Well...uhmmm...you know...they are similar...but different...I mean...it
seems like the difference is pretty close to zero....uhmm...actually
1.6%...if we used this to calculate NNH it would be 63...well quite a
discrete number...I suppose...I wonder about the confidence interval around
those numbers....oh yes...statistics!...that is the field of science that we
use to find out if two numbers are the same or different...I guess...
I took the time to review the minutes of the meeting at the FDA (public
documents on the web) on Rezulin which are funny in the sense that they have
transcribed all the jokes during the session. What is not funny is the
amount of numerical spin and extrapolations and calculations used to come up
with the real measure of risk. The FDA and the drug company's estimates are
very different by orders of magnitude! This underscores the difficulties
people have when events are rare (like side effects) compounded by the
wishful thinking of all those involved - nobody wants to see an effective
drug go away.
In terms of pivotal studies for FDA approval, if I am not wrong, these
studies are primarily about safety however they are powered for efficacy
measures and so they are likely to be underpowered to show differences in
rare events, such as in this case - and that is one of the reasons we have
phase IV postmarketing surveillance studies (and individual patient data
meta-analysis).
I don't see a clear way around this problem except for honest reporting and
tight vigillance.
V
-----Original Message-----
From: Simon, Steve, PhD [mailto:[log in to unmask]]
Sent: Monday, March 12, 2001 10:40 AM
To: [log in to unmask]
Subject: Qoute from Warner-Lambert about Rezulin
There was an interesting article about Rezulin in Sunday's paper. I'm sure
most of you are familiar with this, but this drug was taken off the market
recently in the United States because of problems with side effects like
liver failure. There is some question about whether the Food and Drug
Administration approved the drug too hastily.
There was one quote in particular that caught my eye. During the approval
process, the company noted that 2.2% of the patients receiving Rezulin had
liver problems compared to 0.6% of the placebo group. The company
characterized these two rates as "comparable".
In defending that characterization, Randall Whitcomb (vice president for
diabetes research) testified as follows:
"'Comparable' is, is, you know, is an interesting word. Is 2.2 percent
different than 0.6 percent? ... I think you could look at 2.2 and 0.6 and
say that those are similar numbers, you know, when you look at this now. I
mean, 'similar' is a -- is a very broad term ... I don't think that these
numbers are, are all that different."
Anyone care to comment on this quote? Are 2.2 and 0.6 percent similar or
comparable numbers in this context?
Steve Simon, [log in to unmask], Standard Disclaimer.
STATS: STeve's Attempt to Teach Statistics. http://www.cmh.edu/stats
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