Monday, March 30, 2009

The Banality of Marijuana in Medical Education

In one of our GI lectures, among the interminable pharmacology powerpoint slides that address anti-emetic drugs, the following information appeared:
If an alien guest to our planet perused a pocket pharmacopeia, and had to guess which drug would be "fetishized" over all others, I doubt he'd pick marijuana. Mind you, I'm not convinced that there are many positive benefits for healthy people to take marijuana (and smoking a combustion product is more carcinogenic than using a vaporizer). Yet cannaboids strike me as just another class of drugs with certain indications and side effects, some known, some perhaps unknown. Another anti-vomiting drug, metoclopramide, can lead to tardive dyskinesia (Parkinsonism). Scopalamine, yet another, features a whole slew of anti-cholinergic (antagonistic to the parasympathetic nervous system) effects, and can cause delirium in overdose.

However, when patients with cancer obtain the latter two drugs, we praise modern medicine's ability to provide some alleviation to the horrible side effects of chemotherapy. When patients happen to select the former, we convict their state-law-compliant medical dispensers of crimes punishable by up to 100 years in prison.

Monday, March 23, 2009

Taleb and Pre-test Probabilities


Arnold Kling comments about Russ Roberts' conversation with economist Nassim Taleb:

I was most interested in the latter third of the conversation, where Taleb talks about his radical empiricism. For example, he argues that medicine makes more progress with trial-and-error than with knowledge of biological processes.


Trial and error would require taking a drug already known to be ineffective, adding a methyl group, testing the new molecule on a statistically significant number of patients, and then methylating again, until we've tested infinite permutations of "little-value-added" functional groups. We'd be bored sick.

One of the reasons why many empiricists object to all the funding that goes into certain alternative medicine projects, such as magnet therapy or reiki, is that, based on our understanding of physiological or biochemical principles, the pre-test probability of such treatments being effective is pretty low. An extreme Popperian would object, insisting that we can't truly know if anything works, before testing it, (and once experiment concludes, we still couldn't be sure). Such agents of uncertainty would be technically correct.

However, science does not mean claiming omniscience nor capitulating to any smidgen of doubt. Science involves taking the information that lies before us, determining what phenomenon is most likely, and using these findings to develop a testable hypothesis. We are occasionally lucky enough to discover a drug whose mechanism of action we do not fully understand (such as in the case of Topirimate for epilepsy, or the prevalent use of beta-blockers of hypertension, long before we knew how it worked). Yet relying on lucky breaks, or "trial and error," rather than "hot on the trail" paths gleaned from discoveries in biology, is like searching for a bank robber by starting with the As in the phone book. Or like seeking out a black swan, by beginning the expedition at a local Los Angeles lake.

Thursday, March 19, 2009

Med Students Lobby Congress for Tuition Breaks

People, I know that we aspiring physicians are all in major debt, but some Americans can't afford the rent for their trailer homes. Let's leave the welfare-for-the-well-to-do-groveling to the AIG execs.

Ross Douthat is Trying to Murder Michael Kinsley! (Or Some other Distortion of Douthat's Views)

Brad Delong links to "The Daily Beast" and writes:
Michael Kinsley confronts the fact that Ross Douthat doesn't care more than a smidgeon about whether Kinsley lives or dies from Parkinson's disease.

If Kinsley were facing imminent death, and the only guaranteed antidote was a destroyed embryonic stem cell, I'm sure Douthat would fly over in a crimson-colored-cape and perform the destruction necessary to save the day. The fact that Douthat opposes federal funding for promising basic science research, that may one day be used treat PD, is far removed from the notion that Douthat doesn't care whether Kinsley lives or dies. If all of us were certain that could automatically save a life by sponsoring a certain magnitude of stem cell research, most of us would wire donations overnight. We don't do this, and thus admit that Kinsley's life is not immediately and urgently dependent on it. Reducing the situation to two variables (Kinsley's life versus stem cell funding), as well as admitting no degree of uncertainty about the potential effects of both the research and its related public policies, is innacurately simplistic.

Ok, I stood up for the social conservative.

Now, let's get the pluripotent blastocyst-derived inner cell mass differentiation party started!

Update: Before writing this post, I had written the first paragraph, as a comment in Brad Delong's blog (it did not include the more bellicose title of this post). It was taken down, after a few hours. Brad Delong has the right to do whatever he wants on his blog. However, I am disappointed by an academic who is unwilling to tolerate reasonably polite critique.

Wednesday, March 18, 2009

Who Lives?


Mr. Smith is a 58-year-old African-American male, who appears at least a decade older than his stated age. He is about 6’0, slim, and features a neatly-trimmed mustache. He sits stooped forward, and relies on a cane to get around. Mr. Smith has a pleasant affect, and even offers to get me a cup of water. His legs show moderate edema, and his eyes feature notable scleral icterus. Mr. Smith is on the list.
Mr. Smith inquires to whether I’m “also on dialysis,” and if I voted for Obama. I told him that I’m attending as a medical student, and that I don’t share my political views in public. Mr. Smith believes that Obama will bring us “back to nature” and will stop “sending jobs overseas.” I smile and tell Mr. Smith that I hope the president helps solve the economic crisis. This is no occasion for pessimism.

