Category: Medicine

Was Nietzsche right?

In recent weeks there’s been a furor in the Washington D.C. area over lead in the District’s water supply. Today, the Washington Post (registration required) looks at why lead is bad for you and covers some of the science and public policy. That lead is bad for you is open and shut. Too much lead kills you and for kids, too much is not that much. But I am skeptical of recent studies that find that the worst effects of lead happen at the lowest levels of exposure.

Here‘s a typical newspaper account of one of those studies and a quote from a leading researcher on the topic:

“There is no safe level of blood lead,” said Dr. Bruce Lanphear, lead author of the lead study presented Monday at the Pediatric Academic Societies annual meeting.

Edward Calabrese would not agree. Calabrese is a toxicologist at UMass-Amherst and a leading scholar of hormesis, the phenomenon that most if not all toxins are actually good for you at sufficiently low doses. This does not imply that you should start adding mercury to your eggs or lead back into your pots. But the impact of toxins appears to be U-shaped–good for you at sufficiently low levels then bad as exposure increases. Whatever doesn’t kill you makes you stronger.

Hormesis also implies that linear models or threshold models of toxic impact are misspecified and understate the impact of toxins over some ranges of exposure.

Here’s a Scientific American article on Calabrese and hormesis.

Here’s my take on the economics and policy implications of hormesis.

“Curing” Obesity

Researchers claim to have discovered one of the key causes of obese America. The AP reports:

Researchers say they’ve found more evidence of a link between a rapid rise in obesity and a corn product used to sweeten soft drinks and food since the 1970s.

The researchers examined consumption records from the U.S. Department of Agriculture for 1967-2000 and combined it with previous research and their own analyses.

The data showed an increase in the use of high-fructose corn sweeteners in the late 1970s and 1980s “coincidental with the epidemic of obesity,” said one of the researchers, Dr. George A. Bray, a longtime obesity scientist with Louisiana State University System’s Pennington Biomedical Research Center. He noted the research didn’t prove a definitive link.

I like the hedging–the link isn’t “definitive.” No, I guess it wouldn’t be. Obesity is surely also “linked” to the Iran hostage crisis and the stagflation of the late ’70s and early 80s. Maybe I shouldn’t be so skeptical. The study may be a little more scientific than merely looking at correlation rather than causation. But if the research is right, it will be easy to make America thin again. Just ban those high fructose sweeteners. One problem with this will be explaining why the advent of low calories sweeteners didn’t stem the tide of fat that allegedly threatens to overwhelm us.

My theory is that we’re fat because we enjoy it. We like food. It gives us pleasure. We’re wealthy and food’s cheap so we’re taking on a few pounds. Alex points out that the entire increase in weight over the past several decades can be explained by an extra Three Oreo Cookies a day! Here is a paper by Glaeser, Cutler and Shapiro that takes the economists’ approach to weight gain.

Here’s my take on the claim that we should tax fatty foods because of the externalities.

Off-label drugs

Alex has written much about the importance of off-label uses for drugs, which are not generally restricted by the FDA. I came across the following in the 17 March 2004 Wall Street Journal, Marketplace section:

A high-price biotech drug, developed in the 1980s to treat a rare form of hemophilia, is fast becoming a blockbuster, with physicians around the world using it to stanch severe bleeding from car accidents, gunshot wounds and postsurgery hemorrhaging.

But here’s the rub: The drug, a human bloodclotting protein called NovoSeven that costs $5,000 a dose, hasn’t been approved by the Food and Drug Administration for such uses…Some doctors are hailing NovoSeven as a lifesaver, with word spreading about near-miraculous cures of dying patients. It’s the new wonder drug,” says Thomas Scalea, director of the shock trauma center at the University of Maryland Medical Center. He says the center has used the drug 80 times in three years, saving about 35 lives.

Not all doctors agree about the merits of the drug, and insurance companies will not reimburse drug usage for this purpose.

Question: Should the FDA have regulatory power over the off-label use of this drug to stop traumatic bleeding? If it had had such power, would any of these lives have been saved at all? In his paper, Alex asks the requisite follow-up question. If it is bad idea to give the FDA regulatory power over off-label uses why give it so much power over initial uses?

As things stand now, the FDA will not allow “human trials” of the drug in the laboratory, although real life trials occur in hospitals on a regular basis. Furthermore the company’s sales force cannot promote the drug for non-hemophilia uses and must wait for doctors to ask, noting that it employs 25 full-time people simply to handle the flood of inquiries.

