“Anchor Bias” May Have Played a Role in This Delay in Diagnosi
Published on MagMutual (https://www.magmutual.com)
“Anchor Bias” May Have Played a Role in This Delay in Diagnosis
Claim
The Case:
This case involves an alleged 12 hour delay in diagnosing transverse myelitis in a child, leading to an
extended hospitalization with residual arm and hand weakness and functional limitations. The young
boy complained of sudden onset, severe headache; numbness and tingling in his hands; and the
inability to participate in his afternoon activities. He was transported to a local children’s hospital
emergency department (ED) via ambulance. The ED physician tested and observed the child for over 5
hours. Her findings were inconsistent. The child continued to report that he could not move, but the ED
physician observed him smiling and laughing. After a social worker’s evaluation, the ED physician
“anchored” herself to a diagnosis of conversion disorder (neurological symptoms without a neurological
cause) and discharged the child. The following morning, the child could not move from the shoulders
down and had lost urinary bladder control. He was transported back to the ED via ambulance. A second
ED physician ordered a lumbar puncture, labs, MRI of the brain and spine and a pediatric neurology
consult.
The differential diagnosis focused on stroke of the spinal artery or transverse myelitis. The child was
hospitalized for over three months. At discharge from the rehabilitation unit, he could walk, had a
normal gait, but suffered from upper extremity limitations.
Risk Management Commentary:
Defending the standard of care was difficult for the first ED physician.
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“Anchor Bias” May Have Played a Role in This Delay in Diagnosi
Published on MagMutual (https://www.magmutual.com)
Expert reviewers opined that her diagnosis of conversion reaction is a “diagnosis of
exclusion” and that she had not done enough to exclude other neurologic causes for the
patient’s symptoms.
One of the experts discussed the role “anchoring bias” may have played in the ED physician’s
faulty decision-making.
“’Anchoring’ or ’focalism’ is a cognitive bias that describes the common human tendency to rely
too heavily on the first piece of information offered (the anchor) when making decisions.”1 One starts
with an implicitly suggested reference point (the "anchor") and makes incremental adjustments based
on additional information to reach their final decision. The adjustments may be insufficient, giving the
initial anchor a great deal of influence over the outcome.
A neurology reviewer presented a causation defense that an earlier diagnosis and treatment
with high dose steroids, would not have changed the patient’s outcome in this particular case, as
the child was outside the effective steroids treatment window.
While a neurological consult may not have been required, all of the reviewers agreed
the standard of care required the ED physician observe the patient’s gait and station, and obtain
a MRI before discharging him.
1Anchoring http://en.wikipedia.org/wiki/Anchoring [1]
More reading: Emergency Medicine Blog-Heuristics and Cognitive Biases in Decision Making during
Clinical Emergencies,
The case report presented is a composite drawn from MagMutual’s case files. Any similarity to a specific
case is both coincidental and unintended.
The information and resources provided in this course or publication have been prepared to provide
general information only. It is not to be relied upon in lieu of or as a substitute for legal, medical or other
professional advice. The laws, rules, regulations and case law may differ in your state. Please consult a
licensed attorney in your state for specific questions and advice. While all care has been taken in the
preparation of this course or publication, no responsibility is accepted by MagMutual Insurance
Company or the MagMutual Patient Safety Institute or its employees or agents for any errors, omissions,
or inaccuracies, or for any known or unknown consequences that may result from reliance on any
information provided in this publication.
Source URL: https://www.magmutual.com/learning/claimslesson/%E2%80%9Canchorbias%E2%80%9D-may-have-played-role-delay-diagnosis-claim
Links
[1] http://en.wikipedia.org/wiki/Anchoring
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