Category: Medicine

Cadaveric vs Live Organ Donation

The basic point is simple – financial incentives for cadaveric donation of organs would save lives and would also reduce the demand for live donation, a costly and difficult procedure. (See my previous posts on this issue here and here). Tyler’s post obscures the basic point by introducing a debate about “a truly free market in organs” by which he means allowing payment for live donors. I won’t be drawn into that debate today, not because it isn’t an interesting issue, but because it is not germane to the issue of financial incentives for cadaveric donation. We should have the latter regardless of our position on the former. Note also that for obvious reasons live donation primarily affects kidneys only and doesn’t reach the issue of how to save the lives of transplant patients who needs hearts, lungs and other organs.

Sleazeball lawyer in a low-cut dress

I am speaking of Erin Brockovich. Sure, I liked the movie but the true story on which it was based was a lie. There was no cancer cluster in Hinkley, no scientific theory of harm, no coverup at the water office (see here for links). Having had one success in Hollywood, Brockovich is now after another this time by fanning hysteria that the kids at Beverly Hills High School (yes, 90210) are getting cancer from a nearby oil well. I smell a movie in the works.

End Phase 3

Harvard neurologist Peter Lansbury argues in the WP that we should end mandatory Phase 3 clinical trials for new pharmaceuticals. Aside from the expense of Phase 3 trials (hundres of millions of dollars) and years of delay he writes that:

There are also scientific reasons to replace Phase 3. The reasoning behind the Phase 3 requirement — that the average efficacy of a drug is relevant to an individual patient — flies in the face of what we now know about drug responsiveness. Very few drugs are effective in all individuals. In fact, most are not effective in large portions of the population, for reasons that we are just beginning to understand.

It’s much easier to get approval for drugs that are marginally effective in, say, half the population than drugs that are very effective in a small fraction of patients. This statistical barrier discourages the pharmaceutical industry from even beginning to attack diseases, such as Parkinson’s, that are likely to have several subtypes, each of which may respond to a different drug. These drugs are the underappreciated casualties of the Phase 3 requirement; they will never be developed because the risk of failure at Phase 3 is simply too great.

Lansbury also recognizes the importance of off-label prescribing and how it flies in the face of FDA power.

Once the FDA has approved a drug based on its effectiveness against one condition, it can be prescribed for any other condition. This practice recognizes that your physician is best equipped to evaluate all the available information and advise whether you could benefit from a particular drug. About 40 to 50 percent of all drug use is for such unapproved, or “off-label,” uses. Some drugs that “failed” in Phase 3 trials for one condition, but were approved for another, are still widely prescribed for the first because physicians agree that the evidence shows they can be effective.

I agree with Lansbury’s analysis and so do a lot of physicians. See my papers Assessing the FDA via the Anomaly of Off-Label Drug Prescriptions and Do Off-Label Drug Practices Argue Against FDA Efficacy Requirements? Testing an Argument by Stuctured Conversations with Experts.

And you think we economists are tough…

Barlow’s method for treating anxiety disorders is surprisingly simple, although its philosophical and clinical implications are anything but. He aims to reduce anxiety not by teaching customary relaxation techniques involving calming mantras or soothing imagery, but by doing just the opposite: forcing the patient to repeatedly face his most dreaded situation, so that, eventually, he becomes accustomed to the sensation of terror. Barlow claims he can rid some people of their symptoms in as little as five to eight days. His treatment promises to be psychotherapy’s ultimate fast track, but while many clinicians praise its well-documented results, others take a dimmer view of what one clinician calls ”torture, plain and simple.”

The economic rationale for this, is, of course, straightforward. Make some form of thought, feeling or behavior more costly, and people will do less of it.

And does it work?

…his success in ameliorating anxiety is by his reckoning as high as 85 percent. David Tolin, the director of the Anxiety Disorders Center at the Institute of Living in Hartford, says: ”Barlow’s program is an ideal toward which other clinicians should strive. It is the most rigorously tested and documented treatment for anxiety. Most practitioners don’t teach his approach because the field of psychology is relatively slow to adapt to evidence-based treatment.” Reid Wilson, a professor of psychiatry at the University of North Carolina School of Medicine and an ardent Barlow supporter, adds that Barlow’s work hasn’t completely caught on because, as he puts it: ”We’re still on the uphill climb. We haven’t had the manpower to train enough people. Only a very small number of clinicians know about this. They don’t understand that relaxation training could actually slow treatment instead of speed it up.”

For the full, and fascinating, story, click here. Here is another article on Barlow. Here is Barlow’s home page.

I don’t have the clinical or medical expertise to evaluate this, but surely it deserves a closer look. The economist, however, should not spring to any quick conclusions. Yes, the “substitution effect” favors a cure, but in the meantime the “income” or “portfolio” effect may drive the individual to very low and possibly counterproductive levels of despair.

