Clinical Reasoning: When Beliefs Trump Evidence

I would really like to think that the clinical reasoning process is simply a matter of weighing evidence, applying the principles of logic and deductive reasoning, and making sound decisions based on the evidence. Sounds pretty simple, doesn’t it?

But I know better. It’s not just about evidence. It never has been. If it was, there would never be any emotionally-charged debates on an assessment method or a treatment technique.

Clinical reasoning involves beliefs – whether we want to believe so or not - and beliefs can have a significant disparity with scientific evidence.

We're all driven by our belief systems. We select data to support our beliefs. We impose our own biases on the world around us. Beliefs are not necessarily lies, but they aren’t necessarily the one-and-only “truth” either. Beliefs can trump evidence, sad as that may sound.

But if we know how we function, and we are aware of our thought processes, then we can have greater insight into all the factors that truly impact clinical reasoning. We can become better clinicians and, better yet, better people. With this in mind, I propose a new model for understanding the perceptual factors that influence the clinical reasoning process.

Let’s face it - the amount of data available to us for review is huge. This was astutely noted in the movie “What The Bleep Do We Know” (a movie that should be mandatory viewing for all clinicians). Our central nervous system has to filter out a great deal of the data available otherwise we would be in data overload.

Then we progress through a series of steps that are summarized nicely by Rick Ross’ “The Ladder Of Inference” in “The Fifth Discipline Fieldbook”. This (and the book that preceded it – Peter Senge’s “The Fifth Discipline”) was instrumental in changing the way that I view the world of perceptions and beliefs – and subsequently how these issues impact our clinical reasoning.

Our self image has a huge effect on how we perceive the world around us. This may in fact be one of the greatest limiters to our success as clinicians. It may also have a huge impact on our perceived role as either “guru” or “mentor”. Add to that the backwards incentives of the health care system (seeing a patient more frequently, or performing more procedures, equates to making more money), and you have a significant number of issues that affect clinical reasoning – most of which have nothing to do with “evidence”.

I have adapted Ross’ original diagram to include many other factors that affect how we perceive the world around us as clinicians, and the potential errors that are made in clinical reasoning. You can download the PDF version here. I would welcome any thoughts on this overview.

There are countless times in which clinicians have taken a hypothetical construct, loosely based it around some suspect correlations and data, and built a career out of it. Worse yet, many “approaches” are based on a belief system that is not founded in the truisms of physiology and is based more on statistical correlations rather than good clinical observation and cause-effect relationships. That is the unfortunate truth. That is when beliefs trump evidence.

Of course, if we all just stop for a moment and consider how we think and perceive the reality swirling around us, then the world might be a better place for more things than just clinical reasoning. But I digress.

Photo credits: Steve Rhodes