By Dr. Anthony Policastro

In the past I have written about something called justification bias. That occurs when we dismiss bad news about someone we like or good news about someone we dislike.

There are other kinds of biases that we see. One of them is called anchoring bias. This occurs in medical practice.

A physician may see a patient with a group of symptoms. At that point a presumptive diagnosis is made. Then additional tests are obtained.

If the tests confirm the original diagnosis, that is great. However, if they do not agree with the original diagnosis, anchoring bias comes into play.

The physician may not give as much credence to the results. They do not agree with the original diagnosis. Therefore, it is better if they are not considered.

In 2023 a study was done on 108,019 ER patients. They presented to the ER with complaints of shortness of breath. In patients with known heart problems congestive heart failure can cause shortness of breath. However, so can a pulmonary embolus.

The patients were originally seen in triage and vital signs were taken. The preliminary complaint was then written on the patient’s chart. The patient then went back to see the ER physician.

What they found was that if the chart said shortness of breath the patients were more likely to have pulmonary embolism testing done. If the chart said congestive heart failure, the patients were less likely to have pulmonary embolism testing done. The anchoring bias was caused simply by someone writing Congestive Heart Failure on the chart.

I just completed this month’s pediatric review articles. They showed a similar pattern. There were two adolescents being treated for anxiety. Both of them were sent to mental health providers. Both of them ultimately had medical diagnoses that had anxiety as one of the symptoms.

One of them came in because her anxiety had been getting worse. She had high blood pressure. She had rapid pulse rate. She had a 17 pound weight loss over 5 months without being on a diet. The testing showed that she had thyroid issues causing the worsened anxiety.

The second one came in because he took an overdose. He had been having worsening anxiety as a symptom for the last two months. After they treated his overdose, they obtained his old records. He had gained 64 pounds in the last year compared to an average gain of 18 pounds in previous years. He had a small pituitary gland tumor that was causing both his weight gain and his anxiety.

Sometimes when we make a diagnosis, we become so anchored to that diagnosis, that it does not allow us to follow the path to what might be an entirely different diagnosis. It is due to anchoring bias.