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Lesson of ivermectin: meta-analyses based on summary data alone are unreliable

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Re: Lesson of ivermectin: meta-analyses based on summary data alone are unreliable

#221

Post by nradov »

mlyle wrote: post #189
sjwalter wrote: post #56

Earlier quoted context omitted.

Calling the investigatory and experiential evidence of thousands of highly-trained doctors (some of whom pioneered the standard of care for covid) as "weak evidence" is something that only somebody carrying water for large pharmaceutical companies would say. Doctors in my area are prescribing IVM to treat covid because in their experience and that of their peers IT WORKS. They have fewer deaths, fewer complications.…

> Calling the investigatory and experiential evidence of thousands of highly-trained doctors (some of whom pioneered the standard of care for covid) as "weak evidence" is something that only somebody carrying water for large pharmaceutical companies would say. Keep in mind that bleeding with leeches was once the standard of care-- based on clinical intuition and observational evidence. People-- even very smart, well-…

The RCT is the gold standard, but observational studies can be sufficient to establish causality when the effect size is large enough with a clear dose response curve. No one has ever conducted an RCT to prove that cigarette smoking causes lung cancer, but we're pretty sure that it does.

Re: Lesson of ivermectin: meta-analyses based on summary data alone are unreliable

#222

Post by marcosdumay »

mechE321 wrote: post #71

The Bayesian gambler in me wants to think this: The studies on ivermectin seem to be split between "good effect" and "no effect," and there don't seem to be any (by my extremely informal review! going off of memory here) in the camp of "bad effect." Seems reasonable to take ivermectin as a decent gamble to me while we wait on the dang science to get its head out of its butt.

Ethical researchers will prematurely stop and publish a "no effect" result for any medicine that has bad effects. That is, unless the effects are so bad that they can't stop fast enough, and they get to measure a statistically relevant harm.

Thus seeing "no effect" places an upper bound on how good an effect you will see as "none", and a lower bound as "won't kill most people quickly". That's not a good space to gamble into.

It took almost an year until the scientific community settled down that HQC for treating COVID-19 is harmful. The actual formal result is still "no effect and doing more studies is anti-ethical" because nobody can tell exactly how harmful it is. Probably nobody will ever be able to tell (and that's a good thing).

Re: Lesson of ivermectin: meta-analyses based on summary data alone are unreliable

#223

Post by antman »

nradov wrote: post #210
tantalor wrote: post #82

Earlier quoted context omitted.

FiveThirtyEight weights its averages by pollster accuracy/methodology. Next, we determine how much weight to give each poll in our average. First, polls conducted by pollsters with higher FiveThirtyEight pollster ratings — a letter grade measuring how accurate and methodologically sound pollsters are — are given more weight https://fivethirtyeight.com/features/how-were-tracking-joe-b...

There is no equivalent feedback mechanism in medical research. Other than looking for retracted papers, we don't have a reliable way to quantify whether a particular author is "correct" more often than another.

The author’s Hindex could be an initial weighting factor

Re: Lesson of ivermectin: meta-analyses based on summary data alone are unreliable

#224

Post by cyounkins »

There is a lot of confusion on whether there actually was a significant increase in calls to poison control centers due to ingestion of ivermectin.

This [1] official Mississippi government document says, "At least 70% of the recent calls have been related to ingestion of livestock or animal formulations of ivermectin purchased at livestock supply centers."

But then the AP [2] seemed to say that was incorrect: "The Associated Press erroneously reported based on information provided by the Mississippi Department of Health that 70% of recent calls to the Mississippi Poison Control Center were from people who had ingested ivermectin to try to treat COVID-19. State Epidemiologist Dr. Paul Byers said Wednesday the number of calls to poison control about ivermectin was about 2%. He said of the calls that were about ivermectin, 70% were by people who had ingested the veterinary version of the medicine."

Does anyone have additional clarification?

[1] https://msdh.ms.gov/msdhsite/_static/resources/15400.pdf

[2] https://www.sfgate.com/news/amp/Health-Dept-Stop-taking-live...

Re: Lesson of ivermectin: meta-analyses based on summary data alone are unreliable

#225

Post by jacquesm »

ashtonkem wrote: post #26

The other takeaway is that preprint publication is a pathway ripe for abuse. The major paper that drove most of this situation, and the meta analysis, appears to have been a straight up fraud. But it got circulated a lot as a preprint to people who didn’t understand the difference between a preprint and a peer reviewed paper. If the preprint had been more private, this might have been averted.

That wasn't an accident.

Re: Lesson of ivermectin: meta-analyses based on summary data alone are unreliable

#226

Post by jacquesm »

sjwalter wrote: post #56
mlyle wrote: post #49

Earlier quoted context omitted.

> The vast majority of the studies about Ivermectin have been observational, run by front-line clinicians. OK, so weak evidence. > Prior to 2020, basically everyone on earth agreed (including the WHO, who STILL agrees) that front-line clinicians and observational studies are excellent signals that can lead to scientific investigations that can lead to medical breakthroughs. Sure-- weak/crappy evidence and practitione…

Calling the investigatory and experiential evidence of thousands of highly-trained doctors (some of whom pioneered the standard of care for covid) as "weak evidence" is something that only somebody carrying water for large pharmaceutical companies would say. Doctors in my area are prescribing IVM to treat covid because in their experience and that of their peers IT WORKS. They have fewer deaths, fewer complications.…

> is something that only somebody carrying water for large pharmaceutical companies would say

This is directly against the HN guidelines.

