29 December 2011

Is it a boy? The foreseeable bad consequences of medical advances

There is a healthy debate over whether a lab that created an extremely infectious version of influenza ought to publish the genetic sequence. The debate speaks to a larger problem: sometimes, medical advances do the world a disservice. The medical field could use some soul-searching, just as physicists did in the wake of the Manhattan Project.

A few years ago, I read a neat research finding: in a pregnant woman, some of the fetus's DNA crosses the placenta and circulates in the mother's bloodstream. Drawing on this finding, some researchers developed a clever blood test that is allowing pregnant women to non-invasively screen their fetuses for Down Syndrome (whereas in the past, amniocentesis or chorionic villus sampling were the definitive screens). Good on them.

Yet other researchers have done gone a step further, offering both maternal blood tests and a maternal urine test that reveals a fetus's gender. One of these researchers, Prof. Diana Bianchi of Tufts University, justifies her development of a blood test because it will help mothers receive early warning about whether their children are at risk for genetic, sex-linked conditions such as hemophilia and congential adrenal hyperplasia.

This benefit strikes me as far too small relative to the tests' tremendous downside: it will greatly worsen the calamitous global phenomenon of the Missing Women.

The expected sex ratio at birth is 105 boys born for every 100 girls, or 1.05. Yet in some countries, the sex ratio at birth is quite skewed: for example, China's is 1.13 and Vietnam's is 1.12. What results is a demographic disaster, with over 100 million women missing worldwide (and a number of unhappy single men left in their wake). This glut of unmarried men may even contribute to global unrest, as unmarried men are more likely than married men to engage in armed conflict or become terrorists.

A renowned economist, Amartya Sen, established that cultural bias against women underlies the deficit. In countries where it is economically advantageous to have a boy, some families murder or neglect their infant girls or abort their female fetuses. Currently, ultrasonography is the only non-invasive way to determine the gender of a fetus. Some of the affected countries have forbidden ultrasound clinics from revealing a fetus's gender, and some intermittently crack down on those profitable yet illicit ultrasound clinics that flout the rules.

But a maternal blood test or urine test will prove impossible to regulate. Making it easier for mothers to determine gender will almost certainly lead to more female fetuses being aborted worldwide, with all of its concomitant problems. I would at the very least like to see a fraction of the proceeds for this blood test go to empowering women in affected countries (by boosting primary education and decreasing maternal and infant mortality), which would begin to help the problem. I doubt we will see it.

Some medical disasters are not easily foreseeable. For example, most leading orthopedists did not expect metal-on-metal hip replacements to become a massive fiasco. Yet developing a maternal blood test for fetal gender has so little justification and its ramifications are so potentially terrible that I believe its developers acted unethically. It's a shame that some scientific advances leave the world worse off than before, because I believe that scientific inquiry possesses a unique ability to make the world rather wonderful.

26 December 2011

'Mindless Eating', by Brian Wansink

Brian Wansink is a researcher whose creative studies ask: why do we eat the way that we do? He finds that our decisions into eating rely much more on external cues (the shape of the glass that holds our orange juice, how quickly others are eating, whether we are watching TV) than on things like how hungry we are.

The way Wansink peers into the psyche of eating is entertaining. In one study, he served some restaurant-goers tomato soup in a bowl that was secretly connected to a hose. As the subjects chowed down, the hose constantly refilled the bowl. He found that the subjects had to eat much more soup than the controls in order to feel full. The lesson? Visual cues can dictate how much we actually eat.

His book, "Mindless Eating," was a delight to read and is geared towards the general public. Although I was more interested in the experiments themselves (scientist as I am), Wansink uses the lessons from his studies to recommend strategies beyond traditional diets for people to take charge of their nutrition and lose weight.

I strongly recommend it, especially for those interested in public nutrition and their own diet.