By the way, our colleague Bryan Caplan offers this extreme, economistic perspective on mental illness. I think Bryan’s view is crazy; he probably thinks you would be crazy not to read such a short, entertaining polemic.

US Sperm Exports Explode; Canadians Upset

The US is a world leader in sperm exports primarily because sperm banks in the U.S. are run on a for-profit basis. As a result, US sperm is reckoned to be of high quality (we always knew this didn’t we?) particulary because the US version comes with a background on the vitals of the donor. Denmark also exports a lot of sperm because of high standards and demand for that blond, blue-eyed look.

Exports to Canada have increased in recent years because of a scandal involving poorly screened Canadian sperm. Canadians also import a lot of US eggs. The Canadian government, however, is apparently miffed as a new law is being readied that would forbid donations involving a paid donor. The law would not only make paid donation illegal in Canada it would make it illegal to use any paid-for sperm. Canadian couples seeking fertility options will suffer and who will benefit? I cannot think that this law is anything but spiteful and ridiculous. Is paying for sperm an original sin? As with other areas of Canadian medicine (see Tyler’s posts here and here), the rich will now travel to the United States for treatment.

Aside: The Canadian Health Official quoted here is ignorant or disengeneous when she says “We don’t buy or sell blood, or organs or tissues.” In fact, Canada also imports a lot of US blood plasma. Plasma takes longer to donate than straight blood and as a result altruistic donation rates are low and much of the world relies on paid-for US plasma for its life-saving properties. Similarly, donating eggs is not nearly as much fun as donating sperm so altruistic donation of Canadian eggs is unlikely to make-up for restrictions on the import of paid-for US eggs.

Thanks to Eric Crampton for the seminal email.

Suicide and multiple equilibria

I don’t aim to be the cynical economist that Tyler writes “might suggest social stigma for suicide, rather than forgiveness” but it is frightening how easy it seems to be to jump to the sad equilibrium. The story of suicide among young boys in Micronesia (I recommend Malcolm Gladwell’s The Tipping Point for a discussion but will cite some online material) illustrates how actions and social attitudes reinforce one another. As the action becomes more common, perhaps reaching a “tipping point”, condemnation declines, and the action increases even further. Here, from one of the researchers who first documented the story, is a chilling description of suicide in Micronesia:

As suicide has gained familiarity among youth, the act itself has become increasingly more acceptable or even expected. Suicides appear to acquire a sort of contagious power. One suicide might serve as the model for successive suicides among friends of the first victim. There has been an apparent increase in suicides among very young children, aged 10-14. Evidently the idea of suicide has become increasingly commonplace and compelling, and young children are now acquiring this idea at earlier ages.

Another of the earlier researchers writes:

Love songs mention suicide, youths discuss the subject openly among themselves and at times make suicide pacts with one another, and youngsters express admiration of those who have taken their own lives and are mourned so terribly by their families and friends. What is even more shocking, however, is that a number of adults in our communities seem to share the belief that these young people have died altruistic and even heroic deaths. If the majority of Micronesians really believe that suicide is an honorable option, then this paper is thoroughly useless and all of us had better resign ourselves to continuing high rates of suicide in the future. Young people, after all, are very quick in sensing the basic values of their elders. If they get the impression that we ourselves honor suicide, then they will be only too happy to oblige by hanging themselves.

Note that one could tell similar stories in the United States about divorce, having children out of wedlock, welfare dependence etc. (also teenage suicide at a local level).

Here is a graph of suicide rates in Micronesia indicating a massive increase in a few short years in the early 1970s. The tipping theory generates credence when we note that virtually all the suicides take a similar, ritualistic form involving hanging.
suicide.bmp

Dalkon Shield, Silicone Breast Implants, Fen-Phen

A bill to move class action lawsuits out of the state courts and into federal courts narrowly failed in the Senate. Senator Tom Daaschle, explained his opposition to the bill this way, “It is the Dalkon shield, it is silicone breast implants, it is fen/phen.”

Good list. Wrong conclusion. The A.H. Robins Co. was driven into bankruptcy and forced to pay 3 billion dollars in damages but the Dalkon shield has been shown to be effective and safe. Silicone breast implants have been reviewed in studies by the AMA, the Institute of Medicine, the Canadians, the French, the British and others. All conclude that there are no unusual problems with the implants (any surgery has risks of course). The FDA will probably soon allow the implants back onto the market but in the meantime Dow-Corning has been driven into bankruptcy and tens of millions of dollars have been spent on lawsuits. Fen/Phen does looks like a serious health risk but tort law had nothing to do with removing the product from the marketplace. (Moreover, the issue is complicated. Only the Fen in Fen/Phen looks dangerous and that was approved in 1973).

