I began reading Glew's article  with some trepidation. I thought I was in for another tedious evidence-based meta-analysis comparing apples and oranges to turnips and watercress using fancy statistics to come to essentially pointless conclusions. I was pleasantly surprised to find a superbly written, carefully constructed, thoughtful piece that echoed much of my sentiments.
I prefer to state my biases clearly so that readers can stop reading straight away. Active learning is preferable to passive learning. The format is less important than the intent. Biological sciences have a strong experimental component. The ideal curriculum in basic sciences would be entirely lab-based. Since that is rarely possible, we need to consider the next best options (or NBOs in the current vein of acronym coinage). Of those, problem-based learning (PBL)11 holds much promise. Shorn of all rhetoric, it is an approach that starts with an unclear situation (scenario, problem, data) and requires students to generate learning tasks. Small groups are not strictly needed, although they are quite convenient. Essentially it attempts to shift the locus of control from teacher to student.
When I came to McMaster University on a research scholarship from the Canadian Heart Foundation in 1981, I had never heard of PBL and had little or no interest in teaching. In fact between the time I started my Ph.D. and joining the Faculty at McMaster (a span of 16 years), the total time I had spent in formal teaching was less than a few months. Fortunately that lack was not an issue in my recruitment. When I first heard of PBL, I thought it was quite ludicrous. The emphasis on process rather than content seemed downright silly. One could churn out doctors after having them consider the treatment of hemorrhoids in a hippopotamus. However, my views changed quiet drastically when I saw PBL in practice. I sat in on a tutorial group, conducted by my former Ph.D. supervisor, E. E. Daniel. He had actually told me not to discount anything without testing it. I watched in amazement as I saw 2nd-year students discussing fairly sophisticated concepts in pharmacology with aplomb, having had no lectures or labs at all. That experience got me rethinking. I realized that when I was a medical student, I had practiced a similar approach, bunked classes, and studied either on my own or with my friends. Thus the McMaster approach merely legitimized standard normal medical student behavior.
Since 1983, I have been involved in PBL in a variety of settings. These have included tutoring in an undergraduate Honours Biology-Pharmacology Co-op Programme, a liberal arts course, an undergraduate toxicology course, and a graduate course in Physiology-Pharmacology as well as in the medical school. My visions of the promises and pitfalls of PBL have been colored by all those experiences. I see the excitement that active engaged students can bring to their learning in almost all those experiences, but sadly it is my involvement with the medical program that has made me painfully aware of the pitfalls of PBL and for much the same reasons highlighted in the article.
Glew notes that an extensive literature seems to show that the PBL approach has worked in many educational settings and wonders whether there is something different about medical schools. Since he states that he does not reject PBL, I believe that he is concerned about the implementation issue. No education system functions in a vacuum, least of all one that is relatively resource-intensive. The author quite rightly suggests that the blame can be shared between the clinical faculty, the basic scientists, and the administrators.
The temper of the times places clinicians under pressure. Despite the impression south of the border that we have rampant socialized medicine out here our clinicians are under similar pressures. Balancing clinical service, research, and teaching is not easy. Yet a number of clinicians do work hard at “being busy.” Somehow they are never too busy to turn down invitations to attend industry-sponsored conferences (coyly called “educational events”) at pleasant spots. If tutorials could be organized in airport lounges or in holiday resorts, our students might actually get some attention from these very “busy” people. When I was co-chairing one of the Units in the M.D. program, some 15 years ago, I found it difficult to gather quality tutors for a 16-week block. It has become far worse now. Glew is quite scathing about the notion of clinician educators, and he may have a point. However, I know of very dedicated clinicians at our medical school who do yeoman service on behalf of the students. Unfortunately they are a precious few.
The basic scientists are not blameless either. The author notes that by and large these people have not bought into the PBL system. I know of medical schools where basic scientists have adopted just that position. They tend to treat PBL sessions as a bit of a joke (not worth their attention). The situation at McMaster is a bit mixed. A number of basic scientists (me included) continue to participate in the undergraduate medical program. Some have been in leadership roles for many years. However, there are others who prefer to tutor in undergraduate science programs where PBL plays a significant role. In part this stems from the disenfranchisement mentioned by Glew. It is definitely more rewarding to deal with students who share one's enthusiasm for a subject rather than with those who either require that information to merely pass an exam or as a means to some other end.