Mr. Smith expounds on his dating woes. His last girlfriend was “too needy,” and wanted something more permanent than Mr. Smith was able to provide. Mr. Smith implies that his misgivings were more due to his lack of emotional readiness, rather than the fact that his remaining days are contingent on a fluctuating number on a table, and that, like many of the 101,236 current Americans waiting for an organ, he may die before receiving a much-needed kidney transplant.

I met Mr. Smith, because I happened to sit next to him this past Sunday in a downtown Los Angeles theater, to view “Who Lives?,” a play Sponsored by the Renal Support Network. The production takes place in early 1960s Seattle, and explores the moral anguish afflicting a committee dedicated to choosing the lucky few who will test a curious, but experimentally promising machine, which “removes your blood, cleans it out, and then returns it to your body.”

The panel consists of a devout priest (“God has chosen us for this very important purpose”), an overwhelmed homemaker (“Father, there isn’t anything spiritual about this!”), a blue-collar craftsman (“The workers are always getting a raw deal, so what’s so wrong…”), a pedantic, neophyte doctor (“Disease is just the gross exaggeration of aging”), a pushy Jewish lawyer (“F-ck doctors”), a beautiful, liberated grad student, and some un-endearing blonde guy, who instinctually rejects Black applicants, and focuses the rest of his attention on seducing the grad-student. The group’s task involves ranking people, not merely based on medical criteria, but also each applicant’s presumed “value” to society. Thus, the committee debates the relative "significance" of musicians versus businessmen. The wealthy versus the poor versus the “rags to riches” success stories. Women versus men. Women with children versus men. Fertile women versus infertile women versus men. Blacks versus whites.

Today, such technocratic management of life and death strikes one as pretty abhorrent. Unfortunately, however, I find no solace in our contemporary method of organ allocation. Indeed, while we, as a society, have come to recognize the human infallibility inherent in prioritizing human lives, we now do something far worse, by creating an artificial shortage of life-saving organs, and banning individuals, charities, and the government from paying people for their kidneys.

We invoke all kinds of moral arguments to dissect messy commerce and greed from the prim and genteel art of uprooting a meat-sized slab of tissue, hitching it to various tubes and plumbing out a urine stream. To defend the volunteer-only status of organ donation, liberals and conservatives alike manufacture arguments that they would never entertain, when concerning other topics: “The poor will be the first to give up their organs, and this is harmful!!” (Cs: Should we prevent the needy from obtaining payday loans or eating at McDonald’s? Ls: Ought we to restrict women from obtaining abortion or birth control, even if it posed her some risk?) “It will be racist!” (Check out the demographic makeup of the waiting list.) “It will cheapen the ideal of giving from the goodness of one’s heart! “ (Ls: Do you ascribe the same logic to food stamps? More ceremoniously- “Would you like to sign up today and volunteer to save a life?! Low risk and high 'goodness of heart' satisfaction! No? I, shamefully, haven't signed up either...”) “Legalization will increase violence and coercion!” (Organ prohibition, meet drug prohibition), “Only rich people will be able afford them!” (Rich medical tourists and insurance-holders are generally the only ones who can afford obtaining organ transplants. If legalized, there may still be a disparity between the rich and poor in organ procurement, just as there is in all aspects of medicine, but this does not call for a ban on all medical procedures. However, we can legalize organ sales, and then- depending on whether you favor Heritage or TAP- accept a certain degree of inequality, or fiddle with our health care system, so that the poor can afford organs, as well).

My feeling is that most people oppose economic exchange of organs simply because the whole idea seems very, very unpleasant (yes, to me, too!). But good public policy is not constructed to convenience such a persnickety relic of natural selection as our sense of disgust. We ought to focus solely on whether we are actually helping people like Mr. Smith, who needs additional time to find the fellow freewheeling partner of his dreams.

In “Who Lives?,” while the committee pores over endless piles of pallid folders, the delicate housewife cries out, “We shouldn’t even have the power to make this decision!” However, she and her colleagues at least brave the clearly-understood ramifications of crafting countless letters featuring the dreaded words, “We regret to inform you...” Today, meanwhile, we largely avoid such formalities, by revering our high-minded legal dictates, and remaining casually inattentive to the tragic reality of thousands of end-stage kidneys.

Friday, March 13, 2009

Judging Others

At Overcoming Bias, Robin Hanson states:

When evaluating someone intellectually, I tend to downplay their degrees, publications, affiliations, etc. and focus on how they handle themselves in intellectual conversation. But most academics have more prudish norms, and consider it rude to challenge prestigious visitors to thoughtfully discuss topics beyond their prepared speech. Thank goodness my favorite lunch partners share my imprudish tastes. :)


I wonder if his method of evaluating intellectual ability may introduce more bias than does checking out the speaker's degrees.

If someone has a fancy education or job, she demonstrates that she was at least able to accomplish something minimally substantial over time (except in rare cases). If you judge someone based on a single conversation, well- What if he was nervous? Sick that day? Expresses himself better through writing than via speech?

I'm still working out my general approach to judging others. Which is the most fair (and possible) strategy: Matthew 7:1 , Pirkei Avot 1:6, or regularly scheduled Bayesian Updates?

Wednesday, March 11, 2009

Show Your (Well, Other People's) Work!

Olivia Judson's fabulous blog for the New York Times leads me to wonder:
Why aren't all journalists required to cite their references?