The placebo effect
Online posting: July 25, 1997
Published in print: Oct. 15, 1997 (CMAJ 1997;157:1019)
Re: Bioethics for clinicians: 10. Research ethics, by Dr.
Charles Weijer and associates, CMAJ
1997;157:1153-7 [full text / résumé]
See response from: C. Weijer
I was glad to note that Dr. Weijer and associates mention the
special circumstances involved when incompetent patients are
recruited into clinical studies. In the population of cognitively
impaired frail elderly people, this is a critical issue. If we
exclude these patients en masse from all clinical trials, how can
we turn around and generalize studies to this special population?
I find the ethics of placebo-controlled studies difficult to
deal with. The authors state that, when studying a condition for
which standard treatment exists, "it is unethical (since placebo
is an inferior 'treatment') to expose patients to the risk of
'treatment' with placebo alone." Although the concept of clinical
equipoise is powerful and easily understood, I wonder what the
precise role of placebo-controlled studies is. As new drugs are
developed and marched through phase I and II studies, it is very
difficult to find no circumstances in which they should be
compared with placebo to show their efficacy. We cannot justify
large, phase III clinical trials that are placebo-controlled when
standard therapy exists, but what about earlier-stage studies?
When developing drugs, one cannot always compare them with
standard therapy at the outset. And yet, without
placebo-controlled trials, can we ever bring new drugs that are
superior to standard therapy into clinical use?
Shabbir M.H. Alibhai
Richmond Hill, Ont.
s.alibhai@utoronto.ca
CMAJ email
CMAJ Readers' Forum