Category Archives: Medicine

Spotty Deference

The public often defers to medical experts, but not always:

Imagine you are seated at a table with two bowls in front of you. One contains peanuts, the other tablets of the illegal recreational drug MDMA (ecstasy). A stranger joins you, and you have to decide whether to give them a peanut or a pill. Which is safest? You should give them ecstasy, of course. A much larger percentage of people suffer a fatal acute reaction to peanuts than to MDMA. … 

As New Scientist went to press, the UK government's Advisory Council on the Misuse of Drugs was widely expected to recommend downgrading it, based on evidence of its limited harmfulness (see "Ecstasy's legacy: so far, so good"). Yet the government has already rejected the advice.

No doubt this is partly a reaction to the furore over the government's de facto decriminalisation of cannabis in 2004, based on another advisory council recommendation. Despite the fact that the move actually reduced the quantity of cannabis being smoked … the government recently reversed it in the face of implacably bad press.

For evidence of how irrational and lacking in perspective the public debate has become, consider how the advisory council's chairman, David Nutt, found himself in hot water last weekend for comparing the harm caused by ecstasy to the harm caused by horse riding.

How does the public decide when to believe medical experts and when not to?  

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Avoid Vena Cava Filters

Shannon Brownlee warns us:

We tend to reward innovation in medicine for innovation's sake. Here's an example: there are, oh, on the order of at least 10 different companies all making a device called a vena cava filter. Each one claims superiority on the basis of some innovation in design. But do vena cava filters actually improve outcomes? Surgeons have been using these things for decades, yet they've never actually put them to the real test of efficacy. The French finally did, and it looks like for most patients the devices don't add value, they just add risk and cost. Now, we probably want to do another study just to be sure, but what's the value of innovation in vena cava filters if you aren't going to find out if they actually help patients.
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Free Docs Not Help Poor Kids

I don't find it surprising when studies of American/European health care consumption show little relationship between consumption and health outcomes. … But I confess I am shocked that studies show the same thing in the developing world:

That is Megan McArdle, on this Gates-funded randomized test of free medicine:

2,194 households containing 2,592 Ghanaian children under 5 y old were randomised into a prepayment scheme allowing free primary care including drugs, or to a control group whose families paid user fees for health care (normal practice) … The primary outcome was moderate anaemia (haemoglobin [Hb] < 8 g/dl); major secondary outcomes were health care utilisation, severe anaemia, and mortality. At baseline the randomised groups were similar. Introducing free primary health care altered the health care seeking behaviour of households; those randomised to the intervention arm used formal health care [12%] more and nonformal care [10%] less than the control group. Introducing free primary health care did not lead to any measurable difference in any health outcome. … Anaemia was chosen as the primary outcome because it is the most commonly used objective outcome of community interventions on malaria morbidity, with malaria the most common life-threatening disease of children under 5 y of age in West Africa.

I am, alas, not surprised.

Added:  PLOS Medicine couldn't publish the above study without also publishing a criticism:

Several biases have led the authors to judge its success on a very limited basis: (1) although the scheme benefits all members of participating households, the study only took into account a sub-population of beneficiaries (children); (2) in this sub-population, only health-related impacts were considered, and among all possible health benefits, only the potential gains in malaria-related outcomes were considered; and (3) among malaria-related outcomes, the analysis was restricted solely to one indicator: the prevalence of severe and moderate anaemia. … The study's authors conclude: "This lack of any effect, including on secondary outcomes such as Hb for which the study had good power, challenges the assumption that where introducing free health care leads to changes in utilisation, it can safely be assumed to translate into health benefits. Given the potential size of resources involved in providing free health care that could be diverted from other priorities on the basis of that assumption, this finding is potentially important for policymakers." But given the methodological limitations of the study, we believe that the trial provides no scientific evidence on the effectiveness of the pre-payment scheme.

Geez.  Translated: as long as any possible studies have not yet been done, there can be no evidence that med $ doesn't help.

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“It is Simply No Longer Possible to Believe”

This piece by Marcia Angell in the New York Review of Books, while very good, mostly consists of stuff that would be familiar and unsurprising to OB readers.  But I was somewhat surprised that she went so far as to say this:

The problems I've discussed are not limited to psychiatry, although they reach their most florid form there.  Similar conflicts of interest and biases exist in virtually every field of medicine, particularly those that rely heavily on drugs or devices.  It is simply no longer possible to believe much of the clinical research that is published, or to rely on the judgment of trusted physicians or authoritative medical guidelines.  I take no pleasure in this conclusion, which I reached slowly and reluctantly over my two decades as an editor of The New England Journal of Medicine.

That's pretty strong stuff for someone who is enough of an establishment figure to become the editor of the NEJM.  It's worth pointing out, though, that most of the biases that she is talking about are the product of plain old financial corruption, not the subtle cognitive biases that we mostly worry about here (though those undoubtedly play a role in allowing physicians to delude themselves into believing that they are not being swayed by the money).  So these kinds of problems could probably be mostly eliminated by a conceptually simple (though of course politically very difficult) change in the rules of the game.  Getting rid of problems like physician overconfidence would be much harder.
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Hated Because It Might Work

Imagine someone who wanted their body dumped into an active volcano when they died, in order to really be one with Earth.  Even if this cost tens of thousands of dollars, few people would dump a significant other, or divorce a spouse, for this. Sure it is a bit weird, but hardly a deal-breaker.  Yet people do commonly divorce spouses for wanting their body dumped in liquid nitrogen at a similar expense, to live again.  (Bryan Caplan is aghast.)  What is the difference?  Two possibilities:

