One hundred years ago, authors of an essay on issues in medical education would have been influenced by the health care model predominant at the time, a model characterized by the doctor—patient relationship functioning independently of the context within which underlying problems of illness or injury arose. Moreover, in that era of horse-drawn carriages, social prohibitions on tobacco use by women, and limited life expectancy, the authors would not have foreseen the dominant health problems of the century's end—such as injuries from motor vehicles, deaths due to lung and other cancers, and morbidity from cardiovascular diseases.1 Nor could medical schools or educators have anticipated the quantum discoveries in scientific knowledge that would revolutionize the medical curriculum, requiring instruction in then-unimaginable topics such as molecular genetics and cellular neurobiology. In addition, in 1900, quantitative approaches such as Bayesian analyses, epidemiology, and decision analyses were not seen as relevant to medical practice. But today, these and related topics are vital in medical practice, yet not given their due in medical education. In this Commentary, we review the rationale for strengthening the teaching of epidemiology and other quantitative skills in medical schools, and offer suggestions for overcoming barriers to doing so.
WHY ARE QUANTITATIVE SKILLS NEEDED NOW?
What have the last century's changes meant for medical education? First, in addition to advances in individualized treatment, interventions for the major problems of the 21st century rely heavily upon distinct strategies the physician can use to influence the individual patient's behavior (e.g., smoking cessation, weight loss, and reduction of alcohol consumption), and those that represent effective interventions at the population level. Second, for philosophical, conceptual, and practical reasons, clinicians must pay increasing attention to prevention and related tools for prevention, in part as a function of the managed care environment. With recent changes in health care delivery that have placed new emphasis on the evaluation of physicians' practices, physicians must become familiar with quantitative principles of evaluating health care delivery and outcomes at the population level.
In addition to the effects of managed care on clinical practice, the proliferation of public information sources may have served to complicate medical decision making. One hundred years ago, the patient deferred totally to the physician's judgment and expertise; in 2001, a patient comes to the doctor already exposed to information about specific health problems gained from a variety of sources, including checkout-counter health magazines, nightly television news specials reported by a station's health “expert,” advertising of prescription medications directly to the public, and myriad Internet sites. This explosion of consumer-directed health information—largely not subjected to rigorous peer review—mandates that physicians be able to quantitatively assess evidence from all sources and be able to communicate the validity and limitations of reports, as well as their patients' levels of risk.
The past century of radical change mandates a shift in the emphasis given in medical education to quantitative decision-making skills. As important as it has been to incorporate technologic advances in biosciences in the medical school curriculum, it is equally important to equip students with an understanding of population-based health and skills to use the tools of quantitative decision making.
THE IMPORTANCE OF QUANTITATIVE CURRICULUM
This need was noted as early as three decades ago, when Kerr White, then professor of medical care and hospitals at Johns Hopkins University, lamented the failure of medical education to “embrace epidemiology as the primary scientific discipline with which to build a body of knowledge and principles.”2 One decade later, the renowned medical and public health educator Abraham Lillienfeld argued that universities should establish departments of epidemiology to teach this subject to undergraduates.3 Although the importance of teaching epidemiology in medical schools seems beyond question, little has changed since White and Lillienfeld made their case. Medical educators continue to lament the challenges to incorporating epidemiology into the mainstream of medical education,4 even though some experts have made explicit recommendations to medical schools to include epidemiology as a requirement for undergraduate medical education.5
Epidemiology is the basic discipline for studying the occurrence and distribution of diseases and health conditions in populations and elucidating the factors involved. In the context of medical education, quantitative population-based methods have been considered traditionally in terms of clinical epidemiology, which can be defined as “the application by a physician who provides direct patient care, of epidemiologic and biometric methods to the study of diagnostic and therapeutic processes in order to effect an improvement in health,” or the conduct of an epidemiologic study in a clinical setting.6 However, as applied in public health, epidemiology is much more than this. Epidemiologic methods have been the foundation for major gains in life expectancy and health during the past two centuries.
