Nick Mark MD Profile picture
Mar 3, 2022 9 tweets 5 min read Read on X
New embarrassingly bad study of ivermectin is a textbook example of “confounding by indication”

In short a retroactive database review found that people w/ COVID did worse if given remdesivir (only given to sick inpatients) than ivermectin (only given to well outpatients)🤔
1/
There are many problems with this “study”.

First it’s generous to even call it a “study.” It’s an *abstract* of a retrospective database review. The whole “article” is less than a page (see below).

It wasn’t pre-registered.

sciencedirect.com/science/articl…
2/
The methods are weird.

They found 1.7 million people w/ COVID. Out of this group they identified 1,072 who received ivermectin (not exactly widely used) & 40k who received remdesivir

The groups were very dissimilar: IVM was 10 yrs younger. They don’t report any comorbidities
3/
Despite the groups being wildly dissimilar, they *somehow* adjusted for potential compounders. (They don’t say how)

Crucially they did NOT adjust for hospitalization status. This means they compared COVID outpatients (on IVM) to COVID inpatients (on remdesivir). 🍎to🍊

4/
The authors are interesting…

The first two are medical students, the 3rd is a plastic surgery resident.
(Nothing wrong with this, though it is weird for the MS not to be affiliated w/ SOM)

The fifth & sixth authors are plastic surgeons. Neither has expertise in ID or COVID
5/
The 4th author @JoseGonzalesZa1 is the head of the ID fellowship at UMiami. He is an actual expert on this topic.

Based on his other work, I’m pretty sure he doesn’t think ivermectin is an effective therapy as this abstract concludes. See translation of one of his articles👇
6/
All of this makes me wonder - did the authors all even read/approve this abstract?

Did the peer reviewers think it was odd that plastic surgeons were doing research on ivermectin for COVID?
7/
I wonder if this abstract was the work of an eager group of students/residents who were inadequately supervised by more experienced researchers

That seems like the only way to explain such an obvious confounder being missed

This must have slipped past peer review at #IMED21
8/
Bottom line:
-this abstract of a retrospective review is fatally flawed due to the confounder of hospitalization (+more). There is no evidence that ivermectin reduces mortality
-it won’t stop fringe docs cashing in on selling ivermectin from promoting this “massive study”
9/9

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More from @nickmmark

Feb 14
Musk is so stupid. Exhibit #10544

There aren’t thousands of 150 year olds getting paid social security. There are null values in a database he doesn’t understand how to read… Image
When unidentified people get admitted to the hospital the default DOB is 1/1/1900. The EHR shows their age as 125 yo.

But *almost* everyone is smart enough to understand this is just a result of missing data… Image
Nice summary here debunking Elon’s “duplicate SSNs” claim.

thedatageneralist.com/elon-musk-does…
Read 4 tweets
Feb 8
Important point re indirects:

Unlike other Trump moves, this is arguably GOOD news for researchers!

If the NIH budget is unchanged (a big if), this allocates more money to researchers; if you go from an indirect of 75% to 15% it means you can fund 3 grants instead of 2.
Some context:

Between 1947 and 1965, indirect rates ranged from 8% to 25% of total direct costs. In 1965, Congress removed most caps. Since then indirects have steadily risen.

2/
A lot of indirects go to thing like depreciation of facilities not paying salaries of support staff.

This accounting can be a little misleading.

If donors build a new $400m building, the institution can depreciate it & “lose” $20m/year over 20 years. Indirects pay this.

3/
Read 4 tweets
Jan 22
🚨Apparently all NIH Study Sections have been suspended indefinitely.

For those who don’t know, this means there won’t be any review of grants submitted to NIH

Depending on how long this goes on for, this could lead to an interruption in billions in research funding.
With a budget of ~$47.4B, the NIH is by far the biggest supporter of biomedical research worldwide.

Grants are reviewed periodically by committees of experts outside of the NIH.

When these study sections are cancelled, it prevents grants from being reviewed & funded.
Hopefully this interruption will be brief (days)

A longer interruption in study sections (months) will inevitably cause an interruption in grant funding. This means labs shutdown, researchers furloughed/fired, & clinical trials suspended. This will harm progress & patients!
Read 8 tweets
Oct 13, 2024
#HurricaneHelene damaged the factory responsible for manufacturing over 60% of all IV fluids used in the US, leading to a major national shortage.

As clinicians what can we do to about the #IVFluidShortage and how can we prevent this crisis from happening again?

A thread 🧵
1/ Image
There are many things we can do as clinicians to improve ICU care & reduce IVF use.

1️⃣Don't order Maintenance IV Fluid!
Almost no patient actually needs continuous IV fluids.
Most either need resuscitation (e.g. boluses) or can take fluid other ways (PO, feeding tube, TPN).
2/
Frequently if someone is NPO overnight for a procedure, MIVF are ordered.
This is wrong for two reasons.
We are all NPO while asleep & don't need salt water infusions!
We should be letting people drink clears up to TWO HOURS before surgery, per ASA.

3/ pubs.asahq.org/anesthesiology…Image
Read 16 tweets
Oct 1, 2024
New favorite physiology paper: Central Venous Pressure in Space.

So much space & cardio physiology to unpack here including:
- effects of posture, 3g shuttle launch, & microgravity on CVP
- change in the relationship between filling pressure (CVP) & LV size
- Guyton curves!
1/

Image
Image
Image
To measure CVP in space they needed two things:
📼 an instrument/recorder that could accurately measure pressure despite g-force, vibration, & changes in pressure. They built & tested one!
🧑‍🚀👩‍🚀👨‍🚀 an astronaut willing to fly into space with a central line! 3 volunteered!
2/
Image
Image
The night before launch they placed a 4Fr central line in the median cubital vein & advanced under fluoro.

🚀The astronauts wore the data recorder under their flight suit during launch.

🌍The collected data from launch up to 48 hrs in orbit.
3/
Image
Image
Read 16 tweets
Jul 16, 2024
The media silence on this is deafening.

Did he have a head CT? What did it show?
Did he have stitches? Tetanus shot?

The NYT ran nonstop stories about Biden’s health after the debate but can’t be bothered to report on the health of someone who was literally shot in the head?
To the people in the replies who say it’s impossible because of “HIPPA”
1. I assume you mean HIPAA
2. A normal presidential candidate would allow his doctors to release the info. This is exactly what happened when Reagan survived an assassination attempt.
washingtonpost.com/obituaries/202…
My advice to journalists is to lookup tangential gunshot wounds (TGSW).

Ask questions like:
- what imaging has he had?
- what cognitive assessments?
- has he seen a neurosurgeon or neurologist?
- he’s previously had symptoms like slurred speech, abnormal gait - are these worse?
Read 4 tweets

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