Hydroxychloroquine Probably Isn’t the Answer • Hacker News Board

Re: Hydroxychloroquine Probably Isn’t the Answer

#111

Post by cma » Tue, Apr 07, 2020, 4:28 AM UTC

cma wrote: post #110

jojo2000 wrote: post #108

Earlier quoted context omitted.

It's a narrow viewpoint to only see it through the lens of death percentage. Of course it is a game-changer. You eradicate the viral load after 6 days instead of 20+. Meaning : - reduced contagion (avoiding big peak of infections), no confinement needed, so the better for the economy - you avoid complications, meaning less load on hospital, so you can save a lot of people who would have died otherwise. - people get b…

> You eradicate the viral load after 6 days instead of 20+. Meaning There would be many less deaths if so.

Sorry, I misunderstood this, I thought the data was Marseille vs the rest of France based on the wording, not one hospital in Marseille vs others in Marseille.

Re: Hydroxychloroquine Probably Isn’t the Answer

#112

Post by Dylan16807 » Tue, Apr 07, 2020, 4:38 AM UTC

gus_massa wrote: post #106

Dylan16807 wrote: post #94

Earlier quoted context omitted.

Valid issues, but you can have all of those problems in a randomized controlled trial too. That's not a very compelling argument that the non-random poorly-controlled version is any worse in this hypothetical.

For example if the "usual" death rate is 90% and you select some group of patients for security reasons, like 18<=age<=60, perhaps the death rate is reduced to 80%. If the testing and control group is randomized, then if there is no effect of the drug you will get the same 80% in both groups. If the group is not randomized, you can't be sure that any of the selection criteria is the cause of the improvement.

You can look at the selection criteria and perform an analysis. If the data is clear enough, you can still pull a signal out of the noise. I assume that's the reason you took a 70/73 survival rate in the hypothetical I posed and reduced it to 20% in your version. And to be clear, in my version it's a general hospital and they give the treatment to everyone that has this diagnosis. There are no intentional selection criteria, it's mostly just who lives in the area.

Re: Hydroxychloroquine Probably Isn’t the Answer

#113

Post by Dylan16807 » Tue, Apr 07, 2020, 4:53 AM UTC

h_r wrote: post #107

Dylan16807 wrote: post #93

Earlier quoted context omitted.

> Again, this is the very thing that needs to be shown. You're simply repeating the same mistake. "This" being the idea that "compelling evidence" and "evidence from randomized controlled trials" are not the same thing? That has been shown. The cliche example is parachutes. We have compelling evidence that they save lives, even though nobody has ever done a proper trial. Experiments don't have to be perfect to provid…

I hardly know where to start with this. Parachutes are not a cliche example of anything other than engineered products that are the result of well understood principles of physics, knowledge which was hardly arrived at by magical intuition. And medicine lags far far behind in the maturity of the science (my understanding as a layman). And your final example of showing up in scientifically illiterate society wielding…

Parachutes are a device for saving lives.

We know they work. We have evidence of efficacy. But this evidence does not come from randomized controlled trials.

If it was a pill, the standards for evidence should not change.

Randomized controlled trials make things easier to prove. But they are not the only way to collect evidence of efficacy.

> And your final example of showing up in scientifically illiterate society wielding a miracle drug and declaring that they need no evidence of its efficacy, ignoring the fact that such evidence was all on you prior to arriving there?

No evidence?? That's the exact opposite of what I'm trying to say.

Your objections... okay, would a better thought experiment be an invention of a new antibiotic?

There is no existing proof of anything.

I go to the nearest town and give the pill to every single resident with gonorrhea, 50 of them, and a few days later only 48 of them have the disease any more.

They otherwise took no drugs they hadn't already been taking for months.

I didn't randomize at all, and I didn't set up a control group.

But it's statistically impossible for that to happen by chance.

Also, I and a team of respected researchers searched for confounding factors just as hard as someone performing a randomized controlled trial, and we could not find any.

Did I provide evidence of efficacy? If not, why not?

Re: Hydroxychloroquine Probably Isn’t the Answer

#114

Post by cjhopman » Thu, Apr 09, 2020, 2:06 AM UTC

pseudalopex wrote: post #99

cjhopman wrote: post #65

Earlier quoted context omitted.

A proprietary drug whose maker has said they will donate all 1.5 million doses that they currently have. That's more than they'll be able to produce over the next year (1 million) even after greatly increasing that production capacity.

The goal is more than 1 million treatment courses (10 million doses) by the end of this year. https://www.gilead.com/stories/articles/an-update-on-covid-1...

Ah, I had misread that.

That statement didn't clearly say whether they were going to donate those that they haven't produced yet. If they aren't donating that, this donation is like a ~10% discount (compared to the ~66% discount I had originally interpreted it in that case).

Re: Hydroxychloroquine Probably Isn’t the Answer

#115

Post by gus_massa » Thu, Apr 09, 2020, 12:29 PM UTC

Dylan16807 wrote: post #112

gus_massa wrote: post #106

Earlier quoted context omitted.

For example if the "usual" death rate is 90% and you select some group of patients for security reasons, like 18<=age<=60, perhaps the death rate is reduced to 80%. If the testing and control group is randomized, then if there is no effect of the drug you will get the same 80% in both groups. If the group is not randomized, you can't be sure that any of the selection criteria is the cause of the improvement.

You can look at the selection criteria and perform an analysis. If the data is clear enough, you can still pull a signal out of the noise. I assume that's the reason you took a 70/73 survival rate in the hypothetical I posed and reduced it to 20% in your version. And to be clear, in my version it's a general hospital and they give the treatment to everyone that has this diagnosis. There are no intentional selection c…

[Sorry for the late reply.]

> If the data is clear enough, you can still pull a signal out of the noise.

It is theoretically possible, but very difficult. Unless you use a lot of people in the trial, but then you must ensure that the measurements are done in a consistent way.

> in my version it's a general hospital and they give the treatment to everyone that has this diagnosis

Does it include pregnant women and babies with less than 1 year? Does it include people with more than 90 years? Does it include people that goes to the hospital in an ambulance because they are almost dying, like a hearth attack? Does it include someone that had one of the lungs removed and is under a chemotherapy treatment?

What about people that can't sign the form for the experimental treatment? Just signing a form is a selection of people that is not toooooooooooooooooooo bad.

What about asymptomatic people? Does your are has the same policy to test everyone/someone/noone than the region you are comparing with? What about the effects of temperature or humidity?

What about diet? Poor people may have a bad diet, with a low amount of vitamins and that can affect the illness. Some countries drink a lot of milk and some very few, some countries add vitamins to the milk.

What about the median income? If the city has a few hospitals, there will be one closer to the poor area and other closer to the rich one. Some people has health plan that include one hospital(s) but not other hospital(s). How does it affect the selection of people in the hospital? Different countries have a different definition of poor.

Some hospital are famous and get more of the strange/difficult cases after the standard hospitals give up or realize it is a complex case.

I may be missing other factor, or overestimating some of them, but it is very difficult to be sure that you know all the things that change the cure rate and that you can correct the result.