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

At some point we (researchers & scientists) should draw the line between correlation & causation.

That there is 40% less incidence in flu vaccinated patients is established by observation, but is it due to flu vaccine by itself or factors which surrounds itself in people more prone to flu or who are medically more conscious? (edit: think of analysis of variance tests among identifiable medical & socioeconomic variables). If the researchers establish a positive link, wouldn't it be worthwhile to then suppose that amyloid plaques are somehow related to viral influenza replication - which by itself sounds a bit absurd (edit: Ok lot of good reference about infections around AD. I take this back, my bad)

The alternative hypothesis is worth thinking too: Are people more prone to Alzheimer's also more prone to catching flu.

> wouldn't it be worthwhile to then suppose that amyloid plaques are somehow related to viral influenza replication - which by itself sounds a bit absurd

This is a prominent theory for the cause of Alzheimer's disease [1].

[1] https://news.ycombinator.com/item?id=31900354

At some point we (commenters on hacker news) should stop reflexively typing this in response to every study without reading the paper.

From the abstract:

> Propensity-score matching (PSM) was used to create flu-vaccinated and flu-unvaccinated cohorts with similar baseline demographics, medication usage, and comorbidities.

If you want to argue that the authors did a bad job at this, for some reason, that would be a really meaningful contribution and I'd love to hear the details.

Otherwise, can we assume that the scientists writing and reviewing papers did a semi-competent job and are at least as good at analyzing quantitative claims as someone commenting on HN because they are bored at work?

I am not an expert at this, though I have taken few credits of Biostatistics. I would be more interested if swapping the variables also gave significance in tests. Did the Alzheimer's cohort also have a higher incidence of flu related comorbidities? I understand this is difficult - but this is why ANOVA tests also are extensively used to show variable dependence or report the degree of dependence. It is unclear from their findings. Without that we are probably looking at some positive correlation without investigating the causation.

But virtual HN karma points are so juicy! /s

Sometimes HN can do this or turn simple topics into some crazy meta stuff… I’m telling you so many times some comments look like what I will find in a parody of HN and/or bring no real value to the discussion but are so articulated and counter arguing and expanding and what not. Heck half of the times those comments start a new paragraph mid comment with « Heck… ». And they all look the same. /renting

Hey, I can add all the references so noone else has to:

- http://www.tylervigen.com/spurious-correlations

- https://xkcd.com/882/

- (honorable mention: https://xkcd.com/552/ - gets cited less often but is relevant nonetheless)

Maybe you should look into specifics of what exactly I am asking as the question, before terming it "crazy meta stuff". I am trying asking valid questions, which may be wrong or someone will explain it better clearing my misconception. I will learn something new & be grateful. Win-win

What is your contribution by this rant exactly, except making yourself look absurd?

I was just renting and being sarcastic. I was talking in general about how HM comments can be. When I wrote the crazy meta stuff it was not about your comment. I agree that it is great to ask questions and learn. So if I hurt you in any way I’m sorry.