Friday, March 3, 2006
We got a lot of mail last week about our comment on these popular
dietary supplements. Based on an NIH-funded trial, reported in
the New England Journal of Medicine, WN characterized G-C as
"ineffective" for osteoarthritis knee pain. The study reported
that: "Overall, glucosamine and chondroitin sulfate were not
significantly better than a placebo in reducing knee pain by 20
percent." The double-blind trial was placebo controlled, and
celecoxib (Celebrex) was used as a positive control. The problem
is that the 1583 patients in the trial were divided into subsets
based on severity of pain. Although it was ineffective overall,
indignant WN readers pointed out that for the moderate-to-severe
subset G-C "provided statistically significant pain relief
compared to a placebo." Statisticians groaned: by dividing the
cohort into subgroups, the outcome for a specific subset can
usually be altered by fiddling with the boundaries. The bottom
line in the NEJM study, incidentally, is the ubiquitous report
ending, "continued research is needed to establish efficacy."
Much of the e-mail about G-C was anecdotal. Not just from people
who used it themselves, but also those who had treated dogs, cats
and horses with it(vets love G-C, and point out that pets don't
respond to placebos). "The plural of anecdote," someone said,
"is data." Although anecdotes are not blind; we decided to see
what the data might tell us about What's New. First we divided
the messages into subgroups. The groups ranged from,"He's just
guessing," to "Park is a liar and must be getting paid under the
table by Pfizer." We're still fiddling with the boundaries.
Two weeks ago, WN commented on satellite data showing glaciers in
Greenland rapidly turning into ocean. Today, Science published
satellite measurements showing rapid melting at the other end.
It had been expected that increased snowfall due to warming would
cause the Antarctic ice sheet to gain mass. Meanwhile, Joseph
Taylor, 1993 Physics Nobel, told the House Science Committee that
small science missions are being cut to feed the shuttle and ISS.
Utah is one of the most conservative states in the nation, but on
Monday, legislation favoring intelligent design lost. Alas, I'm
sure the Discovery Institute will be able to find a new gimmick.
According to an article in Lancet Neurology, German researchers
found that Chinese acupuncture worked about as well as drugs in
treating arthritis, but so did sham acupuncture, in which the
needle is inserted in the wrong place. WN has been saying this
for years (WN 23 Dec 04) .
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