Epidemiology provides the foundation for the quantitative and critical reasoning skills now demanded of graduates of medical schools and other allied health sciences programs. At the level of the physician's responsibility to the community's health, epidemiology provides a basis not only for participation in population-based approaches to health care, but also for carrying out the practitioner's more traditional public health functions, such as recognizing clusters of unusual conditions or reporting outbreaks of infectious diseases in the practitioner's community. In many settings the modern practice of epidemiology is carried out using other critical reasoning skills, including, for example, statistics, economics, and decision analysis.
CURRENT STANDARDS FOR QUANTITATIVE INSTRUCTION
The need to include training in quantitative, population-based methods in medical schools has been acknowledged, at least implicitly, by the Liaison Committee for Medical Education (LCME). One LCME general standard is that a medical faculty should devise a curriculum that permits the student “to acquire skills of critical judgment based on evidence and experience, and to develop an ability to use principles and skills wisely in solving problems of health and disease.”7 That the LCME has made such a statement is consistent with recommendations generated by many medical education reform initiatives and with those promulgated in 1998 by the Medical School Objectives Project (MSOP), whose goals included the defining of learning objectives by experts convened by the Association of American Medical Colleges (AAMC).5 The MSOP's second report specifically called for medical schools to require that graduates demonstrate knowledge of epidemiology.
In spite of this recognized need for training in quantitative skills, evidence suggests that such course offerings are limited in medical school curricula. The LCME maintains a database of all curricula of accredited institutions in the United States and Canada. Information reported by 125 U.S. institutions for 1998–99 indicates that although most accredited medical schools (92%) reported covering epidemiology as part of some educational experience, only 33% reported dedicating an entire required course to this subject. In contrast, 100% reported requiring dedicated courses for foundational subjects such as anatomy, physiology, and pharmacology.8
WHAT CAN BE DONE?
Given the strong justification for inclusion of quantitative methods in the medical school curriculum, why is the topic not more widely included? One of the most important barriers is the prevalent misconception about the meaning or relevance of population-based methods to medical education, as well as lack of trained staff to teach the discipline and lack of readily accessible pedagogic materials.9 New curricula must compete for both funding and class time with other disciplines generated by the knowledge explosion (e.g., molecular biology and genetics); however, these are the very issues that demand a quantitative perspective.
Recent increases in the availability of books, case studies, online resources, and other pedagogic materials facilitate the delivery of quantitative curricula. Textbooks cover the core sciences of epidemiology,10 statistics,11 and outbreak investigation,12 as well as newer and increasingly relevant topics, such as economic methods13 and decision analysis.14 In addition to the availability of such material resources, programs in epidemiology may evolve because the presence in primary care (internal medicine and pediatrics) and preventive medicine departments of clinician—epidemiologists, who can both advocate and teach the courses on this subject matter. Some medical schools have approached the need to provide instruction in quantitative population-based methods by developing separate courses in medical decision making, and integrating such quantitative methods throughout the medical school curriculum.15,16
The integration of quantitative methods in medical education also requires that medical schools recruit or train faculty with such expertise and that curriculum committees develop methods for strengthening the implementation of the LCME standards. The examination bodies for both the basic medical science competencies and specialty boards (e.g., National Board of Medical Examiners, American Board of Internal Medicine) might complement the efforts of the medical schools by including questions that explicitly recognize epidemiology and other quantitative methods by measuring competency in quantitative reasoning and problem-solving skills as they relate to clinical abilities. In addition, because continuing education for physicians relies heavily on the programs and services of professional organizations (e.g., the American Medical Association, American College of Physicians, American Academy of Pediatrics, and American College of Preventive Medicine), these organizations also can play a major role in educating primary gatekeepers and other physicians about quantitative methods through increased emphasis in policy documents. Clearly, the high proportion of preventable problems confronting primary care practitioners and even specialists demands that medical school curricula transcend the traditionalist biomedical approach, aimed at diagnosing and curing the individual patient, and give major emphasis to the principles of quantitatively informed decision making based on approaches derived from the systematic study of populations within the community.
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