Identifying Risk Factors for Anchoring Bias during Emergency Department Transitions of Care

Author: Roni Matin, MSc (2022)

Primary advisor: Susan Fenton, PhD

Committee members: Amy Franklin, PhD, Robert Murphy, MD, Amit Mehta, MD

PhD thesis, The UTHealth Houston School of Biomedical Informatics

ABSTRACT

Transitions of care have been associated with breakdowns in communication and medical errors. In emergency departments (ED) these handoffs are typically known as sign outs. Sign outs provide continuity of care for ED patients whose diagnosis and care fall across shift changes. They are short interactions where pertinent information and responsibility for the patient is transferred to the physician assuming care for them. However, these exchanges may also be an opportunity for cognitive biases to be transferred or introduced, leading to erroneous decision making. Anchoring bias is known to have a significant impact on clinical decision making. Yet, little is known of the factors that increase the risk of anchoring bias during patient diagnoses that involve sign outs.

This exploratory research aims to understand how the communication of patient information during sign out influences the clinician’s use the information and develop the patient’s diagnosis and thus identify the factors that contribute to anchoring bias in clinical decision making in the ED.

A mixed method approach was used to identify and evaluate potential risk factors for anchoring. Initially a review of a dataset from a medical incident reporting system was conducted to identify potential contributing factors from known cases of medical error. This was followed by an interview study with emergency medicine (EM) physicians to gain their perspectives on peer influence and communication factors between outgoing and oncoming clinicians that might affect sign outs and thus potentially impact decision making.

The findings were used to design an experimental evaluation study to assess the impact of potential risk factors identified on diagnostic and treatment planning of EM clinicians. The study was conducted using patient case vignettes as control cases and stimuli cases, which contained these risk factors as test conditions to assess their effect on clinical decision making. The cases were presented in a format simulating sign out communications and the volume of information presented at sign out. Volume of information was represented by the two test conditions of explicitness of the sign out information and the stage in the diagnostic process the case was in at the time of sign out. The study was conducted at two academic hospital ED sites with a total 69 participants.

The results indicated that the explicitness of the sign out information had no significant influence on the diagnostic accuracy in stimuli cases or on the confidence of the clinician participants in their diagnosis for the case. However, the stage in the diagnostic process of the case at the point of sign out, did significantly influence both clinicians’ diagnostic accuracy and their confidence in the diagnosis. The earlier stage stimuli cases were associated with lower diagnostic accuracy and lower confidence in the diagnosis. The test condition of explicitness did not have a significant effect on a number of outcome measures whereas the test condition of stage of the case did not.

These findings suggest that additional support may be required for during sign out for cases that are in an earlier stage in the diagnostic process at the time of sign out to as they are at higher risk for diagnostic error and for the influence of anchoring bias.