[jmckib]

I don’t have access to the full paper, but I would expect that they at least tried to control for sun exposure.

In general, if you can think of an obvious confounding factor in about five seconds, then it’s a safe assumption that professional researchers thought of it too.

[kixiQu]

Or, at least, a safer assumption: it's worth checking to see what they said about it before publicly speculating.

And indeed, it seems they did survey for sun exposure and include it in their analysis, and they caveat a lot of their references to other work in their introduction noting where other studies didn't.

https://www.naturalhealthresearch.org/wp-content/uploads/202...

[rcme]

Ok but they tried to control for sun exposure just by asking how much sun exposure have you gotten in your life? A little or a lot (paraphrasing)?

The issue with this is that the amount of vitamin D someone might take is correlated with how much sun exposure is available. And the amount of available sun exposure can impact what is considered a little / a lot to each person.

[KennyBlanken]

> Or, at least, a safer assumption: it's worth checking to see what they said about it before publicly speculating.

This would immediately kill about half of the comments on any research article posted to HN.

[dwighttk]

or publicly speculate and let a commenter who is more worried about checking check for you

[Calavar]

> In general, if you can think of an obvious confounding factor in about five seconds, then it’s a safe assumption that professional researchers thought of it too.

I work in academic medicine. I read a lot of papers. This is not at all a given in my experience, except maybe in the tippy top journals (Nature, NEJM). When in doubt, read the paper, see if they mention the confounder you thought of.

[oldgradstudent]

Not even NEJM:

Recent letter to the editor in NEJM about that paper that showed 90% drop in Covid-related mortality after the first booster:

https://www.nejm.org/doi/full/10.1056/NEJMc2306683

It turns out that there was also a similar non-disclosed drop in non-Covid-related mortality. Either we discovered a magic elixir, or the entire effect is probably just confounding.

The original authors even say in their response that

> However, boosters were generally not administered to hospitalized patients who were at high risk for death from any cause.

They never even attempted to control for it.

Edit: at least NEJM accepts letters to the editor about the crap it publishes.

[Iulioh]

>it’s a safe assumption that professional researchers thought of it too.

It's a safe assumption that they though of it

BUT

Testing for it and getting useful data of something like a survey is a different story.

For example for a thing like that a survey could do more harm than good if the principles aren't really strict.

It wouldn't surprise me that some researchers could have just ignored not measurable data like that for the analysis. (staring if ofc)

[Gimpei]

They probably have, but that doesn’t mean they have the necessary data to actually address the confounds. Often there is a trade off between what is most provable and what is most novel. Publishing incentives being what they are, novel invariably wins.

[mlinhares]

The study is based on a couple hundred people in a city in Finland, they could at least have tried to collect data on people closer to the tropics to hedge a bit. I doubt this has any validity ignoring such a basic confounding factor like living in a place that does have a lot of sun exposure.

[Spooky23]

Keep in mind that people from Finland are more likely to have skin that makes them particularly vulnerable to Melanoma.

A loved one is fighting this right now - if something simple like supplements, dietary practices or drug development could reduce the risk, it could potentially prevent alot of suffering. Even if it doesn’t work, perhaps it’s a line of inquiry with some value.

[surfpel]

> safe assumption that professional researchers thought of it too

Research should be able to stand up to scrutiny. The scientific process depends on it.

Given the ongoing reproducibility crisis and plethora of garbage research coming out of academia, I’m not assuming anything about any research I see.

[andreareina]

Accounting for confounders is hard. Otherwise randomised controlled studies wouldn't be needed, and we'd not have taken this long to walk back the consensus that red meat causes cancer.