Further comment by Alex is welcome. This is his bailiwick not mine, I just thought the example was especially striking. Here is some basic information about the drug, here is the company’s web site.

Further thoughts on artificial hearts

A number of people emailed me or blogged (eg. here and here) on my post, Artificial heart won’t save lives. The number of transplants is constrained by the number of donated organs thus the main effect of the artificial heart, which is just a temporary stop-gap, is to redistribute organs. The artificial heart makes some people better off at the expense of other people who are made worse off. No one challenged this conclusion but it seemed to make some people uncomfortable. Two arguments were raised in opposition, both of which are weak.

First, the heart does allow some people to live a little bit longer – this is a benefit, but a few weeks of life while chained to a big machine doesn’t seem like a big breakthrough to me. Second, the artificial heart could allow for better matching. Theoretically true, but there are already many more patients on the waiting list than there are hearts available so the opportunity for better matching is negligible. Consider, that for a given heart there are now 3500 people on the waiting list to choose from – how much better is the match going to be if we add a few more people to this list?

I am not against artificial hearts (some people say I have one!) perhaps one day the technology will improve enough so that someone on an artificial heart can be taken off the list, but the issue is comparative. Suppose that we put the funds gong into artificial hearts into programs to increase organ donation. One donated organ is say good for 10 years of extra life. Average time on the artificial heat is 77 days and it is not clear how many of these days represent extra days of live. Let’s say very charitably that 50 days are extra then this means that one real heart is worth 73 times as much as an artificial heart (10*365/50) and that is before adjusting for quality of life.

Artificial heart won’t save lives

An FDA panel announced today that they would support approval of a new artificial heart. NPR and other media suggested that the new heart, which is designed only for temporary use and is not portable, would save lives by extending survival time until a transplant became available. But even if the artificial heart performs exactly as designed and even if it prolongs the lives of those who receive it, it won’t save lives overall.

The mathematics is simple; there are approximately 2200 hearts donated for transplant every year (data here). That means we can save 2200 lives a year and no more. All the artificial heart can do, therefore, is change who gets saved. Some people who previously died will live long enough to receive a transplant but this means there will be one less heart available for someone else on the waiting list. The artificial heart will make the waiting list longer but it will not save lives.

The only way we can truly save lives is to increase the number of organ donors. As readers of Marginal Revolution will know I have suggested financial compensation and organ donor clubs as the only realistic solutions.

Why has Russian health collapsed?

The health care collapse in the former Soviet Union is old news, less well known is the contrast between Russia and Poland:

…another Slavic nation with a traditional affection for vodka — Poland — is experiencing one of the greatest improvements in health ever known. The difference tells a story of how democracy has transformed the center of Europe in the past 15 years — and how it has failed in Russia.

Start with the figures. In the early 1980s life expectancies in Soviet Russia and Communist Poland were roughly similar, and both were starting to get worse. Cancer and cardiovascular disease were beginning a rapid rise, in lock step with their prime causes: smoking and alcoholism.

Two decades later, Poland’s life expectancy for men, at 70, has risen by four years since the collapse of communism and now is more than 10 years longer than that of Russian men. In Poland, cardiovascular disease has fallen by 20 percent in a decade, while in Russia, it has risen by 25 percent. Sudden deaths from accidents and other external causes have fallen 19 percent in Poland, while in Russia the rate has soared to an unprecedented level. Poland’s rate of HIV infection is one of the lowest in Europe; Russia has one of the world’s highest rates of new infection.

Polish researcher Witold Zatonski has an explanation for this difference:

…he has boiled his answer down to a simple slogan: “Democracy is healthier.” “It’s the only way to explain what has happened,” he said during a recent visit to Washington. “It turns out that the free-market economy and a free political debate correlate directly with good health in Eastern and Central Europe.”

I was incredulous when I first read this, apparently I was not the only one:

That conclusion used to be doubted by some of Zatonski’s colleagues, both in Poland and in the West. After all, democracy brought Poland freedom for cigarette and alcohol advertising, Western brands, and a parliament presumably susceptible to special interests. Tobacco companies spent $100 million a year on marketing to Poles in the 1990s.

Remarkably, though, all that money and influence have been outweighed by the other products of a free society, especially independent civic organizations and media that promote knowledge and open debate about health issues.

It is well known from happiness surveys (see the work of Bruno Frey) that people are happier in democracies, so maybe there is a link to health as well, even after adjusting for income.

