Staying Sharp with Occam’s Razor

The operational platform of EMS is comprised of four essential pieces. Once we meet our patient, we must identify problems, set priorities, develop a care plan and then execute the plan—arguably all much easier to write than to actually perform. Nonetheless, we are called upon to deliver prehospital care hundreds of thousands of times each day across the U.S. and virtually every call follows that four-part process.

Solid critical thinking and clinical decision-making drive every successful patient event. This month in BTB, we are looking at a very unique critical thinking tool and how, when properly used, it is beneficial for both you and your patients, as it helps you think critically and your patients get better care. That tool is Occam’s razor.

William of Ockham (or Occam) (1287–1347) was a Franciscan Friar, scholastic philosopher and theologian, born in the small village of Ockham in Surrey, England. It was common in that day to use your first name and place of residence rather than one’s given surname. In his time, he was considered to be at the forefront of medieval thought, though he’s most commonly known today for “Occam’s razor,” a model/methodology for analysis and decision-making. For our purposes, the term razor is used to describe the “shaving away” of unnecessary assumptions or details when working through two or more hypothesis, or by cutting apart two or more similar conclusions.

The backbone of Occam’s razor is straightforward, and when I was first exposed to it, it was explained to me as: “When confronted with any problem, challenge or quandary, the most simple and logical explanation is almost always the right one.” Clearly, finding the “right” solution to every patient’s needs is the goal we must strive to achieve on every single call we run.

Over the years, there has been much “restating” of the razor, and I’d like to share some of those that apply to our craft.

“The simplest explanation for some phenomenon is more likely to be accurate than more complicated explanations.”

For example, you are standing outside and suddenly you begin to get wet. Why? Simple logic would dictate it is raining. Of course, it could be that the timer has turned a sprinkler system on. Or a neighbor is being inattentive while washing their car and their overshoot is washing you instead. Four small children have conspired and decided to wet you down with their water blasters rather than wet each other. Then again, maybe a flock of seagulls has flown overhead. While all remain possible, as one gets further away from the simplest most logical choice (rain), the probability of each occurrence gets smaller. That is clearly a blessing in the case of the seagulls.

Another restating of Occam’s razor: “The explanation requiring the fewest assumptions is most likely to be correct.”

Every day, on every call, you are required to make many assumptions. And with each assumption there comes an increase in the likelihood of error. The patient’s chief complaint is either true or they are withholding information or fabricating information for other purposes, e.g. drug seeking behavior. The patient is either compliant with their medication regimen or they are not. Their past medical history is either true or it’s not. The history of the event today is either factual or false. As you see, each call involves multiple assumptions, and depending on which ones get made, the challenge of patient care gets simpler or more complicated.

Luckily for all who practice medicine, the vast majority of medicine follows predictable, logical pathways. Most patients don’t lie to us. Certain signs and symptoms are associated with specific diseases or conditions.

Part of being successful with Occam’s razor requires that you as a provider have an adequate fund of knowledge. In addition, you must cultivate the art of pattern recognition as you identify and treat certain pathologies repeatedly during your career.

I believe one of the defining characteristics of a great clinician is they do no more than is required to get the job done, yet do just exactly enough to make certain the job is done properly.

Part of that type performance is rooted in yet another restating of Occam’s razor, and that is the old medical adage, “When you hear hoof beats behind you, think horses, not zebras.” Nine days out of 10, you are right on the money with horses. To capture the remaining 10% of the outliers that don’t follow the textbook pattern, consider that those hoof beats you are hearing could, in fact, be zebras. So while you work with logic and pursue simplicity in solutions, a part of your clinical brain keeps alive the possibility of the small percentage of occasionally or rarely seen conditions.

When working through a complicated differential diagnosis, at some point you must whittle down your list of “possible problems” to a working diagnosis. Occam’s razor will help you look at the simple first, before moving on to the complex.

Until next month…

Mike Smith, BS, MICP, is director of clinical education and lead instructor for the Emergency Medical & Health Services program at Tacoma Community College in Tacoma, WA, and a member of the EMS World editorial advisory board.