Thursday, October 07, 2010

How much basic science do you need to learn in order to be a doctor?

I'm revisiting this topic, which I blogged about a few weeks ago, because it has surfaced again with this post by DB as the jumping off point. It has led to an interesting discussion, so I'll dive in. Again.


Some of the discussion on this topic has centered around whether students need to take organic chemistry, so in my earlier post I said this:


I don't think anyone knows how much basic science preparation is optimal in either medical school or undergrad. Maybe we could do with a little less. Moreover, a better background in the humanities can only be a good thing. (You can still major in the humanities and meet traditional med school basic science requirements, by the way. Generations of med students have done it under the “old” pathway). On the other hand, and this is a purely subjective observation, I wonder whether we are seeing a dumbing down of medical education attributable to a gradual de-emphasis on basic science over the past two decades.

Organic chemistry was a pivotal course for premeds at my undergraduate school. It's one of those courses, at least when taught properly, where you can't get by with rote memorization. Basic concepts and patterns had to be understood and built upon. My professor was passionate in his belief that a fundamental understanding of the human body and the natural world was important for success as a physician.


I got a little flack for those comments. I certainly wasn't trying to make the case that organic chem is essential, or that if you skip it you dumb down your education. I do think it's a good example, because mastery of the subject requires fundamental understanding more than rote memorization. The same is true in the preclinical and clinical sciences. A fundamental understanding of disease is important.


So DB's post refers us to this Lancet article on the subject. The author, Donald Barr, a physician and a medical educator, makes one conclusion I can agree with:


There is a critically important threshold of scientific knowledge that forms the foundation on which a medical education is built.


Of course nobody knows what that threshold is. Research evidence addresses the question but hasn't provided the answer. So we have to be careful how much we devalue basic science.


After relating a story about a promising undergraduate student whose application to medical school was rejected because his science grades were not quite high enough, he notes:


25 years later I began advising undergraduates at Stanford University, many of whom had come to Stanford with the hope of eventually becoming a physician. From many of these students I heard what would become a mantra. “I used to be pre-med, but…” It seemed common knowledge among these students that a C+ in organic chemistry was simply incompatible with hopes of becoming a physician. If you can't do science, you can't succeed as a physician. If all you can pull is a C+ in chemistry, it's unlikely you'll get into medical school. By then I had more than two decades of clinical practice experience to teach me what a great physician was. A great physician creates a bond of communication and trust with his or her patient; a great physician can sense the feelings the patient is struggling to express or afraid to try; a great physician is also technically competent and conversant in medical science. For so many of these students, as for the applicant in the cafeteria, I had a clear, intuitive sense that, given the chance, they would become great as physicians. A quarter of a century after the interview in the cafeteria I had the confidence I was correct. To use a mediocre score in an undergraduate science class to disqualify these students from a medical career seemed indefensible.


I agree with his premise, but are admissions committees really disqualifying applicants with weaker science grades or is it a matter of available slots? I remember my premed advisers telling me that since there were many more applicants than available slots a lot of qualified students would be rejected. I got a few rejection letters that said the same thing.


Dr. Barr goes on to review the history of medical education and some of the research underlying it, citing this speech from 1914:


Addressing the CME in 1914, Dr Victor Vaughan, a founding member of the Council, spoke the core belief on which the American medical profession by then was built.

“No man is fit to study medicine, unless he is acquainted, and pretty thoroughly acquainted, with the fundamental facts in physical, chemical, and biological subjects…The facts of the biological, physical, and chemical sciences are the pabulum on which medicine feeds. Without these sciences, everything that goes under the name of medicine is fraud, sham, and superstition.”

Was there evidence to support Vaughan's words? Is science the pabulum that nurtures young physicians? I went back in the literature of medical education 40 years before the time of Vaughan's comments, and found no scientific evidence to support his assertion.