What about the comparative statics?

In addition to Poland, the Czech Republic, Hungary and other newly democratic states have recorded dramatic gains in health. But Ukraine and Belarus, which have followed Russia’s political course of far more restricted freedom, have seen their health measures decline. The Baltic states of Latvia, Lithuania and Estonia, which were once republics of the Soviet Union, at first shared Russia’s downward spiral; but since 1995, as they have built Western-style democracy, they have reversed the trend and now follow Poland’s path.

Here is a comprehensive paper with data and cross-country comparisons. From this excellent piece I learned the following:

1. Health in Belarus has continued to decline. Since Belarus has stayed largely communist, the country may serve as a possible control for where Soviet health was headed before communism fell.

2. In Russia, many of the biggest negative health changes have come for the 18-34 group, not for the elderly.

3. In the CIS countries, injuries and violence account for a quarter of all deaths about men aged 25-64; this is six times higher than the death rate from Western Europe.

4. Homicide and suicide rates in CIS countries exceed those for the West by about 20 times.

5. In Russia, deaths from all external causes correlate closely with deaths from alcohol poisoning.

6. Men of low educational background have been to most vulnerable to bad health.

7. Russian life expectancy has declined but it actually improved during the 1994-8 period and has moved with economic crises.

Here is some additional information on mortality trends in Eastern Europe, here is another related link. Zatonski has a longer essay, which I do not currently have access to.

The bottom line: Here is what I used to think: “I blamed the Russian health collapse on the loss of relative status for the elderly. While market reforms have increased aggregate wealth, this has been mostly for the young. Older people have lost their grip on power, and suffered psychologically through their loss of international relative status as well. They lost the will to live and died early.”

Here is what I now think: “Russian young and middle-aged men have found few useful institutional supports during the transition. They’ve gone crazy with drinking and violence.” That being said, I don’t think we have sorted out the relative importance of economic and political factors.

Teenage pregnancy

Since 1991 the teenage pregnancy rate has fallen by about 22 percent, reversing a 40 year trend. In a lengthy story, the NYTimes suggests that learning from the hard experience of others is the explanation for the drop without explaining why it should take 40 years for this learning to take effect. They do note “teenage pregnancy had already begun its decline in 1991, well before welfare changes and the economic boom, and well after the first round of sex education programs.” The Times, however, does not examine the most controversial but well-supported explanation, the introduction of legalized abortion in the 1970s.

If this explanation rings familiar it should. In a very controversial paper, Steve Levitt and John Donohue provided evidence that legalized abortion in the 1970s reduced crime some 18 years later. The theory is simple. Abortion rates are higher among the poor, the unmarried, teenagers, and African Americans than among other groups and children born to mothers with several of the preceeding characteristics are at increased risk for becoming involved in crime. Legalized abortion gave these mothers an option and thus reduced the number of at-risk children who might otherwise have grown up to become criminals (note that abortion doesn’t mean fewer children per-se, it may simply delay childbearing to when the mother is not poor, a teenager or unmarried which works just as well.)

In brief, the evidence for the Levitt-Donohue theory is a) the timing is consistent, b) states that legalized earlier had earlier drops in crimes, c) there is a dose-response effect i.e. states that had more abortions had bigger drops in crime, d) the drop in crime in the 1990s occured among those cohorts who were potentially affected by abortion policy in the 1970s (and not among say 40 years olds.)

Joined by co-author Jeff Grogger, Levitt and Donohue apply the same idea to teenage pregnancy and find very similar results – thus reinforcing their earlier story. They write:

Parents who are least able or willing to begin caring for a newborn are most likely to make use of abortion. The abortion rates for teens, the unmarried, and the poor are substantially higher than for the general population. Children who are born unwanted are subjected to poorer care both during pregnancy and the early years of life. With the legalization of abortion, mothers with unwanted pregnancies suddenly had a new recourse. Consequently, the number of children raised in adverse environments dropped substantially. Donohue and Levitt [2001] showed how this change reduced crime among the subsequent generation by 15-25 percent. As teen childbearing is a closely associate social pathogen, the magnitude of the drop should be similar.

Our empirical evidence suggests that birth rates as teens are strongly negatively associated with being born in a state and time period in which abortion rates were high. Our results suggest that teen birth rates today may be 20 percent lower as a consequence of legalized abortion in the 1970’s.

Let’s spend more on health care?

That’s what David Cutler argues in his recent book Your Money or Your Life.

