4 ms·

He means that most of the placebo is covered by a statistical effect, regression to the mean, etc. https://sciencebasedmedicine.org/the-placebo-myth/ https://s

He means that most of the placebo is covered by a statistical effect, regression to the mean, etc. https://sciencebasedmedicine.org/the-placebo-myth/ https://sciencebasedmedicine.org/the-placebo-myth/

btilly 8y ago
That may be most of the effect on the group taking the placebo. But it is not the placebo effect. Were there no placebo effect, then we could test the effectiveness of drugs by simply observing one group and giving the other our proposed treatment.
- logifail 8y ago
  There are drug candidates that make it all the way to phase 3 trials before they fail. One of the (surprisingly?) common reasons for failure at this stage is turning out to be less effective than placebo https://www.nuventra.com/resources/blog/placebo-response-phase-3-failures/ https://www.nuventra.com/resources/blog/placebo-response-pha... https://seekingalpha.com/article/256697-why-phase-3-trials-fail-what-investors-need-to-know https://seekingalpha.com/article/256697-why-phase-3-trials-f...
  - btilly 8y ago
    Reading the articles left me with the impression not that they were less effective, but that they couldn't prove efficacy. So they could win, or lose, but it was close. It is also worth noting that one of the reasons why this happens in stage 3 despite having passed through a test in stage 2 that was meant to whittle this out is that improved expectations increase the strength of the placebo effect. Which makes the real effect harder to detect.
    - logifail 8y ago
      > not that they were less effective, but that they couldn't prove efficacy Could you explain the difference?
      - btilly 8y ago
        To prove efficacy, you have to have a statistically significant win. If you're ahead by a small margin, it isn't evidence that you're less effective. But you did not prove efficacy.
logifail 8y ago
> "Aint no such thing as a placebo effect, only a change in perception" I find that statement disingenuous. Is the author really claiming that "a change in perception" isn't real?

btilly 8y ago

That may be most of the effect on the group taking the placebo. But it is not the placebo effect. Were there no placebo effect, then we could test the effectiveness of drugs by simply observing one group and giving the other our proposed treatment.

logifail 8y ago
There are drug candidates that make it all the way to phase 3 trials before they fail. One of the (surprisingly?) common reasons for failure at this stage is turning out to be less effective than placebo https://www.nuventra.com/resources/blog/placebo-response-phase-3-failures/ https://www.nuventra.com/resources/blog/placebo-response-pha... https://seekingalpha.com/article/256697-why-phase-3-trials-fail-what-investors-need-to-know https://seekingalpha.com/article/256697-why-phase-3-trials-f...
- btilly 8y ago
  Reading the articles left me with the impression not that they were less effective, but that they couldn't prove efficacy. So they could win, or lose, but it was close. It is also worth noting that one of the reasons why this happens in stage 3 despite having passed through a test in stage 2 that was meant to whittle this out is that improved expectations increase the strength of the placebo effect. Which makes the real effect harder to detect.
  - logifail 8y ago
    > not that they were less effective, but that they couldn't prove efficacy Could you explain the difference?
    - btilly 8y ago
      To prove efficacy, you have to have a statistically significant win. If you're ahead by a small margin, it isn't evidence that you're less effective. But you did not prove efficacy.

logifail 8y ago

> "Aint no such thing as a placebo effect, only a change in perception" I find that statement disingenuous. Is the author really claiming that "a change in perception" isn't real?