We should spend More on Health Care

Tyler appears to be growing more skeptical of the value of health care spending (see his posts here and here). A simple model explains most of what is going on and why he and another of my very smart colleagues Robin Hanson, are wrong. In the graph below spending on health care is on the X axis, health outcomes are on the Y axis. Spending shows diminishing returns. We are currently at point Q on the graph labeled T1 – note that at this point marginal increases in spending have little effect on output (Tyler asks, What margin has low value? Answer: The marginal dollar). Even fairly large increases or decreases in spending will not change outcomes very much given that we are currently at point Q.

Why are we spending so much as to push us into the flat portion of the production function? One reason is that out-of-pocket expenses for medical care are much lower than true costs – we typically are spending someone else’s money. A second reason is that the marginal utility of wealth is low if you are dead so spending on health care near the end of life has unusually low opportunity cost. A third reason may be that various psychological factors make the desire to avoid regret particulary strong for health care, as Tyler speculated earlier.

Although the marginal dollar has low return the value of improvements in medical technology is enormous. These gains are illustrated by the shift from T1 to T2. It has been estimated, for example, that increases in life expectancy from reductions in mortality due to cardiovascular disease over 1970-1990 has been worth over $30 trillion dollars – yes, 30 trillion dollars (for this research see: book, papers, summary). A conservative estimate is that 1/3rd of these improvements in life expectancy were due to better medical technology. One third of the annual benefits is $500 billion – this is much more than total government spending on medical research (the budget of the entire NIH is around 25 billion).

The low value of medical spending at a particular point in time and the high value of medical research over time suggest that we would be much better off if we cut back on medical care spending and devoted the funds to medical research. We should spend less on Medicaid, Medicare, Prescription drug plans etc. and use the savings to better fund the NIH (or other methods of increasing medical research such as prizes etc.)

HealthModel.JPG

Notes on Genetic Insurance

My idea of genetic insurance created some controversy with Randall Parker at FuturePundit, Brock Sides at Signifying Nothing, and MR’s guest blogger Lloyd Cohen raising some objections. One of the objections that all three had in common (dealt with in my papers but not in the post) is that adverse selection is still a problem if people lie about having taken a test. This minor problem is easily handled, however. Insurance companies could have a clause in the contract forbidding previous tests. We don’t worry so much about people having a theft and then buying home insurance and the issue here is quite similar. (See my papers for a little more on this issue).

Randall at FuturePundit, however, raises a more serious problem. As the price of genetic tests falls it will soon be economic to sequence a person’s entire genome at birth or even before (see Randall’s posts for some links on costs). In this case, genetic insurance works only if the parents buy the insurance. This is not so implausible (especially not for those who have their child’s DNA sequenced!) but it is a real issue. (We should also remember that genetic insurance will be quite cheap because most people do not have serious genetic defects.) If we have genetic insurance today, however, we can perhaps avoid the adverse selection problem for a couple of decades and that may be good enough for one of two things to happen 1) genetic engineering will reduce the need for insurance (sequencing is much more valuable if there is genetic engineering to correct defects) or 2) genetic insurance could evolve into a more Rawlsian scheme (perhaps involving government at some level) in which payments are made at birth to compensate for Nature’s genetic lottery.

The case for health care spending

In a previous post I wondered whether additional spending on health care in fact brought greater health. Whether we do controlled experiments, or look at cross-national data, a convincing effect is often hard to find.

Brendan Kennelly of Lehigh referred me to this OECD paper, which examines cross-national data to find a positive health effect from health care spending. The result is much stronger for women than for men.

I asked Robin Hanson what he thought of the piece, here is his response:

When a coefficient is truly zero, about 5% of the studies estimating that
coefficient should show a significant difference at the 5% level. And if
people search for specifications that will give this result because they
believe the coefficient is not zero, you might expect 10-20% (or more) of
the reported results will show a significant non-zero coefficient. So
given the current state of econometric practice, the most you could
reasonably hope for when a coefficient is really zero is for about 90% of
the studies to fail to find a significant effect of the desired sign. This
is the current state of the evidence on the aggregate effects of medicine
on health.

My take: The whole debate still makes may head spin. I wonder how much of health care expenditure is geared toward alleviating anxiety (“we did all we could…”) rather than improving health per se. We may be mismeasuring the relevant output. If we could measure the total costs of illness, what percentage of the total would come in the form of anxiety? Furthermore, health care is not a single thing. The marginal return from some forms of health care (bypass operations?) is certainly high, in other cases the return much lower or perhaps negative. So perhaps the debate should shift away from aggregates, and toward trying to identify which health care expenditures we can do without, or do not need to subsidize at current margins.

