
Apollo astronauts dying of heart disease at 4-5X the rate of counterparts - shawndumas
http://arstechnica.com/science/2016/07/apollo-astronauts-dying-of-heart-disease-at-4-5x-the-rate-of-counterparts/
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nkurz
At a quick read, the study this article is based on seems like it's either a
parody, a pointed critique of abusive statistical methods, or a terrible
misunderstanding.

On the bright side, the paper seems clearly written and is freely
available[1]. On the not-so-bright side, they conclusion of the study is based
on the a sample of 7 lunar astronauts, of whom 3 died of cardiovascular
disease. 3/7 is 43%. Surely they can't be claiming to have a statistically
significant result based on the having 3 rather than 2 lunar astronauts?

Yup, that's exactly what they are claiming. 3 of the 35 non-flight astronauts
died of heart disease, which is 8.5%.[2] Since there were 5 times as many in
this group as the lunar-flight group, that's the upper multiple of 5X. For the
low-earth-orbit-only group, 4 out of 35 (coincidental same number) died of
heart disease. 4/35 is 11%, which gives us the lower 4x.

Maybe as so often happens, the author of the Ars Technica article putting more
weight on this minor detail than the authors, while simultaneously removing
the carefully phrased caveats? Given that the title of the article is "Apollo
Lunar Astronauts Show Higher Cardiovascular Disease Mortality: Possible Deep
Space Radiation Effects on the Vascular Endothelium", I think we can eliminate
this excuse.

I'm hope I'm being too harsh.[3] Perhaps someone with a better grounding in
statistics than me can defend their methods and show me what I've missed?

[1]
[http://www.nature.com/articles/srep29901](http://www.nature.com/articles/srep29901)

[2]
[http://www.nature.com/articles/srep29901/tables/2](http://www.nature.com/articles/srep29901/tables/2)

[3] How did this get published in Nature? How can this possibly have passed
statistical review? Wait, you mean "peer review" doesn't imply "statistical
review"? Well then why should we trust their peers to vouch for the statistics
any more than we trust the authors?

~~~
bbctol
The main goal of the paper was to explore a possible mechanism for the finding
in a mouse model. The differences between Apollo and non-Apollo incidences of
heart disease are ~technically~ significant, but look to be there more as
motivation for the experiment than a conclusion in their own right--their
analysis of astronauts in general vs. the rest of the US population is also
new, and more interesting.

