Lots of people have been asking me to take a look at this observational ivermectin trial from Argentina, and I thought it'd be a nice change from all the fraud so here's a bit of a thread 1/n
2/n The trial is here, and it is a fairly simple epidemiological trial comparing people who were given ivermectin with those who weren't on ICU admission/death using large-scale registries in Argentina
zenodo.org/record/5525362…
3/n I've done a brief check for fraud, and the study looks fine. Honestly, I have no real issues with this paper as is, it's just not very useful as evidence for ivermectin

Let's think about why that is
4/n In observational trials, we have groups of people who have, for whatever reason, been grouped into categories. In this case, doctors and patients decided whether they should use ivermectin or not
5/n This creates an inherent bias in the dataset - there are obviously going to be differences between people who are offered/decide to take ivermectin and those who don't
6/n And in this case, we KNOW the two groups were very different because the authors demonstrated that they were

This is what's commonly called confounding, and you can adjust (control) for it
7/n The problem here is that we can control for variables that we collect - the authors have a model with age, sex, and a couple of comorbidities - but we can't control for stuff that we don't measure

This is called RESIDUAL confounding
8/n One very common issue with studies looking at medicine prescriptions is that people who get more meds are often richer, drink less, and eat better than people who don't get the meds
9/n Unfortunately, due to limitations in the data collection, the authors did not have enough information to control for these factors, or any of dozens of other issues that might cause people to be less likely to die
10/n What this means is that it's hard to interpret the results. People who got ivermectin died less, but they might have been richer, or had less severe COVID-19, than people who didn't get ivermectin

We just don't know!
11/n This is why it's important to run randomized clinical trials - observational research is amazing for lots of things, but when it comes to measuring the impact of a drug it has some very significant limitations
12/n Unfortunately, those limitations have nothing to do with sample size. It makes no difference if you've got 10 or 10,000 people, if you can't control for biases your estimates will be just as problematic
13/n (And I say that as someone with datasets that number in the millions with exactly the same issues that this research has. It's not an easy problem to solve!)
14/n Anyway, none of this is the fault of the authors, who ran a simple epidemiological study. It's fine as far as observational research goes, it just doesn't change the evidence-base much if at all

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More from @GidMK

4 Oct
For those interested in facts, there are two more fraudulent ivermectin trials with news dropping this week, at least two more with very high probability of fraud soon to come
It's also worth noting that when I talk about fraud, I'm only considering clinical and observational trials. Most of the ecological trials are so woeful that it doesn't really matter if anyone faked them, and I don't really assess basic science
Anyway, if you want to know exactly how many studies are flawed, we'll hopefully have it all up this week. Takes time to assemble this stuff working unpaid in our free time!
Read 5 tweets
2 Oct
Our big new study on the infection fatality rate of COVID-19 in developing countries is out

The news is pretty grim 🧵

medrxiv.org/content/10.110…
Throughout the pandemic, there has been an apparent contradiction - low-income places appear to have lower death rates from COVID-19 than higher-income areas

This makes no sense on the face of it
So, we looked at the infection fatality rate (IFR) of COVID-19 in every place that we could find, using antibodies to estimate the number of infections in each area and the number of registered deaths as our numerator
Read 15 tweets
25 Sep
Interesting paper. Seems to make it extremely unlikely that SARS-CoV-2 was created in a lab
It is amazing how many people mischaracterize "extremely likely" as "the only possible answer"

No, this does not mean that a lab leak is totally impossible
That being said, the appearance of very closely-related coronaviruses in non-lab settings obviously makes a natural origin quite likely, especially as there are no more closely related viruses in labs 🤷‍♂️
Read 4 tweets
23 Sep
I cannot believe the question was asked, and the response is even more absurd

No, the pandemic is not a "social construct" what utter garbage
Even the explanation of why the pandemic is "socially constructed" is total nonsense. That we may have had a different response without technology does not mean that what we are doing now is "constructed" in a philosophical sense
I mean, if the pandemic had happened 3 decades ago it's almost certain that the death toll would be FAR higher, so we might have actually had a MORE intensive regulatory response
Read 5 tweets
22 Sep
The ivermectin literature is full of fraud

What can we do about it?

Our new paper in @NatureMedicine argues that we need a systematic change to counter this issue

nature.com/articles/s4159…
The basic issue is that science works on trust. We assume that no one would ever fake a study, because it's ethically and morally indefensible, and work with that

Which makes it very easy for people to fake studies
However, people generally aren't very good at faking things. There are dozens of very simple checks you can run on data to see if it's real

Problem is, you need the data to do that
Read 5 tweets
21 Sep
It is demonstrably false to claim that intubation has led to more deaths during the COVID-19 pandemic, but this has not stopped Professor Ioannidis making the claim repeatedly

sciencebasedmedicine.org/intubations/
I also find the persistent myth that Prof Ioannidis promotes that death certification has lead to more Covid-19 deaths rather odd. I cannot find any basis for this in the literature he cites
For example, in this recent paper he makes the same claim and cites two papers. One is simply a guide to death certification, and not really an assessment of errors
Read 7 tweets

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