Hi Phil,
You are obviously right when you say that not all surgery needs to be
confirmed in effectiveness by double blind studies. No one would dream
of trying to confirm the effectiveness of a kidney transplant using a
double blind protocol. The example Johnson used however is the classic
example cited in its necessity. (From transcript of 20/20 ABCNEWS web
site)
DR TIMOTHY JOHNSON (on camera) The idea of
placebo surgery is not new, nor is the controversy
surrounding it. For example, back in the 1950s, doctors
tried fake surgery on patients with chest pain. Some
patients in the experiment got real surgery. Their chest
was opened up. An internal artery was tied off, then
they
were sewn back up. But other patients got fake surgery.
Their chest was opened up, but nothing was done inside.
Then they were sewn back up. But they were never told
they were in an experiment. They were never told they
got fake surgery. They were totally deceived.
Nonetheless, the results were amazing. (VO) Ted
Kaptchuk (ph) of Boston's Beth Israel/Deaconess
Hospital has studied the history of the placebo effect.
TED KAPTCHUK, BETH
ISRAEL/DEACONNESS HOSPITAL The people
that got the fake surgery, sham (ph) surgery, 100
percent
of them improved for six months on objective and
subjective measures. That's how long they followed
them. The people who got the real surgery, 72 percent
improved. That's an amazing example of the power of
surgery as a placebo.
DR TIMOTHY JOHNSON (VO) Placebo surgery
without patient knowledge raised obvious ethical
questions and was abandoned in the 1960s. But these
doctors from the University of Colorado and New
York’s Columbia Presbyterian Medical Center have
announced the results from a placebo brain surgery study
on Parkinson’s patients in which the patients were fully
informed.
If one ignores the the ethical breech (or better uses the experimental
design as a negative example), it is clear that one has to be quite
certain of "the obvious". It doesn't matter in the case of fetal
transplant (as a procedure in general use) what a PET scan shows if you
can't document clinical improvement that correlates with it. In my case
I have gotten clinically worse. I don't care (as a patient) what my PET
Scan shows. If others in my group have done as poor as I have then one
could not justify the risk of whatever surgery was done to me as a
treatment for PD (unless there was a placebo group which did considerably
worse). I do at some point want to know but regardless of what group I
was in important information was gained which could not have been
obtained any other way but through the double blind process.
BTW in the experiment there are built-in features which will stop the
experiment if benefits are so obvious that it would be unethical to hold
back the treatment from the public and conversely will stop the study if
major adverse events occur in any of the groups.
Thanks for providing a distraction to focus on something besides the
surgery. :-)
Charlie
Phil Tompkins wrote:
> Charles T. Meyer, M.D. wrote:
>
> > I think I may have misunderstood your initial point.
>
> I certainly haven't been clear.
>
> Charles T. Meyer, M.D. wrote:
>
> > As I said before however in the final analysis the value of the
> > procedure has to be evaluated on the basis of substantial clinical
> > improvement (or slowed deterioration) compared to a placebo.
> > Nothing else justifies the risks of that procedure. (fetal
> > transplant) as a regular treatment for PD.
>
> I recognize the power of placebos, but I wonder if there is a way
> around having to use placebo surgery.
>
> It would be silly to require placebo surgery to evaluate hand
> transplants or cosmetic surgery, because the results are right in
> front of our faces. (Ken Becker routine needed here!)
>
> PET scans were used following the fetal tissue transplants to record
> any increases in dopamine activity. In the not too distant future
> there may well be advances in imaging techniques that allow us a form
> of visual access by which we will see whether dopamine activity is
> due to the transplanted tissue itself.
>
> Phil Tompkins
> Hoboken NJ
> age 61/dx 1990
--
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Charles T. Meyer, M.D.
Middleton (Madison), Wisconsin
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