  1. Even though skepticism about whether cryonics will work is one of the main arguments against it, in fact people think there's a substantial chance cryonics might actually work.  This triggers an abandonment reaction, like your buying a one-way-ticket to a distant land from which you could never return.  And it creates uncertainty about whether you are actually dead, making it harder for loved ones to have closure after a funeral.  This is the reason my wife gives for intending to prevent my being frozen. 
  2. Saying you want to do something weird for value or symbolic belief reasons is far less threatening than saying you want to do something weird for instrumental reasons.  Common social norms encourage acceptance of weird values and symbolic beliefs, as long as those don't much effect ordinary behavior.  But by saying your weird act is a much better way to achieve important ordinary goals, you are saying the rest of us are making a big mistake. 
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Cryonics Is Cool

Get_froze1 

By Fortune Elkins.

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We Agree: Get Froze

My co-blogger Eliezer and I may disagree on AI fooms, but we agree on something quite contrarian and, we think, huge:  More likely than not, most folks who die today didn't have to die!  Yes, I am skeptical of most medicine because on average it seems folks who get more medicine aren't healthier.  But I'll heartily endorse one medical procedure: cryonics, i.e., freezing folks in liquid nitrogen when the rest of medicine gives up on them. 

Yes even with modern anti-freezes, freezing does lots of damage, perhaps more than whatever else was going to kill you.  But bodies frozen that cold basically won't change for millennia.  So if whole brain emulation is ever achieved, and if freezing doesn't destroy info needed for an em scan, ifs we think more likely than not, future folks could make an em out of your frozen brain.  Since most folks who die today have an intact brain until the rest of their body fails them, more likely than not most death victims today could live on as (one or more) future ems.  And if future folks learn to repair freezing damage plus whatever was killing victims, victims might live on as ordinary humans.

Now there are a few complications:

Continue reading "We Agree: Get Froze" »

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Animal experimentation: morally acceptable, or just the way things always have been?

Following the announcement last week that Oxford University’s controversial Biomedical Sciences building is now complete and will be open for business in mid-2009, the ethical issues surrounding the use of animals for scientific experimentation have been revisited in the media—see, for example, here , here, and here.

The number of animals used per year in scientific experiments worldwide has been estimated at 200 million—well in excess of the population of Brazil and over three times that of the United Kingdom. If we take the importance of an ethical issue to depend in part on how many subjects it affects, then, the ethics of animal experimentation at the very least warrants consideration alongside some of the most important issues in this country today, and arguably exceeds them in importance. So, what is being done to address this issue?

In the media, much effort seems to be devoted to discrediting concerns about animal suffering and reassuring people that animals used in science are well cared for, and relatively little effort is spent engaging with the ethical issues. However, it seems likely that no amount of reassurance about primate play areas and germ-controlled environments in Oxford’s new research lab will allay existing concerns about the acceptability of, for example, inducing heart failure in mice or inducing Parkinson’s disease in monkeys—particularly since scientists are not currently required to report exactly how much suffering their experiments cause to animals. Given the suffering involved, are we really sure that experimenting on animals is ethically justifiable?

In attempting to answer this question, it is disturbing to note some inconsistencies in popular views of science. Consider, for example, that by far the most common argument in favour of animal experimentation is that it is an essential part of scientific progress. As Oxford’s oft-quoted Professor Alastair Buchan reminds us, ‘You can’t make a head injury in a dish, you can’t create a stroke in a test tube, you can’t create a heart attack on a chip: it just doesn’t work’. Using animals, we are told, is essential if science is to progress. Since many people are apparently convinced by this argument, they must therefore believe that scientific progress is something worthwhile—that, at the very least, its value outweighs the suffering of experimental animals. And yet, at the same time, we are regularly confronted with the conflicting realisation that, far from viewing science as a highly valuable and worthwhile pursuit, the public is often disillusioned and exasperated with science. Recently, for example, people have expressed bafflement that scientists have spent time and money on seemingly trifling projects—such as working out the best way to swat a fly and discovering why knots form—and on telling us things that we already know: that getting rid of credit cards helps us spend less money, and that listening to very loud music can damage hearing. Why, when the public often seems to despair of science, do so many people appear to be convinced that scientific progress is so important that it justifies the suffering of millions of animals? Continue reading "Animal experimentation: morally acceptable, or just the way things always have been?" »

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If You Snooze, You Lose

Jim Horne argues we get plenty of sleep:

The apparent desire for more shut-eye, together with oft-repeated assertions that our grandparents slept longer, all too easily leads to the conclusion that we in the west are chronically sleep-deprived. … [Such] Claims … are nothing new – in 1894, the British Medical Journal ran an editorial warning that the "hurry and excitement" of modern life was leading to an epidemic of insomnia.  …

Over the past 40 years, there have been several large studies of how much sleep people actually get, and the findings have consistently shown that healthy adults sleep 7 to 7.5 hours a night. The well-known "fact" that people used to sleep around 9 hours a night is a myth. …

Continue reading "If You Snooze, You Lose" »

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Toilets Aren’t About Not Dying of Disease

I’m not nearly as far gone as Robin on the idea that social status is the predominant human motivation, but here is a pretty powerful example from an interview with British journalist Rose George about her new book, "The Big Necessity: The Unmentionable World of Human Waste and Why It Matters" (I haven’t read it, but I’ve read a bit about it, and Tyler Cowen recommends it).  Excerpt below the jump.

Continue reading "Toilets Aren’t About Not Dying of Disease" »

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