Cutler believes that our expenditures on health care have more than justified their cost. He therefore opposes the traditional recipe of “cut costs and use the savings to finance greater access.” His attitude is closer to “expand care now and improve the quality of outcomes.” If you think that more discretionary spending doesn’t make many people much happier, why not make them healthier and longer-lived instead?

As I read the book, Cutler is pushing two major ideas:

1. Subsidize insurance to ease the problems of the forty million uninsured. But he repeats the usual numbers, without convincing me that the problem is as bad as it sounds.

2. Pay for health care results, rather than rewarding expenditures per se. In other words, give doctors and hospitals bonuses for actually making patients better.

A loyal reader of MR should not be surprised to read that Robin Hanson had the idea first. Read his intriguing essay at the link. In Robin’s vision you buy your medical care from an institution that contracts with a third party to pay penalties, or receive bonuses, depending on your longevity, disability, et.c — whatever can be measured. I can imagine such incentive schemes working in the decentralized private sector, especially after much trial and error experimentation. (Note the potential adverse selection problem: you don’t want providers to have an incentive to shun hard-to-improve cases.) It is much harder to see federal or even state governments getting the incentives right, and having the political capital to see the correct decisions through.

The bottom line? Cutler is obviously a smart guy but overall I found the book underargued. I like his optimistic, can-do attitude, but I don’t trust it in the hands of politicians.

Can suicide be rational?

Carolyn G. Heilbrun’s suicide this past October could not have come as a great surprise to her family and friends. After all, the 77-year-old former Columbia University literature professor and mystery author [pen name Amanda Cross] had written for years about her plans to kill herself.

Heilbrun was suffering from none of the conditions commonly associated with suicide when she evidently took an overdose of pills and put a plastic bag over her head. She was neither terminally ill, in severe pain nor, apparently, depressed. Instead, she committed what some have called “rational suicide” — ending one’s life out of a conviction that one has lived long enough, that the likely future holds more pain than joy.

Rational suicide, a coinage dating back nearly a century, has also been called balance-sheet suicide, suggesting that sane individuals can objectively weigh the pros and cons of continued life, and then decide in favor of death.

Read the whole story. (You will note that The Washington Post has new registration procedures, it takes no more than a minute, and we link to them frequently, you are encouraged to register.) Or sometimes you may attempt suicide to get more attention and resources from other people.

I am a skeptic, and unlike many economists I am willing to point The Finger of Irrationality. Consider the following:

Heilbrun’s decision [is] such a disturbing one, says suicide expert John L. McIntosh, chairman of the psychology department at Indiana University South Bend. Even someone making what appears to be a thoroughly rational case for suicide, McIntosh says, can be suffering from depression or cognitive rigidity, an unwillingness to consider other options. Health professionals, he stresses, should be diagnosing and then treating such individuals.

So what happened?

Heilbrun…had been especially open about her plans. In her 1997 book, “The Last Gift of Time,” she described life after age 70 as “dangerous, lest we live past both the right point and our chance to die.”

Two concerns that Heilbrun mentioned were her “inevitable decline” and becoming a burden on others. Her motto, she said, was, “Quit while you’re ahead.” But though she was then 71 years old, Heilbrun chose not to act — not yet. Her sixties, to her surprise, had been a source of astonishing pleasure. She wanted to keep writing, enjoy her family and friends, spend time in a new home and keep certain “promises.”

In the July 2003 issue of the Women’s Review of Books, however, Heilbrun wrote that she feared “living with certainty that there was no further work demanding to be done.” She had consented to life, she stated, “only on the terms of borrowed time.”

On Oct. 9, 2003, Heilbrun was found dead in her New York apartment, having committed suicide. A nearby note read “The journey is over. Love to all.”

My take: I plan on hanging on until the bitter end. Perhaps that is why I cannot so easily imagine a rational suicide, apart from cases of extreme pain and terminal illness.

Medicaid and the High Price of Pharmaceuticals

The price that Medicaid pays for pharmaceuticals is based upon the price in the private market. When Medicaid prescriptions are only a small portion of the total market this works reasonably well at avoiding the twin problems of monopsony (Medicaid pushing prices so low that R&D incentives are curtailed, as has happened in the vaccine market) and monopoly (pharmaceutical firms jacking prices up above fair market value).