The wonders of money

…lifting children out of poverty can diminish some psychiatric symptoms…A study published in last week’s issue of The Journal of the American Medical Association looked at children before and after their families rose above the poverty level. Rates of deviant and aggressive behaviors, the study noted, declined as incomes rose.

“This comes closer to pointing to a causal relationship than we can usually get,” said Dr. E. Jane Costello, a psychiatric epidemiologist at Duke who was the lead author.

The study tracked 1420 children, many of whom lived on an Indian reservation. A local casino opening lifted many out of poverty, and also improved their mental health:

…the rate of psychiatric symptoms among the children who had risen from poverty was dropping. As time went on, the children were less inclined to stubbornness, temper tantrums, stealing, bullying and vandalism – all symptoms of conduct and oppositional defiant disorders.

After four years, the rate of such behaviors had dropped to the same levels found among children whose families had never been poor. Children whose families broke the poverty threshold had a 40 percent decrease in behavioral symptoms. But the payments had no effect on children whose families had been unable to rise from poverty or on the children whose families had not been poor to begin with.

Even I, author of a book called In Praise of Commercial Culture (see to the right), am surprised by this result. Supposedly the wealthier parents were now able to spend more time with their children, thus improving their mental health. I wonder whether the key factor instead might have been improved behavior on the part of the parents.

Here is the abstract, plus you can buy a copy of the original research for $12.

Addendum: David Levy, citing Adam Smith, wonders if it isn’t the growth rate of income that makes people better off, rather than the level.

The doctor drain from Canada

Unlike most libertarian-oriented economists, I find persuasive the left-wing arguments that individuals have a positive right to medical care. The problem is, most governmental systems are proving unsustainable in the long run. They are affordable only by rationing, which frustrates doctors and patients alike. The Canadian system is (barely) tolerable, only because so many Canadians come to this country for their care.

Read this article from The New York Times.

Here is one money quote:

Forced to compete for operating room time with other surgeons, he said that he and his colleague could complete only one or two operations on some days, meaning that patients whose cases were not emergencies could go months or even years before completing necessary treatment.

“Scarce resources are simply not being spent properly,” Dr. Sriharan concluded, citing a shortage of nurses and anesthesiologists in the hospital where the single microscope available is old and breaking down.

The two surgeons are sharply critical of Canada’s health care system, which is driven by government-financed insurance for all but increasingly rations service because of various technological and personnel shortages. Both doctors said they were fed up with a two-tier medical system in which those with connections go to the head of the line for surgery.

Here is another:

There was a net migration of 49 neurosurgeons from Canada from 1996 to 2002, according to the Canadian Institute for Health Information, a large loss given that there are only 241 neurosurgeons in the country.

My take: It is only going to get worse.

More on placebos

Alex, in his blog post from earlier today, makes a good point about placebos. Sometimes the patient is getting better anyway, and we should not attribute this effect to a placebo.

Note, however, that the best-known “anti-placebo” study is not as strong as is commonly believed. It relies heavily on a meta-analysis of other studies. Placebos appear to be effective in relieving the sufferer of pain, if nothing else. And placebos appear more effective when the ailment is continuous rather than discrete. Furthermore it is unclear how many people in the so-called no-treatment groups in fact received no treatment at all.

Here is a defense of the placebo effect. Placebos also have measurable effects in the brain, comparable to those of drugs, though weaker or less persistent.

Robert Ehrlich’s Eight Preposterous Propositions offers a very good survey of the placebo debates. His conclusion:

In summary, the [critical] study may have shown that the placebo is not as powerful as some observers would believe, but it certainly is far from powerless.

By the way, did you know that people can become addicted to placebos, or suffer from harmful “side effects”? I’ll try to write more on “nocebos,” or negative placebos, soon, at least provided that my mental attitude holds up.

Defining the Placebo Effect Carefully

I agree with Tyler that there is some serious evidence for placebo effects, especially although not exclusively for subjective components of disease. But the evidence is usually overstated because it is confused with the natural tendency of sick people to get better. A typical medical study, for example, will compare the results of a new drug against a placebo. The improvement in health of those on the placebo is then labeled “the placebo effect” – but this is wrong. To correctly identify the effect of the placebo one needs three randomly selected groups – a treated group, a placebo group and a non-treated group. The effect of the placebo per se is then measured by the health differences between the placebo and non-treated group. Although spontaneous healing effects are large, placebo effects when measured correctly tend to be small although not non-existent.

Fingers

Of the strange beliefs that Tyler examines he finds craziest the idea that slender hands might signal artistic ability. Maybe, but you know what they say about truth and fiction. Recent research indicates that finger length relative to height and the relative length of the ring to index finger can predict a great deal about male depression and intelligence, who is most at risk for heart attacks and sexual orientation. The theory is that testosterone and other hormones like androgen are the direct causes but fingers are a particulary good marker for hormone production.