Results for “first doses first” 93 found
James Hamilton takes a look at one of the key studies on Vioxx and heart attacks. He is not greatly impressed.
I took a look at one of the studies on which the decision was
justified, written by Dr. David Graham and co-authors and published in Lancet
in February. This study looked at 8,143 Kaiser Permanente patients who
had suffered a heart attack and had also at some point taken a
nonsteroidal anti-inflammatory drug (NSAID), of which Vioxx (rofecoxib)
is one. Of these patients, 68 were taking rofecoxib while 4,658 were
receiving no medication at the time of their heart attack, a ratio of
(68/4658) = 1.46%. For comparison, the study looked at 31,496 other
patients who had also at some point taken an NSAID, matched for
characteristics like age and gender with the first group, but who
didn’t have a heart attack. The ratio of rofecoxib users to those with
no current medication was slightly lower (1.05%) in this second group,
which one might summarize as a (1.46/1.05) = 1.39-fold increase risk of
heart attack from taking rofecoxib compared to no NSAID. Is that
statistically significant, in other words, can you rule out that you’d
see a difference of that size just by chance? Yes, the study claimed,
but just barely.
On the other hand, this was not a controlled experiment, in which
you give the rofecoxib randomly to some patients and not others in
order to see what happens. Rather, something about either these
patients or their doctors led some of them to be using rofecoxib and
others not. Dr. Graham and co-authors looked at a variety of indicators
that suggested that the rofecoxib patients already had slightly
elevated risk factors for coronary heart disease. Once they controlled
for these with a logistic regression, their study found an elevated
risk factor of heart attack for rofecoxib takers of 1.34, which was not
statistically significantly distinguishable from 1.0.
The strongest evidence from this study was a claimed dose-effect
relation. Of these 68 rofecoxib-using heart-attack patients, 10 of them
were taking doses above 25 mg per day. Only 8 patients in the much
larger control group were taking so high a dose, implying an elevated
risk factor of 5 to 1 for high-dose patients. Again observable risk
factors could explain some of this, with the conditional logistic
regression analysis bringing the implied drug-induced risk down to 3 to
1. According to the study, this elevated risk factor was still
statistically significant, even though the inference is based on the
experience of just 10 patients.
The obvious question here is whether in fact the authors were able
to observe all the relevant risk factors. The study openly acknowledged
that it did not, missing such important information as smoking and
family history of myocardial infarction.
there actually is an elevated risk of the magnitude the studies suggest
but can’t prove, the question is whether I might want to accept a 1 in 4,000 risk of dying from a heart attack in order to get the only medication timt makes my pain bearable and a mobile life livable. And if I say no to the Vioxx, I may end up taking something that is less effective for my pain but has risks of its own.
…. How did we arrive at a
system in which 12 random Texans are assigned responsibility for
evaluating the scientific merits of statistical evidence of this type,
weighing the costs and benefits, and potentially sending a productive blue-chip American company into bankruptcy protection?
See also my op-ed Bringing the Consumer Revolution to the FDA.
The flu vaccine is now running very scarce, you can wait for weeks and there is no guarantee of getting it at all. Most of the supplies are already in the hands of doctors. Note also the following:
Random immunization is almost useless because, for many viruses, more than 95% of the population must be vaccinated to prevent the disease’s spread.
But things are not as grim as they might sound. First:
An alternative to the flu shot is FluMist, a more expensive inhaled version of the vaccine, which is recommended for healthy people between the ages of 5 and 49. There are about 4 million doses available of FluMist, health officials said.
Although those below 5 and over 49 are the at-risk groups, they are less likely to catch the flu if the rest of us are healthy.
Second, we could administer flu shots more wisely by targeting superspreaders, here is one proposal:
Reuven Cohen of Bar-Ilan University in Israel and his colleagues propose a simple modification of random vaccination that is more effective, according to their computer simulations. The idea is to randomly choose, say, 20% of the individuals and ask them to name one acquaintance; then vaccinate those acquaintances. Potential super-spreaders have such a large number of acquaintances that they are very likely to be named at least once, the researchers found. On the other hand, the super-spreaders are so few in number that the random 20% of individuals is unlikely to include many of them.
Using the team’s vaccination strategy, a disease can be stopped by vaccinating less than 20% of the individuals, in some cases, according to their computer model of a human population. The method can also be tweaked: if a larger sample is asked for names, and those named twice are vaccinated, the total number of vaccinations required can be even lower.
The trick may be getting these people to take the shots, but surely economists can come up with a useful incentives scheme for that, I would prefer a subsidy over a tax.
Last year the highest-earning British artist was Damien Hirst, the creator who cuts up dead sharks and puts them in formaldehyde. He pulled in twelve million British pounds last year (over twenty million dollars), although dealer’s commissions may have eaten into this figure. As an aside, many buyers of Hirst’s early dot paintings, see the link for an image, are unhappy because most of those works were made with ordinary household paints and are now falling apart.
A close second on the earnings list was Andrew Vicari, now resident in Monte Carlo, since 1974 he has been the official painter to the Saudi Royal Family.
What a pair. Hirst I admire for his visceral impact but I could not live with most of his works, not the least because some of them involve live, buzzing insects. Would you wish to own “the beauty of a disused shop full of butterfly pupae, hatching from white canvases, feeding on sugar syrup, mating, laying eggs and dying”? Or rather would you call the exterminator to get rid of something like that?
I wouldn’t hang a Vicari on my walls, check out his painting of the first Gulf War. I now have a better understanding why the Saudi Royal Family is in such trouble.
But let us look at the bright side. No one (well, hardly anyone) ever said capitalism was about rewarding people in accord with their merits. An unequal distribution of rewards is part of the system that generates more diverse art of many kinds, click here to see a compelling portrait by Lucien Freud, or here for a broader choice of images. Click here for a sparkling Howard Hodgkin, here for a broader choice of Hodgkin images, which always bring a splash of color. They are the British painters I will buy when they start paying bloggers.
The earnings information is from The Art Newspaper, one of the highest quality periodicals of any kind.