Being Biased Against Being Biased (Part One): Bias Boulevard

By George Barnes MS, CCC-SLP, BCS-S

Edited by Allie Mataras MA, CCC-SLP, CBIS

Everybody is a victim of cognitive bias from time to time. For most people, it’s a mild inconvenience occasionally forcing us into errors of judgment with unfortunate consequences. But bias exists in healthcare too and it affects patient outcomes. Anything impacting our judgment should be considered enemy #1 and should be combated in every way possible.

How Evolution Hurts our Practice

Through evolution, human beings have become proficient in making quick decisions using the quickest and often simplest answer. We see a snake, we run. We see a lion, we climb. We see an enemy, we fight. This type of thinking is referred to as system one, or fast thinking by renowned psychologist and economist, Daniel Kahneman. This way of thinking has worked quite well for an incredibly long time in human existence and is one of the main reasons we have stayed alive and thrived for so long. Unfortunately, in today’s age where we are expected to make decisions filled with complex factors textured with counterintuitive logic, thinking too fast doesn’t help us very much. In fact, it can hurt us and our patients in ways we never could have imagined.

Bias Boulevard

Thinking fast leads us down a slippery path, which I like to call Bias Boulevard. On Bias Boulevard the whole picture is blurry. The risks and benefits of any given direction are difficult to understand. And alternative routes to the most straight forward and simplest path are faded on our map. Let’s look at the all the biases we see as landmarks on our trip along Bias Boulevard. Each and every one is important to know and understand so we can avoid them from misleading us and our clinical decision making.

Order effect- The order in which we perform various aspects of an evaluation process changes the way we perceive that information.

Example: Doing a chart review before we see the patient (instead of after) allows us to pay attention to certain features we otherwise wouldn’t have known existed (i.e. a subtle yet meaningful left sided facial weakness from a right hemisphere CVA).

Availability heuristic- Putting too much weight on information that comes to mind easily.

Example: The SLP who has focused her entire career on dysphagia may put more clinical weight on the signs of symptoms of oropharyngeal dysphagia vs other, possibly more clinically important issues.

Anchoring- We anchor ourselves to a salient feature and use it to explain everything else.

Example: Using our knowledge of dysphagia to explain all other features of the patient (e.g. cough, pneumonia, dehydration, weight loss, etc.).

Confirmation bias forces this anchor deeper each and every day as we continue to focus solely on the dysphagia, assume all outcomes are a result of it, and ignore other possible causes (this can also be applied to certain types of treatment when we ignore alternatives).

Example: A patient coughing during meals is automatically assumed to have pneumonia because of the dysphagia. Meanwhile the opposite cause and effect (dysphagia as a result of weakness and lethargy AFTER a pneumonia) is never considered.

Base rate neglect- Ignoring what statistics say about a particular outcome in a specific population.

Example: Assuming the pneumonia is aspiration related without acknowledging that with only 5-15% of all community-acquired pneumonia being aspiration pneumonia, it is certainly possible for the pneumonia to have nothing to do with aspiration.

Risk aversion- The tendency to weigh more heavily the risks than the benefits of a particular decision.

Example: Weighing the risk of aspiration higher than the benefits of a patient’s preferred diet consistency on their nutrition and quality of life.

Framing effect- How a decision can be viewed differently depending on how it is presented.

Example: Telling a patient that he failed the swallow evaluation vs discussing at length the results of the exam and the implications of these results on their status and plan of care.

Zero-risk bias- Focusing on bringing the risk to zero vs mitigating the risk to a manageable state.

Example: Keeping a patient NPO instead of finding other ways to manage the risk of aspiration and pneumonia in a fruitless attempt to bring the risk of aspiration pneumonia to zero.

Hindsight bias- Changes to the way we see a decision before and after the outcome.

Example: We assume the patient’s pneumonia is aspiration-related before making them NPO. The patient develops pneumonia after they’ve been NPO and now we assume it’s not aspiration related. This, ultimately ignores the complex relationship of aspiration and pneumonia.

Sunk cost bias: Relying more on past decisions than on current and future options.

Example: We started a treatment plan of pharyngeal strengthening only to learn that the patient’s dysphagia appears related to esophageal dysfunction. Instead of using the new information to adjust the treatment plan, we feel compelled to finish the original plan of rehabilitation.

Commission bias: Weighing the risk of inaction heavier than action (The reverse is omission bias).

Example: Modifying a patient’s diet before an instrumental study can be conducted instead of continuing the current orders until we have the full picture.

Rational Road

The only way to drive straight on Bias Boulevard is to turn down another street: Rational Road (sorry, cheesy analogies with alliteration are kinda my thing). On Rational Road we have a road map that gives us a full, clear picture of the area, the alternative routes, and the pros and cons of each of those routes. Next week I’m going to get into how to counter system one thinking with the immensely creatively named, “system two” thinking. Trust me, it’s more interesting (and useful) than it sounds. See you there!

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Interested in reading more about biases in healthcare? See links below:
Evaluating the Presence of Cognitive Biases in Health Care Decision Making: A Survey of U.S. Formulary Decision Makers

Decision making biases in the allied health professions: A systematic scoping review

The thinking doctor: clinical decision making in contemporary medicine