Alan McLean ([EMAIL PROTECTED]) wrote:
: There is certainly an argument that when trialling a new treatment (I
: initially used the word 'testing' here, but figure that it may be
: confused with the statistical test of the resultant data) it is
: presumably expected to work. Consequently, if a person in the trial is
: given a placebo, there is a clear expectation that he or she is being
: disadvantaged - given an inferior treatment.
Placebo controlled trials are unethical and often illegal when placebo
means withholding standard medical care.
: On the other hand, if a placebo is not used, the results of the trial
: will be unclear. This will presumably disadvantage Society. The ethical
: choice is then between disadvantaging a number of individuals by giving
: them a treatment which is expected to be inadequate (rather than a
: treatment which is expected to be better - but may not be!) and
: disadvantaging society by reducing the increase in knowledge - which is
: expected to advantage many people in the future.
Controls need not be placebos. The usual control is standard medical
care. Standard medical care changes. For example, it olden times (like
10 years ago) you could do a placebo controlled trial in subjects with
cholesterols of 240 mg/dl. Today, they get referred to their physicians!
: This is certainly an ethical question (though I might argue that neither
: choice is unethical if the choice is made ethically!) But I don't see
: how the type of statistical test done in analysing the resultant data
: can be ethical or not.
A one-tailed test (as usually proposed) presumes that the difference, if
there is one, can only be it a specified direction.
This violates the principle of equipoise.
=================================================================
Instructions for joining and leaving this list and remarks about
the problem of INAPPROPRIATE MESSAGES are available at
http://jse.stat.ncsu.edu/
=================================================================
