Cognitive Errors are errors in thought processes or ways of thinking. In human medicine anywhere from 15-30% of internal medicine cases are misdiagnosed. Due to our limitations in veterinary medicine, we can assume our misdiagnosis rate is higher. 80% of misdiagnoses are due to cognitive errors, and about half of misdiagnoses lead to harm to the patient.

This means that at least 12% of our medicine patients suffer harm from errors in our thinking processes. That’s more than 1/10!

By addressing these medical biases, and actively working to limit their affect on our practice, we can improve patient care!

In this 3 part blog we will look at the the 10 most common medical biases, and how to combat these biases!

Continuing on a current treatment plant despite no clinical improvement OR ignoring/inappropriately assessing new information.

This more commonly occurs when a ‘senior clinician’ (specialist, senior vet, another clinic you perceive as more advanced) has made the initial diagnosis.

COMBAT THIS BIAS:
- Re-assess each case with each new shift or each day.
- Never ignore information. If a diagnostic doesn’t fit with your diagnosis, either prove to yourself that test was flawed (don’t just assume) or find a reason… which might mean a different diagnosis.
- Assess the case from the beginning assuming your initial diagnosis is wrong.

Basing clinical decisions on your expectation of clinical signs, instead of what you are finding.

Ex. Breed bias: 12yr GSD with hemoabdomen: assume a bleeding tumor instead of rat-bait.

COMBAT THIS BIAS:
- Ensure you are ruling out other ddx
- Gather enough data to CONFIRM your diagnosis
- Make a Problem List and DDX list for ALL cases!

Favouring an easily concluded diagnosis. This can be due to either recently missing this diagnosis in a previous case, seeing this diagnosis recently, or having an incorrectly increased perception of prevalence of a disease. Basically, favouring the diagnosis that most easily/first comes to mind, instead of thinking hard about other possible diagnoses.

COMBAT THIS BIAS:
- Being aware that this bias exists
- SLOW DOWN!

This is an individuals tendency to either ACT (Commission) or NOT ACT (Omission). Some doctors are the ‘wait and see’ type, and others are the ‘test for everything right now’ type. The doctors that are ‘wait and see types’ will miss things more often, and those that ‘test for everything now’ are more likely to over test, or over-treat.

A common manifestation of this is seen in the GP vs. Emergency approach, where GPs tend to have more of an Omission Bias and Emergency tends to have more of a Commission Bias.

Ex: The vomiting dog. Commission Bias will want to do x-rays and possible exploratory surgery, where Omission Bias will try maropitant and monitor response to therapy.

COMBAT THIS BIAS:
- Being aware of your own tendency
- Actively counteract your natural bias

Interpreting and considering information to fit a preconceived or desired diagnosis.

Ex. Dysuria in a dog- Finding hematuria and interpreting this as evidence of a UTI instead of using this as a piece of the puzzle and not pursuing culture/imaging to rule out a tumor- because you love this patient and don’t want it to have cancer, or because a UTI is easier to manage.

COMBAT THIS BIAS:
- SLOW DOWN
- Create Problem Lists and DDx lists for all cases
- Interpret and consider ALL information
- Do not over-interpret a single test

Medical Biases are present in all of us, whether or not we want to admit it! By addressing and actively working against these biases we can drastically improve how we perform medicine.

In Part 2 we will discuss the following biases...
6. OUTCOME BIAS
7. PREMATURE CLOSURE/SEARCH SATISFACTION BIAS
8. SUNKEN COSTS BIAS
9. TRIAGE BIAS
10. BELIEF BIAS

In Part 3 we will discuss how to combat biases… If you feel that you may be suffering from Medical Biases, or if you feel that your team or clinic may be suffering, and a presentation with a Q&A or webinar on these biases and how we can combat them please feel free to Contact Us at anytime.