The issue of teaching basic sciences in a PBL-based medical program is a thorny one. Although the concepts underlying PBL are really quite old, the modern version was largely created in the medical program at McMaster University. One of the central issues that the “founding fathers” grappled with was how to incorporate basic sciences in a meaningful way. Steering a course between the Scylla of pedantry and the Charybidis of puerility is very, very difficult. No wonder very few institutions have gotten it right. I have argued elsewhere for the creation of a “non-embarrassing” curriculum . This is one that includes items of information so basic and general that a lack of awareness or appreciation would produce a physician who would be an embarrassment to the program. I am particularly concerned that students should appreciate fundamental principles that apply to living organisms. Glew mentions that students are unable to reason their way through problems based on basic principles, and he is unfortunately right. But the root of this malady is not just PBL but something more insidious and much worse, the newest buzz word to emerge from my institution, evidence-based medicine (EBM).
In principle, there is really nothing wrong with EBM, although I feel it is a trifle arrogant to assume that all other systems of medicine are not based on evidence. However, in practice, the devotees adopt an empirical, outcome-based approach that relies heavily on randomized controlled clinical trials (RCTs) as the fount of all wisdom. I hasten to add that the gurus of EBM are not so doctrinaire, but unfortunately their acolytes are. A few months ago, I gave a talk to residents in Family Medicine about drug metabolism. I casually asked them what they thought about anecdotal evidence. They sniggered. Whereupon I asked them what they did when they took a history from a patient. Did they send the patient away till they had gathered 10 such histories before they took action? Unfortunately reliance on RCTs makes life much easier since one can quite conveniently practice algorithmic based medicine (ABM) without understanding much. Given this climate, getting more basic scientists involved will not change the picture, it would just make it worse. Students will dismiss their contributions simply because they do not see patients and therefore do not know what they are talking about. In this they are often aided and abetted by their clinical mentors. Only a few weeks ago I heard one student complain that she got very little out of her tutor because he was a Ph.D. This cultural divide makes matters worse.
Glew notes that basic scientists express anger at the curriculum having been hijacked by the clinicians. Most students enter medical school not to patch clamp cells or to tease out transduction mechanisms but to diagnose and treat patients. Their goals are very, very different. It is the task of the basic scientist to help them attain sufficient understanding so that they can achieve that aim. There is no reason why they cannot rise to that challenge. Several years ago I was asked to tutor a unit in a Physiotherapy program. I was quite familiar with the content of that unit (cardiovascular and pulmonary function) but had no inkling as to what was required of a practitioner. So I spent some time reading texts and talking to physiotherapists to get some understanding of their needs. The experience was quite exhilarating. The students appreciated the efforts I made on their behalf, and I, in turn, learned to “apply” my knowledge in a different domain. It gave me a better appreciation of physiology. Glew suggests basic scientist-clinician pairs to promote better integration. This is a fine idea. For several years, I tutored with a pediatrician in a unit that emphasized clinical problems through the life cycle. The experience was very rewarding not only for both of us but also for the students. Currently I am co-chairing a unit along with a specialist in family medicine that emphasizes the dimensions of professional practice. Students are expected to deal with a variety of issues ranging from health economics, policy decisions, and media relations to medical mistakes and professional autonomy. There really is no reason that basic scientists should seclude themselves from such matters.
A fundamental change in attitudes is needed. Basic scientists should recognize the needs of medical students. They should realize that students are not ignorant or stupid merely because they seem quite uninterested in alternate splicing of prostaglandin E receptors or in the intricacies of inverse agonism. Clinicians should realize that they ignore fundamental sciences at their own peril. Excessive reliance on empirically derived outcome measures is problematic. Without an understanding of pathophysiology, decisions based on such measures are not much better than those based on horoscopes. To state that studies indicating that 22 ± 3% of patients of a certain age and sex respond to a specific drug in a particular way (without knowing why or even attempting to find out) is really no different from saying that someone born under the sign of Jupiter better avoid drugs in a particular week. Simply because a number is added to a statement does not make it any less vacuous. The public has easy access to the same empirical information that doctors have via the Internet. They too can practice ABM. The least that they can demand of their doctors is greater understanding of the reasons why. That understanding cannot come without the help of the fundamental sciences. Thus, for the full potential of PBL to be realized in a medical program, basic scientists should get off their high horses and deal with the needs of students, and clinicians should recognize that without basic sciences they are merely astrologers and necromancers. If this cultural divide is not breached, the promises of PBL will remain unkept.