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Flu vaccination linked to 40% reduced risk of Alzheimer’s disease

uth.edu

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Re: Flu vaccination linked to 40% reduced risk of Alzheimer’s disease

#111

Post by ncmncm »

bloodyplonker22 wrote: post #80
yeeetz wrote: post #24

Earlier quoted context omitted.

This is a published journal article that took those covariates into account. Off-hand comments dismissing articles with a correlation vs. causation quip is so expected and tiresome, especially since you can make these comments without reading the actual article.

It's interesting how you can condescendingly say "took these covariates into account" without even thinking about how many outside variables there are that they simply cannot take into account because there are obviously too many. Most people don't think too much and just read articles and take anything in writing as the truth.

"Most people", particularly, who make knee-jerk "correl- not causation" trolls for HN points.

You played yourself.

Re: Flu vaccination linked to 40% reduced risk of Alzheimer’s disease

#112

Post by ncmncm »

zugi wrote: post #108
sudosysgen wrote: post #70

Earlier quoted context omitted.

Correlations do imply a link, though. They don't imply causation, but in the absence of selection bias and with enough of a sample size, it is almost certain there is a link somewhere.

Indeed there is a link but we don't even know the direction of causation. I find it quite plausible that people with as-yet undiagnosed early-onset Alzheimer's forget to get flu shots.

Yet, you also find it plausible that people who spent years on this project would never have thought of that.

Your misplaced trust in your own plausibility filter causes you to make foolish posts on HN.

Re: Flu vaccination linked to 40% reduced risk of Alzheimer’s disease

#113

Post by Jensson »

bink wrote: post #25
standardUser wrote: post #21

If anyone out there thinks there are still people who don't realize that "correlation does not equal causation", don't worry, we all know.

Now you just have to convince them that scientists know how to control for these effects.

Scientists are incentivised to not control for these effects, so often they don't. Especially in papers reaching the news since they are usually "ground breaking" because they abused statistics.

Re: Flu vaccination linked to 40% reduced risk of Alzheimer’s disease

#114

Post by Jensson »

Jedd wrote: post #92
DarkmSparks wrote: post #88

While this would be lovely, I think it just proves people with dementia are less likely to remember to get a flu vaccine.

> I think it just proves people with dementia are less likely to remember to get a flu vaccine. I think you may have misread the fine article. Symptoms were observed to develop (or not develop) after a flu vaccination shot.

Dementia is preceded by many years of cognitive decline, it isn't something that just appears. A person with partially developed dementia that wouldn't get detected in a screen is still probably less likely to go get a flu shot, wouldn't you think?

Re: Flu vaccination linked to 40% reduced risk of Alzheimer’s disease

#115

Post by ncmncm »

loeg wrote: post #109
ncmncm wrote: post #104

Earlier quoted context omitted.

Not just those. Tdap shows a 40% effect size, too. Better get your shingles and/or chicken pox, too.

Chicken pox and shingles are the same virus. If you've had chickenpox, they won't give you that vaccine. But you should definitely get the shingles vaccine either way, if possible (CDC is still denying it to adults under 50, even though shingles affects adults under 50).

Your facts are opposite to reality.

If you had chicken pox (even asymptomatic), that puts you at especial risk for shingles; not surprisingly, as it is a retrovirus.

I had chicken pox, and got the shingles vaccine. They did not ask.

Re: Flu vaccination linked to 40% reduced risk of Alzheimer’s disease

#116

Post by Jensson »

ac29 wrote: post #75
jeffreportmill1 wrote: post #51

Possible alternate title: "People with early onset Alzheimer's frequently forget to get flu shots".

Given that >90% of non-vaccinated patients did not get a Alzheimer's diagnosis, this seems wrong.

Why? You got many people who don't want to get a flu shot for other reasons. But if lets say Alzheimer's makes the people who normally gets it forget to go, then that would greatly skew how many with very early Alzheimer's gets flu shot, making it look like flu shots "protects" against Alzheimer's.

And no, checking whether they had it beforehand doesn't help, it starts to develop many years before its symptoms are so strong that you identify them as Alzheimer's, forgetting rare and optional appointments certainly wouldn't be enough to say it is Alzheimer's yet. That is why scoring well on an IQ test also "protects against Alzheimer", it isn't that the IQ test protects you, it is that the IQ test can detect effects of Alzheimer's before a diagnosis can see it.

