include participants with varying "a priori" prognosis, and probably run stats for each class - good prognosis, bad prognosis, and in between.

Re:Asimove had this in a story...

[Greyfox]

120...ish. I fall closer to 130. I might be able to slow down to 120, but it takes some work on my part. The fastest speed on my digital altimeter is 205 mph, attained in a very steep dive at 9000 feet. I leveled into a track shortly after that, since opening a parachute at 205 mph would kill me just about as fast as not opening a parachute at 205 mph. Some of the kids I've seen flying in the wind tunnel fall at 70-80 mph. If you weigh less than 90 pounds and know how to fall slowly, I reckon you might be able to survive a terminal velocity fall if you land on the right surface. If you can find a surface that doesn't shatter some bones in the process, that'd actually be a fun party trick.