From the Guidelines
Anchoring bias most significantly impacted the course of care for this 73-year-old woman with end-stage kidney disease (ESKD). The healthcare providers likely fixated on her history of catheter-associated bloodstream infection and her presenting symptoms of nausea, vomiting, and weakness, which are common in patients with kidney disease. This initial diagnosis "anchored" their clinical reasoning, causing them to overlook or delay recognition of her cardiac condition. The patient's non-ST-segment elevation myocardial infarction (NSTEMI), mitral valve vegetation, and multiple emboli represent serious cardiac complications that may have been detected earlier if providers had maintained a broader differential diagnosis. Anchoring bias occurs when clinicians rely too heavily on the first piece of information received, failing to adequately adjust their thinking as new information becomes available, as noted in the American Heart Association's guidelines for the diagnosis and management of infective endocarditis 1. In patients with complex medical histories like ESKD, symptoms can be multifactorial, and cardiac manifestations may present atypically. To avoid anchoring bias, clinicians should systematically reconsider their initial impressions, particularly when patients with chronic conditions present with new or worsening symptoms, and maintain a low threshold for cardiac workup in high-risk populations. The use of the modified Duke criteria, as recommended by the American Heart Association 1, can help guide the diagnosis of infective endocarditis, but clinicians must remain vigilant for other potential causes of symptoms and avoid relying too heavily on a single diagnosis. By recognizing the potential for anchoring bias and taking steps to mitigate it, clinicians can provide more comprehensive and effective care for patients with complex medical conditions. The importance of considering multiple potential diagnoses and avoiding anchoring bias is also highlighted in the management of cardiovascular implantable electronic device infections, where a thorough evaluation and individualized approach are essential 1. In the context of this patient's care, the failure to consider a broader range of potential diagnoses and the anchoring on her initial presentation likely contributed to delays in recognizing and addressing her cardiac complications, ultimately impacting her outcome.
From the Research
Types of Bias
The patient's course of care was likely impacted by various types of bias, including:
- Anchoring bias: This occurs when a physician relies too heavily on the first piece of information they receive, even if it's incomplete or inaccurate 2.
- Availability bias: This happens when a physician overestimates the importance of information that is readily available, rather than seeking out a more comprehensive understanding of the situation 2.
- Diagnostic inaccuracies: Cognitive biases, such as overconfidence and lower tolerance to risk, can lead to diagnostic inaccuracies and medical errors resulting in mismanagement or inadequate utilization of resources 2.
Impact of Bias on Patient Outcomes
The impact of bias on patient outcomes is a significant concern, as it can lead to:
- Misdiagnosis: Cognitive biases can result in diagnostic inaccuracies, which can have serious consequences for patients 2.
- Inadequate treatment: Biases can also lead to inadequate or inappropriate treatment, which can worsen patient outcomes 2.
- Increased mortality: In some cases, biases can result in increased mortality, particularly in patients with complex or critical conditions 3.
Specific Biases in this Case
In the case of the 73-year-old woman, the following biases may have played a role:
- Anchoring bias: The patient's initial diagnosis of non-ST-segment elevation myocardial infarction (NSTEMI) may have anchored the physician's thinking, leading them to overlook other potential causes of her symptoms 2.
- Availability bias: The patient's history of catheter-associated bloodstream infection and end-stage kidney disease may have made the physician more likely to consider infectious causes of her symptoms, rather than other potential explanations 2.