Re: Flu vaccination linked to 40% reduced risk of Alzheimer’s disease

#117

Post by DarkmSparks »

Jensson wrote: post #114
Jedd wrote: post #92

Earlier quoted context omitted.

> I think it just proves people with dementia are less likely to remember to get a flu vaccine. I think you may have misread the fine article. Symptoms were observed to develop (or not develop) after a flu vaccination shot.

Dementia is preceded by many years of cognitive decline, it isn't something that just appears. A person with partially developed dementia that wouldn't get detected in a screen is still probably less likely to go get a flu shot, wouldn't you think?

exactly this, because there is no treatment diagnosis is delayed as long as possible to avoid the stigma, by the time people get a diagnosis they are generally at the point they forget when to feed themselves.

Prior to that the decline can be decades in the making. My gran obviously had dementia for 15 years before her diagnosis, by the time she was given it the only words she could say was "keep on keeping on"

Re: Flu vaccination linked to 40% reduced risk of Alzheimer’s disease

#118

Post by dsizzle »

blagie wrote: post #36
i_love_limes wrote: post #26

Epidemiologist in training here... There are quite a few comments in this thread already jumping on the 'correlation != causation' train. While that is true, I'd like to clarify a couple things: 1. The journal article didn't suggest it was causal. But such a correlation with such a large population warrants publication and further research into causation. 2. literally the first thing that any epidemiologist would con…

The scientists said it was causation. "We found that flu vaccination in older adults reduces the risk of developing Alzheimer’s disease for several years. The strength of this protective effect increased with the number of years that a person received an annual flu vaccine – in other words, the rate of developing Alzheimer’s was lowest among those who consistently received the flu vaccine every year" Yes, that's in a…

This comment (and often the "correlation != causation" discussion more generally) seems to equate "causation" with "proof of causation" (in a mathematical sense), which is a flawed criteria for science IMO. The causation part (not the mere association) is the substance, so it's appropriate to use causal language.

Of course any such explanation is provisional. I might think your comment is just to complain the provisional aspect isn't mentioned in the quote (I think it'd be tiresome to say that in every statement, and the public's understanding of science being provisional is underestimated), but you seem to think it's a problem that causal language is used at all?

While quote may have been offhand, look at what the actual paper says [1]: "[the study] design prevent[s] strong conclusions regarding causation." Note that it doesn't say it prevents any conclusions regarding causation.

By the way, it seems weird that you yourself have come to believe it's causal, while seemingly denying that this paper provides any basis. How did you come to that conclusion then?

[1] In the last paragraph: https://content.iospress.com/download/journal-of-alzheimers-...

Re: Flu vaccination linked to 40% reduced risk of Alzheimer’s disease

#119

Post by Fomite »

ncmncm wrote: post #102
Fomite wrote: post #82

Earlier quoted context omitted.

Whether or not that's an incredible effect size sort of depends. For infectious disease epidemiology, which regularly sees extremely strong effects because of the very short causal chain between an infection and an outcome, it's not all that extraordinary.

It is an effect size that commands legitimate and substantial attention. It indicts everyone still huddled around the amyloid lamppost.

Agreed. I've just also seen "That's a huge effect size" as a way to dismiss observational results as probably wrong, and so felt it should be noted that for things with infectious etiologies this is impressive but not particularly outlandish (vs. say environmental epidemiology, where an effect size of this magnitude would mean congressional hearings).

Re: Flu vaccination linked to 40% reduced risk of Alzheimer’s disease

#120

Post by thaumasiotes »

Symmetry wrote: post #73
thaumasiotes wrote: post #68

Earlier quoted context omitted.

Causation frequently removes correlations that would otherwise exist.

I don't think that's right? In theory you could have A and B that were naturally correlated and add a causal relationship between the two that exactly canceled that correlation but that would be infinity unlikely to happen by chance. In practice the only way that A and B can be correlated is that either A causes B, B causes A, or some C causes both A and B. Interestingly if both A and B cause C the C and A as well as…

> In theory you could have A and B that were naturally correlated and add a causal relationship between the two that exactly canceled that correlation but that would be infinit[el]y unlikely to happen by chance.

That hardly seems relevant, since we're talking about causal relationships and chance is the opposite of causation.

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