By Leah Pierson
Medical students spend a lot of time learning about conditions they will likely never treat. This weak relationship between what students are taught and what they will treat has negative implications for patient care.
Recently, I looked into discrepancies between U.S. disease burden in 2016 and how often conditions are mentioned in the 2020 edition of First Aid for the USMLE Step 1, an 832 page book sometimes referred to as the medical student’s bible.
The content of First Aid provides insight into the material emphasized on Step 1 — the first licensing exam medical students take, and one that is famous for testing doctors on Googleable minutia. This test shapes medical curricula and students’ independent studying efforts — before Step 1 became pass-fail, students would typically study for it for 70 hours a week for seven weeks, in addition to all the time they spent studying before this dedicated period.
My review identified broad discrepancies between disease burden and the relative frequency with which conditions were mentioned in First Aid.
For example, pheochromocytoma, a rare tumor that occurs in about one out of every 150,000 people per year — is mentioned 16 times in First Aid. By contrast, low back pain — the fifth leading cause of disability-adjusted life years, or DALYs, in the U.S., and a condition that has affected one in four Americans in the last three months — is mentioned only nine times. (Disease burden is commonly measured in DALYs, which combine morbidity and mortality into one metric. The leading causes of DALYs in the U.S. include major contributors to mortality, like ischemic heart disease and lung cancer, as well as major causes of morbidity, like low back pain.)
Similarly, neck pain, which is the eleventh leading cause of DALYs, is mentioned just twice. Both neck and back pain are also often mentioned as symptoms of other conditions (e.g., multiple sclerosis and prostatitis), rather than as issues in and of themselves. Opioid use disorder, the seventh leading cause of DALYs in 2016 and a condition that killed more than 75,000 Americans last year, is mentioned only three times. Motor vehicle accidents are mentioned only four times, despite being the fifteenth leading cause of DALYs.
There are some good reasons why Step 1 content is not closely tied to disease burden. The purpose of the exam is to assess students’ understanding and application of basic science principles to clinical practice. This means that several public health problems that cause significant disease burden — like motor vehicle accidents or gun violence — are barely tested. But it is not clear Step 2, an exam meant to “emphasize health promotion and disease prevention,” does much better. Indeed, in First Aid for the USMLE Step 2, back pain again is mentioned fewer times than pheochromocytoma. Similarly, despite dietary risks posing the greatest health threat to Americans (including smoking), First Aid for the USMLE Step 2 says next to nothing about how to reduce these risks.
More broadly, there may also be good reasons why medical curricula should not perfectly align with disease burden. First, more time should be devoted to topics that are challenging to understand or that teach broader physiologic lessons. Just as researchers can gain insights about common diseases by studying rare ones, students can learn broader lessons by studying diseases that cause relatively little disease burden. Second, after students begin their clinical training, their educations will be more closely tied to disease burden. When completing a primary care rotation, students will meet plenty of patients with back and neck pain.
But the reasons some diseases are emphasized and taught about more than others often may be indefensible. Medical curricula seem to be greatly influenced by how well understood different conditions are, meaning curricula can wind up reflecting research funding disparities. For instance, although eating disorders cause substantial morbidity and mortality, research into them has been underfunded. As a result, no highly effective treatments targeting anorexia or bulimia nervosa have emerged, and remission rates are relatively low. Medical schools may not want to emphasize the limitations of medicine or devote resources to teaching about conditions that are multifactorial and resist neat packaging, meaning these disorders are often barely mentioned.
But, although eating disorders are not well understood, thousands of papers have been written about them, meaning devoting a few hours to teaching medical students about them would still barely scratch the surface. And even when a condition is understudied or not well understood, it is worth explaining why. For instance, if heart failure with reduced ejection fraction is discussed more than heart failure with preserved ejection fraction, students may wrongly conclude this has to do with the relative seriousness of these conditions, rather than with the inherent challenge of conducting clinical trials with the latter population (because their condition is less amenable to objective inclusion criteria).
Other reasons for curricular disparities may be even more insidious: for instance, the lack of attention to certain diseases may reflect the medical community’s perceived importance of these conditions, or whether they tend to affect more empowered or marginalized populations.
The weak link between medical training and disease burden matters: if medical students are not taught about certain conditions, they will be less equipped to treat these conditions. They may also be less inclined to specialize in treating them or to conduct research on them. Thus, although students will encounter patients with back pain or who face dietary risks, if they and the physicians supervising them have not been taught much about caring for these patients, these patients likely will not receive optimal treatment. And indeed, there is substantial evidence that physicians feel poorly prepared to counsel patients on nutrition, despite this being one of the most common topics patients inquire about. If the lack of curricular attention reflects research and health disparities, failing to emphasize certain conditions may also compound these disparities.
Addressing this problem requires understanding it. Researchers could start by assessing the link between disease burden and Step exam questions, curricular time, and other resources medical students rely on (like the UWorld Step exam question banks). Organizations that influence medical curricula — like the Association of American Medical Colleges and the Liaison Committee on Medical Education—should do the same. Medical schools should also incorporate outside resources to cover topics their curricula do not explore in depth, as several medical schools have done with nutrition education. But continuing to ignore the relationship between disease burden and curricular time does a disservice to medical students and to the patients they will one day care for.