5 ms·

What is the _reason_ for ending it early? Is it the cost? I imagine it must be high enough because then they're gonna have to fight with this very criticism lat

by pen2l 6y ago

What is the _reason_ for ending it early? Is it the cost? I imagine it must be high enough because then they're gonna have to fight with this very criticism later on: RCT ended prematurely, therefore it is not as reliable. A question to you and grandparent post: what are the things that distinguish a high quality RCT from a poor one? The number of participants, the design study, etc.? Any links/resources that discuss this would be appreciated. edit: ok, I found a paper on this: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3429837/#:~:text=Randomized%20controlled%20trials%20(RCTs)%20have,of%20medical%20treatments%20(1) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3429837/#:~:tex.... I am super curious now about any discussion that reveals why the WHO study was less-than-stellar, and why the original RCT was considered high-quality.

shopwithpoints 6y ago
Its typically an ethical decision. In the event of a deadly disease ( cancer, covid, hiv etc ) its considered harmful to continue giving a less effective treatment once you have shown some superiority/inferiority.
arjunnarayan 6y ago
The reasoning is that as you gain information, you also have a duty to the people in the control group to use the best available information to take care of their health. Once you gain "enough" information ("enough" being statistically defined) that the drug helps, each additional person you let languish in the control group (who is denied access to the drug) is a cost that must be weighed against the benefit of getting additional information. When the data is clear enough, the cost can exceed the benefit, and you stop early. Typically you'd register a "stopping rule" before you start your trial: a good drug often will trigger the stopping rule, as it helped so much that we learned about its efficacy on a smaller N than originally planned. There are many different stopping criteria, depending on the trial (in safety trials you'd typically stop because you've found evidence that the drug is unsafe and continuing would be unfair to the folks in the treatment group, whereas in efficacy trials after safety has been established, you'd stop because you've found evidence that the drug is effective and continuing would be unfair to the folks in the control group).
- Siira 6y ago
  The reasoning is money, the unreasoning is ethical sophistry.
paulmd 6y ago
if you don't think the quality of the trial is so bad as to outright impair approval (and right now the political pressure for a tool, any tool, to fight COVID is so intense that there's zero chance it wouldn't be) then why continue? It costs money to do trials and it represents lost revenue where you could be the sole seller of the only known drug to treat a deadly pandemic. in fact there is a downside risk to continuing as well, further study might show that the early results were an outlier and the drug is not as effective as previously thought (or has some serious side effects in some situation), and then you lose all the money you've invested. But if you push it through, there is no risk of being sued since the US Government has waived any liability on the part of drug companies for these therapies. in a game-theoretic sense there is absolutely no benefit to continuing the trials and potential downsides to doing so. Remember, for-profit companies don't care about maximizing public health, they care about maximizing revenue. Especially when you've explicitly removed all financial liability for being risky with public health.
ffdjjjffjj 6y ago
It’s both ethical and statistical. If you observe a strong enough effect, you can reach significance with less data. When people are dying, sometimes you throw a Hail Mary.

by pen2l 6y ago

shopwithpoints 6y ago

Its typically an ethical decision. In the event of a deadly disease ( cancer, covid, hiv etc ) its considered harmful to continue giving a less effective treatment once you have shown some superiority/inferiority.

arjunnarayan 6y ago

The reasoning is that as you gain information, you also have a duty to the people in the control group to use the best available information to take care of their health. Once you gain "enough" information ("enough" being statistically defined) that the drug helps, each additional person you let languish in the control group (who is denied access to the drug) is a cost that must be weighed against the benefit of getting additional information. When the data is clear enough, the cost can exceed the benefit, and you stop early. Typically you'd register a "stopping rule" before you start your trial: a good drug often will trigger the stopping rule, as it helped so much that we learned about its efficacy on a smaller N than originally planned. There are many different stopping criteria, depending on the trial (in safety trials you'd typically stop because you've found evidence that the drug is unsafe and continuing would be unfair to the folks in the treatment group, whereas in efficacy trials after safety has been established, you'd stop because you've found evidence that the drug is effective and continuing would be unfair to the folks in the control group).

Siira 6y ago
The reasoning is money, the unreasoning is ethical sophistry.

paulmd 6y ago

if you don't think the quality of the trial is so bad as to outright impair approval (and right now the political pressure for a tool, any tool, to fight COVID is so intense that there's zero chance it wouldn't be) then why continue? It costs money to do trials and it represents lost revenue where you could be the sole seller of the only known drug to treat a deadly pandemic. in fact there is a downside risk to continuing as well, further study might show that the early results were an outlier and the drug is not as effective as previously thought (or has some serious side effects in some situation), and then you lose all the money you've invested. But if you push it through, there is no risk of being sued since the US Government has waived any liability on the part of drug companies for these therapies. in a game-theoretic sense there is absolutely no benefit to continuing the trials and potential downsides to doing so. Remember, for-profit companies don't care about maximizing public health, they care about maximizing revenue. Especially when you've explicitly removed all financial liability for being risky with public health.

ffdjjjffjj 6y ago

It’s both ethical and statistical. If you observe a strong enough effect, you can reach significance with less data. When people are dying, sometimes you throw a Hail Mary.