First, evidence or no evidence, isn't it axiomatic that medicine should be science based? And, as a matter of fact there was compelling evidence to support Vaughan's words. It was in the form of the Flexner Report, a meticulously conducted survey of medical schools in the United States and Canada, published in 1910. It's patently obvious that Vaughan's words echo the concerns of that report, which is why it's astonishing to me that Dr. Barr ignores it.


In the pre-Flexner era medicine, and medical education itself, were indeed based on fraud, sham and superstition, namely homeopathy and other forms of snake oil. The past two decades have seen a gradual de-emphasis on basic science. Maybe that's not entirely bad but is it merely coincidental that pseudoscience and quackery have gained an increasing share of the curriculum at the same time? That acupuncture points and meridians have been introduced into the curriculum for first year medical students? That medical students purport the health benefits of wheatgrass and Voodoo? That promoters of quackery who now lecture med students would have been hooted off the podium 20 years ago? Just asking.


One other point about Barr's article deserves mention. He implies that once you exceed some minimum threshold, further increases in scientific knowledge and aptitude may make for worse physicians. The literature he cites in support of this idea, fascinating though it is, is soft. It's based on surrogate endpoints from psychological testing. Here's what he cites:


Gough reported that students' undergraduate science grades and MCAT science scores were associated with grades in the first 2 years of medical school, but were, “almost completely unrelated to performance in the fourth year and to faculty rating of general and clinical competence”.


That finding is intuitive, and it's easy to understand why. More on that below, but back to Barr's article:


He then compared the psychological profiles of these students with their performance in premedical sciences. He found that the students who did better in science were, “narrower in interests, less adaptable, less articulate, and less comfortable in interpersonal relationships”...

A number of others have found the psychological profile of students who perform best in the premedical sciences to be the reverse of what one might hope for in a physician. Writing in the 1970s, Witkin found students who were most successful in the sciences, “have an impersonal orientation: they are not very interested in others”. Tutton's studies of medical students in Australia in the 1990s found that students who did the best in the premedical sciences scored lower on standardised measures of empathy and tended to be “shy”, “submissive”, “withdrawn”, or “awkward and ill at ease socially”, characteristics the author suggested are, “the antithesis of what most of us would want in a clinician”.


What are we looking at here? Is this a group of kids with high functioning Asberger syndrome? Concerning though the findings are they represent soft data. It's far too big a leap to conclude that excellence in basic science beyond a minimum threshold makes for an inferior physician. In fact, it's a leap into the absurd which is fraught with unintended consequences. If admissions committees wish to take into account non-cognitive attributes of applicants (and I agree they should) there are better and more direct ways to go about it than to devalue excellence in basic science. There are ways this could be addressed during the interview process. I know of at least one state medical school that, after narrowing the initial pool of applicants, gave candidates the MMPI. As extreme as that may seem it's better than devaluing excellent science grades. Besides, I think Barr creates a false dichotomy by implying that one can't be brilliant in the sciences and possess the human attributes that are desirable in a clinician.


DB talks about students who struggle in the basic science years, then do very well on the clinical rotations. It's a common observation. Some students, maybe a smaller number, display the opposite pattern. I was one of them. That's a fact which, I freely admit, may contribute to my bias in this debate. I loved my basic science courses. As third year approached I was eager to apply what I'd learned. I was in for a shock. Putting theory into practice was anything but straightforward. I struggled through most of third year. I finished fourth year doing sub-internships in emergency medicine and my chosen specialty of internal medicine. Thanks to some wonderful residents who mentored me with patience and understanding I finally hit my stride.


So there are two extremes among medical students. Some struggle in the basic sciences and thrive when they hit the wards, while others display the opposite pattern. Both groups have catching up to do. Both can make excellent physicians.

1 comment:

Sahil said...

Thank U Dr. for sharing the basic science notes.Well,can U guide me how to start with the medical school admissions,like what are pre examination preparation ,how to select the med school etc.?