Re: Lesson of ivermectin: meta-analyses based on summary data alone are unreliable

#227

Post by ABeeSea »

angelzen wrote: post #196
PaulDavisThe1st wrote: post #146

Earlier quoted context omitted.

They're [often] using the horse formulation because their doctor said no .

This is such a hypothetical. How many people got ivermectin against their doctor prescription, and how many got adverse effects from that? 1 in 100M?

Farm supply stores are out of stock from idiots buying livestock formation. Some are now requiring proof of horse ownership to buy it.

https://www.google.com/amp/s/news.yahoo.com/amphtml/vegas-st...

Re: Lesson of ivermectin: meta-analyses based on summary data alone are unreliable

#228

Post by rscho »

derbOac wrote: post #129
gwerbret wrote: post #44

I'm going to make what is probably a controversial statement, which is that, in my experience, most meta-analyses are trash. A meta-analysis is usually grounded on the assumption that an aggregation of multiple, well-conducted studies can provide significant information that may not be evident by taking each study individually. Essential to this assumption is the premise that those studies included in the meta-analys…

So I'm someone who has published several meta-analyses of different forms, and written about meta-analysis as a topic. I won't disagree with you that there are many poorly conducted meta-analyses. However, I think there's many well-done meta-analyses as well, and most importantly maybe meta-analyses aren't really different from anything else in life: some are good, some are bad, and many are in between. One thing I'v…

Even meta-analysis conducted strictly according to PRISMA can be fraught with many issues. IMO, meta analysis is very vulnerable to bias in the base data and the honesty of multiple researchers, all while p-hacking and various other tricks to make papers sexier are already the norm. Forcing open data would certainly improve things but would not solve the problem of dishonesty in research, since authors would simply begin to withhold parts of their data that do not go their way.

Re: Lesson of ivermectin: meta-analyses based on summary data alone are unreliable

#229

Post by ashtonkem »

cableshaft wrote: post #111
vernie wrote: post #84

Earlier quoted context omitted.

Is that really the reason or is it that they can't get a doctor to write them an off-label prescription?

A friend of mine found a doctor to prescribe it but his pharmacy won't fill it. He is so pissed. He was only planning to take small doses here or there as he's a teacher and around sick kids all the time, as if it were like Zinc to hopefully help reduce the severity of Covid-19 if he does get it, but despite going through the effort and succeeding in finding a doctor willing to prescribe it (and my friend even signed…

> pharmacy shouldn't be allowed to decide not to fill it, as if they know better than your doctor.

It sounds like you have a pretty misguided idea of how pharmacies and pharmacists worked before Covid. You’re describing a situation where pharmacists act at the behest of doctors who know best, when in reality pharmacists have always had some level of independent authority over what drugs get dispensed to whom thanks to their expertise. It’s part of the pharmacists job to watch out for bad prescriptions, both in terms of abuse (e.g. opioids) improper dosages, and unintended side effects and interactions between drugs. In some states pharmacists have their own ability to prescribe medicine on their own.

I’m not sure exactly how much control a pharmacist should have over whether a valid prescription is filled, but the idea that they’re only expected to blindly fulfill the order of your doctor is not correct, and never was. In fact, they probably know more about the drugs you’re prescribed than your doctor does, as that’s their entire speciality. (Especially given the long and sordid history of doctors pushing drugs on the basis of pharmaceutical sales reps, doctors often actually know very little about what they prescribe).

Re: Lesson of ivermectin: meta-analyses based on summary data alone are unreliable

#230

Post by aantix »

ashtonkem wrote: post #30
rory wrote: post #25

Ivermectin probably doesn't do anything to fight Covid-19, but the American media has really shown their corruption in the way they've treated it. It's clearly a safe drug to take in human-designed doses, and it's cheap to produce. Laughing at people for poisoning themselves with "horse dewormer" instead of pointing out that they are turning to the vet store because their access to medicine has been marginalized is s…

People are literally taking horse formulations of ivermectin because doctors are rightfully refusing to prescribe ivermectin for an off label and ineffective use. Oh, and the access to this medicine is “marginalized” BECAUSE IT DOESNT WORK TO TREAT COVID. We generally do not expect doctors to prescribe medicine that will not work or is not appropriate for the patients condition. Complaining about their access being m…

What am I missing?

https://ivmmeta.com/#rct

Evaluation of Ivermectin as a Potential Treatment for Mild to Moderate COVID-19: A Double-BlindRandomized Placebo Controlled Trial in Eastern India

https://journals.library.ualberta.ca/jpps/index.php/JPPS/art...

Ivermectin in combination with doxycycline for treating COVID-19 symptoms: a randomized trial

https://journals.sagepub.com/doi/pdf/10.1177/030006052110135...

Ivermectin shows clinical benefits in mild to moderate COVID19: a randomized controlled double-blind, dose-response study in Lagos

https://academic.oup.com/qjmed/advance-article/doi/10.1093/q...

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