Comment by Wowfunhappy
3 years ago
> the upside for the company is that if it works, they get the evidence of efficacy.
They don't, though. They need a control group.
3 years ago
> the upside for the company is that if it works, they get the evidence of efficacy.
They don't, though. They need a control group.
> They don't [get evidence of efficacy], though. They need a control group.
This is false. Control groups, preferably in double-blind studies, are an essential part of best practices. However, the bar for what constitutes evidence is much lower than that.
Evidence is any fact that makes a relevant conclusion more or less likely. Evidence need not be conclusive in and of itself. Over time, the cumulative effects of less-strong evidence can form the basis for a reasonable inductive conclusion. Sorry to be trite, but as an example, a person can have evidence that their romantic partner loves them without the use of an identical twin.
Insisting on gold standard medical evidence before allowing someone to undergo life-saving treatment—when the preponderance of the evidence that does exist supports that treatment—is, to be blunt, the very definition of depraved heart murder. It demonstrates a wanton disregard toward human life in the face of the known likelihood that it will result in some number of deaths.
More broadly, however, it is an extremely poor policy, in that this meme both weakens society's critical thinking generally and—among those who see through the elitist charade—significantly weakens the respect of those scientists who make the claim.
> Control groups, preferably in double-blind studies, are an essential part of best practices.
I wouldn't go that far. I think that a paradigm built upon a broader evidence base -- e.g. with far more extensive postmarketing surveillance of drugs -- would be more ethical, of more benefit to society, and ultimately more effective.
Double-blinded studies can miss, can be confounded by placebo effects, can easily be confounded by crooked researchers, and are frequently just plain unethical from first principles. I don't think that they should be considered "essential."
I think all your criticisms of randomized controlled trials (apart from the ethical one) apply to your suggested approach, no?
RCTs are the gold standard for demonstrating efficacy precisely because of the controls. I agree that they're not going to give you enough info about potential side-effects - a thorough monitoring program is definitely necessary for that.
But without RCTs, showing that a drug works would be much harder. How would you weed out the snake oil?
4 replies →
The people who have already died to-date of your terminal illness aren't a good enough control group to tell that your cure works? This is the absurdity of frequentist statistics. If you can't tell the difference between recovering from the treatment and recovering by natural luck, then either the treatment is barely effective at all, or the doctor had no basis to tell you in the first place that you had a terminal illness.
That is correct, the people that have already died are unable to act as effective controls. To establish the medicine causes the disease to go away, you have to use something like a randomized trial. Otherwise, causation is not established. It’s a very difficult problem and a lot of smart people have try to come up with better systems.
With all due respect, why? This seems fallaciously wrong.
It is rather akin to saying that I can't tell whether seatbelts reduce car-crash fatalities simply by comparing collision fatalities from 1967 seatbelt-lacking car models with otherwise-identical 1968 seatbelt-equipped models; I would need to actually randomly and secretly sabotage a certain percentage of the seatbelts from 1968-model cars, while deliberately ignoring everything I know about prior fatality statistics. Even if every automobile collision without seatbelts was fatal, and every collision after seatbelts became mandatory was survived, even if nothing about the cars or driving conditions had changed, you're implying that it wouldn't provide any evidence of the efficacy of seatbelts, unless we conducted a new trial from scratch with a randomized control group as though we had no prior data?
What is the actual difference, in terms of causal evidence, between someone who died of the same disease before the study officially begins, and someone in the "control group" who dies after the study begins?
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People who already died are less effective controls than double-blind controls getting a placebo, but they're not ineffective.
Given a treatment with a large effect size like penicillin, a causal link will be very easy to establish even with a suboptimal control group.
If a disease at a certain well defined stage has a 100% fatality rate after 6 months, why would you need a double blind trial if some patients are still alive 1 year after taking your drug ?
The causality is pretty clear and while you might not claim that it double the life expectancy it would IMHO be immoral not to fast track the approval of that drug.
There is a standard of evidence above guesswork and below controlled trials, that is still useful: you accumulate enough survival rate data of whatever specific terminal condition you're hoping to treat, and compare it to the baseline untreated survival rate, which is already known.
Any statistically significant difference there can then incentivize a drug research company to invest in the (expensive) clinical controlled trial process.
It's strange that people here are actually saying it's better to waste perfectly good research opportunities and watch patients die, than to risk having anything less than perfect evidence of efficacy.
And that is why you shouldn't be able to ask for the experimental treatment... You should be able to ask to be part of a trial of the experimental treatment.
Remember that if 10 treatments are being tried at once, you can divide the pool of participants so that only a smallish percentage are part of the control group.
...I think that's basically how it works? If the company is running a trial, you can enroll in the trial. AFAIK being in a trial is free for participants.
Of course, there are any number of reasons someone may be rejected from the trial. If that happens, the company isn't going to just freely give them the drug anyway, because it wouldn't provide scientifically valid data. Also, no one would enroll in a trial (which carries the potential of getting the placebo) if they could get the treatment outside the trial.
The drug itself might be paid for, as well as tests under the scope of the study (which might be narrow), but services to administer the drug, and tests or treatment for effects not in the scope of the study, aren't always covered. Or, in the stupidest cases, approval gets bogged down by the drug company, patient, or administering clinic/practitioner trying to get the patient's insurance to cover whatever's not covered by the trial for so long that the patient no longer qualifies (or is dead) by the time insurance relents and agrees to pay.
I have no better words: that is evil.
Can you clarify why that is evil? Are you referring to the use of control groups or the division of the test group into several overlapping trial compounds?
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They don’t exactly need a control group if the chance of living N weeks is effectively zero. They would need it for something like living N weeks and living N+1 weeks, but any kind of change from an individual expected outcome would be useful signal for maybe more rigorous testing.
Not always. In some cases, like rabies, the control group is 100% rate of death.
It is not. There are known treatment protocols with a reasonable (25%-ish) survival rate. There is also strong evidence that some people simply develop antibodies for it, and survive it without a vaccination or any treatment at all. It is rare, but definitely possible.
I think it’s common practice to give life saving treatment to the control group after there is some measure of confidence that the drug works.
They can then apply to launch formal clinical trials with a control group. This initial evidence of efficacy is of-course anecdotal evidence with more traceability.