22 December 2011

Mercury news

Echoing Paul Krugman, I want to point out how huge a deal it is that President Obama and the EPA have issued new national standards limiting heavy-metal emissions from power plants. From the EPA's press release yesterday:
The U.S. Environmental Protection Agency (EPA) has issued the Mercury and Air Toxics Standards, the first national standards to protect American families from power plant emissions of mercury and toxic air pollution like arsenic, acid gas, nickel, selenium, and cyanide. The standards will slash emissions of these dangerous pollutants by relying on widely available, proven pollution controls that are already in use at more than half of the nation’s coal-fired power plants. 
EPA estimates that the new safeguards will prevent as many as 11,000 premature deaths and 4,700 heart attacks a year. The standards will also help America’s children grow up healthier – preventing 130,000 cases of childhood asthma symptoms and about 6,300 fewer cases of acute bronchitis among children each year. [emphasis mine]
11,000 premature deaths per year is a big number. By comparison, the CDC attributes 42,000 deaths annually to "motor-vehicle traffic" accidents. The September 11 terrorist attacks caused just under 3,000 premature deaths, once. And mercury is scary stuff. It tends to accumulate in large fish and in mammals that sit atop the food chain. Pregnant women are discouraged from eating certain types of fish (including albacore tuna) because ingesting the amount of mercury they contain can cause birth defects.

As hard as my classmates and I will try to take care of our patients as physicians, what we can accomplish as individuals cannot come close to the impact of prudent regulations such as this. Bear in mind too that some of the energy sector lobbied hard to prevent these standards from being issued. Good on the Obama administration for protecting the environment and bettering human lives.

18 December 2011

How we learn

I worry somewhat that learning for learning's sake can be a liability in medical school. Perhaps out of necessity, my class devotes the bulk of its energy to excelling on exams. Sometimes this drive to perform runs counter to learning: one of the most effective study tools is to obtain old copies of quizzes and exams. One can do quite well by memorizing the answers to questions that historically appear on exams, even without understanding quite what they mean. Another winning strategy is to come up with mnemonics particular to the examination ("The four arteries we were supposed to remember begin with the letters MIDS").

It makes sense why some classmates would opt to limit their studying to what will be assessed on exams and boards. Many have girlfriends, boyfriends, spouses, and children that (deservedly) compete for their energy and time. Getting top marks in courses yields academic distinction and hefty scholarships. Even our class's lingo revolves around the test: topics likely to appear on an exam are termed "high-yield." Wasting classmates' time with "low-yield" topics is a cardinal sin. Few students read the assigned textbooks, because the exam material derives from the bolded bullet points in our lectures' PowerPoint slides. We were told ahead of time exactly which physical examination methods we needed to know on the final exam; others were summarily ignored.

Even the boards that we take second year (the standardized examination that all allopathic medical students take, and that plays heavily into residency placements) promote shortcuts. If a question begins: "A 19-year old female sex worker comes into your clinic," I instantly know that the answer they will want me to put is a type of STI. Real life is not so simple. Clinical decisions do not involve choosing the best answer of the five choices proferred.

The fundamental question is: should we consider medical school an educational experience in its own right? Or should we treat it as a stepping-stone to our desired residency and career? I fear that learning to the test prevents us from becoming that breed of excellent physician that inspired me to enter the profession.

'Smallpox: The Death of a Disease', by D.A. Henderson

D.A. Henderson led the WHO office that coordinated the global smallpox eradication effort. His 2009 book focuses on the bureaucratic and diplomatic challenges that he and his shoestring staff had to overcome to combat the disease. He gives of an overview of how eradication unfolded in each of the endemic countries, including Bangladesh, which was torn by civil war, and Ethiopia, which had poor infrastructure and a substantial population of nomads. Despite seemingly insurmountable challenges, even the poorest countries accomplished this extraordinary public health feat. Young health care professionals bounding with creativity and ingenuity ultimately prevailed. Henderson also discusses the evolving debate over whether to destroy the remaining stockpiles of smallpox, as well as the threat of a bioterrorism attack involving smallpox. Henderson's work propelled him to a distinguished career as dean of the Johns Hopkins School of Public Health and as a senior White House administrator.

"Smallpox: The Death of a Disease" is a more academic and bird's-eye view of smallpox eradication than is William Foege's "House on Fire: The Fight to Eradicate Smallpox" (which I reviewed earlier). I would recommend first reading "House on Fire." If you find that book particularly stimulating, you will likely enjoy Henderson's book, as I did.

17 December 2011

'House on Fire: The Fight to Eradicate Smallpox', by William Foege

William Foege, a physician who went on to become Director of the Centers for Disease Control, recently wrote memoirs of his experiences leading the smallpox eradication efforts in Nigeria and India. Foege pioneered the successful "surveillance and containment" eradication strategy, which let health teams avoid vaccinating the entire population. Instead, dedicated search teams located infections, and containment teams vaccinated those cities that were sites of outbreaks. Using this method, smallpox was eradicated worldwide in the 1970's. Interestingly, eradication saved the U.S. a substantial amount of money--what it spent on smallpox eradication was only a fraction of what it spent each year on domestic vaccination and on verifying that travelers to the U.S. were immune. It's important to note the debt owed to many countries, including the U.S.S.R., which first championed global eradication and donated a tremendous amount of vaccine.

