By Mackenzie Poole

“It’s all in your head.”

When my friends, family, and mentors said these five words to me in the days leading up to the pre-pass/fail USMLE Step 1 exam, they meant it literally: everything you need to know to succeed is already in your head. When my internal dialogue repeated those words, they took on a different meaning. The question banks had been answered, and the Anki cards had been strategically reviewed. The practice tests revealed that I was in a strong position for success. Strong enough to the point, in fact, that I refused to believe it. Yet with every new piece of information, I tried to cram into my head, every enzyme on the protein synthesis pathway that I swore would give me the competitive advantage, I pushed myself further into doubting all of that previous work. The new facts began to muddy the clarity of the concepts I had already mastered. It was almost as if with each new fact I discovered and reviewed, I dreaded studying more and more for fear that I would uncover more gaps in my knowledge.

’m not here to share the narrative of a poor Step 1 experience or lament what could have been. The truth, however, is that upon leaving that lifeless examination room, I knew that the time I had spent dutifully preparing for that day over the past many years had been diminished by a “dedicated study period” that I had instead dedicated to over-preparing and perseverating on perceived weaknesses. So much stake was placed on a single day, only to underperform. My score was enough, sure, even more than enough to be considered competitive, but I think I speak for most of my fellow colleagues in the profession of medicine in saying that enough will never be enough for us; only our absolute best will ever be sufficient.

Soon enough, it was time to begin structured studying again, this time for the NBME subject exam that ominously waits after each third-year clerkship. In the weeks since I took Step 1 and received my score, I reflected on the unhappiness, anxiety, and imposter syndrome that clouded my acquisition of new facts leading up to test day. I then decided to take the road less traveled and ditch the study tools that had become a task rather than a benefit and those whose interfaces didn’t promote my personal learning style. I studied for my patients, read medical news articles that pertained to my rotations, and paid focused attention in didactics and on rounds. When I told my friends how I was preparing, they seemed concerned and touted their own strategies. But I knew my scores on the practice exams, and I knew that the time I had spent participating in the clinical side would pay dividends for my own learning style, dividends I would not have acquired had I decided to answer flashcards on rounds instead of focusing upon the plan for each patient.

I am not sure if the strategies of my colleagues’ worked, but I know that mine did. I stuck with my blue ocean strategy for the remaining six clerkships and was never disappointed. When the time came to schedule USMLE Step 2 CK, I knew how well I had scored on the seven subject exams. “Is ten days enough?” I asked my advisor. She was proud that I had learned from the preparation mistakes of the past and encouraged me to proceed onward.

For those ten days, I took one practice test and read over notes from the questions I had missed on clerkship practice exams over the past academic year. I completed practice questions only on the social science materials that had faded into the depths of my temporal lobes since prepping them a year prior for Step 1. There was no time to waste reviewing what I already knew for the sake of confidence. When I walked into the same lifeless examination room, I knew in my heart this time that it was all in my head. When I received my score, my instincts were confirmed.

It was not until several months later when I was reading for a master of business administration (MBA) economics course, that I realized the principle underlying my differential success in preparing for Step 1 versus Step 2. In the production process of every product or service, there comes a point at which adding an additional unit of input to the system actually leads to a smaller output, or return, per unit of input. Commonly known as the law of diminishing returns, this economic principle teaches that to maximize productivity and keep costs low, firms should produce up to this point but not past it, as the costs associated with producing that unit exceed the revenue that could be generated from selling it. In fact, firms that maximize profitability are those that set their marginal revenue, or the incremental gain from producing one additional unit, equal to their marginal cost or the incremental loss associated with that production. When I began unnecessarily cramming facts that I already knew for Step 1, my marginal cost exceeded my marginal revenue, and the profitability of my efforts began to fall. One day before Step 2, for example, I realized that if there was a question on renal tubular acidosis, I would get it wrong. Despite this, I was aware that the effort I put into studying it or the mental energy I invested would likely yield a smaller return in terms of increased scores or a less substantial outcome than reviewing epidemiological equations again. Interestingly, there were no questions on renal tubular acidosis on my exam.

Lessons from lean management theory also provide a metaphorical framework to reduce waste and limit variability when dealing with the precious asset of mental capacity. Even the pioneering Toyota Production System now recognizes non-utilized talent as an eighth source of waste that limits systems from operating most efficiently. The concept of eliminating non-value-added activities, or muda, is touted in programs as ubiquitous as Six Sigma in supply chain management. Simply put, this idea underscores that the most efficient operational models are those that eliminate any activities that do not increase the value of the final product. When capacity is constrained, eliminating contributions from the eight wastes can improve output and therefore improve revenue generation. Compared to Step 1, my preparation for Step 2 eliminated a source of waste in the form of overprocessing. For me, studying protein synthesis and renal tubular acidosis were non-value-added activities. Studying the work-up of biliary colic one more time “just because” was not going to get me an extra point on Step 2 because I had already learned the process well enough by working-up patients with that chief complaint in real-time during at least four clinical rotations.

I am not so naive as to assume that the mental cost of preparing for grueling standardized exams can be simplified into a mathematical equation or curve. However, I believe that the hours of showing up leading up to these exams, if used appropriately, build the economies of scale needed to keep marginal costs low most of the time. There is a point in our profession as professional learners, however, where we must foster an awareness of the point on the curve in which the slope of our marginal returns curve starts to flatten, where the mental cost of doing that extra question set or staying late “just because” is more than any knowledge gained by going through those motions simply because our colleague said he or she did. Learning to stay on the upsloping side of this curve might be the first step in preventing a career in which we fall victim to the disengagement and impacted care that results from the crisis of physician burnout. Maybe more isn’t really; in fact, always more, despite that mantra being quite literally burned into our workflows from the beginning of training onward.

Another factor to consider is that the point at which marginal costs equal marginal revenue, or the point of profit maximization, looks different for each and every product and service on the market. So too, does this tradeoff occur at a different work-life balance for each medical professional. And just as different costs are associated with the production of different goods, the weighted costs associated with fatigue, time spent away from loved ones, and increasing administrative roles outweigh the weighted esteem associated with a higher test score, more publications, or a prestigious residency or faculty position. The key is not finding a certain point on the curve. The key is finding the set of variables that define our unique point of diminishing returns on the curve and maximizing our potential there.

The takeaway here is not that less is always more or that the costs of a little motivational stress every now and again do not help push us to slightly higher marginal revenue in the complicated career path we have chosen to undertake as medical providers. The stakes are likely much larger than a score on a standardized test. I would argue that recognizing where our personal boundaries conflict with our care is pivotal in providing optimal patient care as well. The earlier we identify our tipping point, the sooner we find a career path that balances our call to medicine with our humanistic desires to engage in activities outside our scope of work.

The night before Step 1, I read the translation of Lao Tzu’s poem that advises readers to “retire when the work is done” because “that is the way of heaven.” And so I challenge my colleagues to find the point on the curve when our work is done. May we meditate on a promise to ourselves, to our loved ones, and to our patients that we will manifest a balance.

Mackenzie Poole is a medical student.