But in some areas, Medicaid accounts for a large fraction of the market. The Medicaid share for HIV drugs, for example, is more than 50% and in antipsychotics the Medicaid share is more than 75%! (I have cribbed from this paper by Mark Duggan.) In this situation it makes sense for pharmaceutical companies to raise prices – they lose customers in the private market but this is more than made up for by the increase in prices that they can charge to Medicaid. As a result, average prices for HIV and antipsychotic drugs are higher than for any other drug categories.

The Medicaid pricing formula can create a vicious spiral. Medicaid pricing causes prices to rise which pushes more people into Medicaid thereby shrinking the private market and increasing the incentive to raise prices yet further. To add insult to injury, high pharmaceutical prices are then said to demonstrate why we need more government involvement.

Outsourcing medical experimentation

India is emerging as a new proving ground for pharmaceutical trials. Clinical trials in India typically cost 50% to 60% less than in the United States. The Indian population is genetically diverse, labor costs are much lower, the number of people is large, many Indian hospitals keep good records, and many diseases are prevalent in India. Furthermore many Indians are “drug naive,” meaning that they are not taking other drugs that could influence trial results. The Indian government, however, will not allow testing for basic drug safety, out of fear that Indian nationals would be viewed as “guinea pigs” for the West.

The bottom line: Medical outsourcing will lower drug development costs and save lives.

The full story is from Thursday’s Wall Street Journal, “India Emerges as New Drug Proving Ground,” Marketplace section. Here is an earlier MR post on medical outsourcing.

Kidney swaps

Your spouse is dying of kidney disease. You want to give her one of your kidneys but tests show that it is incompatible with her immune system. Utter anguish and frustration. Is there anything that you can do? Today the answer is yes. Transplant centers are now helping to arrange kidney swaps. You give to the spouse of another donor who gives to your spouse. Pareto would be proud. Even a few three-way swaps have been conducted.

But why stop at three? What about an n-way swap? Let’s add in the possibility of an exchange that raises your spouse on the queue for a cadaveric kidney. And let us also recognize that even if your kidney is compatible with your spouse’s there may be a better match. Is there an allocation system that makes all donors and spouses better off (or at least no worse off) and that maximizes the number of beneficial swaps? In an important paper (Warning! Very technical. Requires NBER subscription.) Alvin Roth and co-authors describe just such a mechanism and show that it could save many lives. Who says efficiency is a pedestrian virtue?

See here for more on how to alleviate the shortage of transplant organs.

When Affirmative Action Kills

The United Network for Organ Sharing says that “justice refers to allocation of organs to those patients in the most immediate need.” As such, skin color should be irrelevant in deciding who gets a transplant. But although proponents are loath to make race an explicit factor in transplant policy they are surreptitiously redesigning the organ allocation system in order to increase the number of blacks who receive transplants. The system is being redesigned to meet the ideals of the social planners despite the fact that such “affirmative action” will result in more deaths overall. As a proponent of financial incentives for organ donors I have often been accused of being immoral. But my conscience is clear – I have never advocated killing people to serve my idea of social justice.

From the Wall Street Journal (Friday, Feb. 6).

New rules for allocating scarce kidneys will result in 6.4% more blacks getting transplants, while slightly increasing the number of unsuccessful transplants, a study finds.

Blacks and other minorities have long been disadvantaged on transplant waiting lists — in part because the scoring system gave strong priority to compatibility between a recipient and the donated organ. Although blacks donate organs as often as whites, they have an extremely wide variety of protein markers on the outside of their cells — making an exact match much harder to find than for whites.

Making matters more acute, kidney disease in blacks is very common, owing to their higher rates of high blood pressure, which takes a toll on the urine-filtering organs. Blacks make up 12% of the U.S. population, but account for 36% of the 56,544 people in the U.S. waiting for a kidney. Prior to the scoring system overhaul, they were 33% less likely to get a kidney than whites.

The new rules, implemented in May by the United Network for Organ Sharing, stop giving priority for a certain type of immunological match known as HLA-B.

The report on the new system, in Thursday’s New England Journal of Medicine, used a statistical method to predict what will happen under the new rules. It finds that, had the new rule been in effect in the year 2000, 2,292 blacks would have gotten kidneys, up 6.4% from the actual number of 2,154 blacks. Meanwhile, 3,954 whites would have gotten the organs, a decrease of 4%. Hispanics would have seen a 4.2% increase. Asians would have seen a 5.9% increase.

Critics feared the new rule could reduce the success rate of transplants, effectively wasting precious organs on people whose bodies were likely to reject them. About 2% more organs will be rejected in people of all races, resulting in the need for another transplant, the study predicts.