Given how deadly, disfiguring, and persistent smallpox was worldwide, its eradication is perhaps the proudest accomplishment of global public health. Foege's account illustrates how this monumental effort succeeded only because of scrupulous planning, careful research, a shared vision among health workers, and several strokes of good luck. He writes of his experiences in Nigeria, where civil war broke out, and in India, the leaders of which were largely skeptical of eradication.

I found the book fascinating, insightful, and brief. I strongly recommend it to those interested in public health, health systems management, and infectious disease.

16 December 2011

Why policy matters

You may have read that the U.S. is mired in a shortage of many common generic drugs. Many important chemotherapy drugs are in such short supply that patients cannot complete their cancer treatments, or are being switched to less appropriate or more expensive treatments. Some drug trials have been suspended because the control group is not able to receive the standard of care.

The severity of the shortage is startling. It also deserves some introspection. Our government spends a tremendous amount on researching new drugs (the NIH estimates that it alone spends $31.2 billion annually on medical research). Why aren't we devoting more of our efforts to manufacturing and delivering those inexpensive drugs that we already know to be effective?

Better policies could have prevented such a shortage. Part of the problem seems to be that Medicare is required to pay such low prices for generic drugs that there is little profit margin for manufacturers, and thus, little incentive to invest in maintaining factories and in keeping up production. If Congress were to nudge the reimbursement rate for generic drugs slightly upwards, Medicare would probably save money overall by avoiding expensive shortages. There also may be something more insidious going on, in which manufacturers and middlemen find it profitable to limit supply and thus drive up prices (much like Enron did with California's electrical supply in 2000 and 2001). The government could also develop stronger penalties if drug manufacturers fail to fulfill their contracts to supply drugs to federal health entities (such as the VA and the Indian Health Service).

Medicine does not occur in a vacuum, and this shortage should be another wake-up call that it behooves doctors and patients to understand more broadly what impacts our nation's health and medical care. After all, any of us may become the patients so desperately needing these drugs.

14 December 2011

A milestone

I have successfully completed my first semester of medical school. This means that I am approximately a tenth of the way towards receiving a license to practice medicine (four years of medical school and a subsequent year of internship). I have learned much, yet I feel like I know only the tiniest fraction of what a good physician ought to.

Next semester we will begin studying the ways the body becomes diseased and the treatments for those illnesses. I wonder, after completing my next final exams in six months, how much closer I'll feel to being a doctor.

02 December 2011


Sir Ernest Shackleton, the famed Antarctic explorer, climbed in 1915 across then-unexplored South Georgia Island with two members of his shipwrecked expedition. Famished, freezing, thirsty, exhausted, and underequipped, their desperate journey was their last hope of reaching civilization (in the form of a whaling station on the other side of the ice-encrusted, mountainous island). There, they hoped to inform the outside world of their comrades who were stranded on Antarctica and needing a rescue.

In his excellent memoir, South, Shackleton recalled his perception of someone accompanying the men during their harrowing tramp:
I know that during that long and racking march of thirty-six hours over the unnamed mountains and glaciers of South Georgia it seemed to me often that we were four, not three. I said nothing to my companions on the point, but afterwards Worsley said to me, "Boss, I had a curious feeling on the march that there was another person with us." Crean confessed to the same idea. One feels "the dearth of human words, the roughness of mortal speech" in trying to describe things intangible.

Tonight, I was drawing a schematic of a left-to-right ventricular shunt (a type of heart defect) while working out a tough physiology problem. Staring back at me was a smiling Picasso-esque human face, accompanying me as I studied into the wee hours of the night:

I always dreamed of emulating a bold adventurer like Shackleton. Unfortunately, passing my medical school courses lacks the heroics of Shackleton's escape from the Antarctic ice and the eventual rescue of his entire expedition. At least I can dream up some parallels and pretend.

01 December 2011


The blog will wind down for the next couple of weeks because of our upcoming comprehensive final exams. The amount of material we're responsible for feels staggering. I have never studied this hard in my life. But in going over all that we've learned, I've been delighted to see just how far we have come. I know tremendously more about the human body than I did four months ago. I'm eager to discover what the next few years will hold.