Anchoring Bias: When Assumptions Replace Assessment
Unfortunately, it’s likely that most clinicians have seen some form of anchoring bias in their experience.
Anchoring bias occurs when a clinician fixates on an initial piece of information, the “anchor”, and fails to adequately adjust their clinical approach as new data emerges. In long-term care (LTC), where staff know residents well and see them daily, anchoring can develop subtly. Familiarity can create confidence, and sometimes overconfidence, in early impressions.
Legal Implications of Anchoring
Regardless of where anchoring shows up or which member of the clinical team is exhibiting this bias, be it the doctor, advanced practice provider, nurse, or nursing assistant, there are substantial legal implications to consider when it is identified. Some of these including failure to diagnose, delayed treatment, missed patient deterioration, inadequate reassessment, and failure to escalate care – all of which can, and unfortunately do, negative affect clinical outcomes.
What I would look for to identify anchoring: an early diagnostic label that persists, lack of documented reassessment following the initial diagnosis, lack response to treatment, ignored abnormal trends (vitals, labs, mental status), escalation delays, and documentation that copies prior impressions without analysis, despite new data. Once anchoring is identified, the timeline is critical. Lining up initial impression, new findings, and clinical response, builds a telling story where bias patterns become obvious.
Clinical Scenario
Although this scenario is fictional, urinary tract infections are common in long term care facilities and have a wide range of presenting symptoms, making this an effective and realistic example of what anchoring bias could present as in an LTC environment.
In this case the resident is an 82-year-old female with a history of moderate dementia, recurrent UTIs, type 2 diabetes, chronic kidney disease stage 3, and hypertension. At baseline she ambulates with walker, is conversational and pleasant but forgetful, eats independently, and has stable vitals grossly within normal limits.
Day 1 – Nursing assistant reports: “She’s more confused today.” The primary nurse notes: increased agitation, refusing breakfast, strong urine odor, temp: 99.4°F (mildly elevated), BP: 118/72 (normal), and HR: 88 (normal)
A nursing assessment was documented saying: “Likely UTI – similar presentation in past.” Urinalysis was ordered and collected. No further workup initiated.
Day 2 - Today, the resident is noted to be somewhat lethargic (abnormal), now incontinent (new), poor oral intake, BP: 102/60 (normal, but on the lower side), HR: 104 (mildly elevated), temp: 100.2°F (elevated).
Urinalysis returns: positive leukocytes, bacteria present, no urine culture obtained. Provider orders oral antibiotics. No bloodwork ordered. No sepsis screening documented.
Day 3 – At this time, the resident minimally responsive, BP: 86/50 (low), HR: 118 (high), O2 sat: 90% on room air (low). She was transferred to hospital following the acute decompensation.
Hospital findings included: septic shock, pneumonia with large infiltrate, acute kidney injury, and positive blood cultures.
Obviously, the LTC facility missed something here.
Where Anchoring Bias Occurred
The “anchor” diagnosis was history of recurrent UTIs. Once confusion and “strong” urine odor were noted, staff locked onto UTI as the cause. And therefore, the subsequent findings were filtered through that assumption. The high heart rate (tachycardia) was attributed to the presumed infection. The low blood pressure (hypotension) was attributed to presumed dehydration. And likewise, the lethargy was attributed to presumed UTI worsening. Furthermore, the urinalysis result reinforced the anchor diagnosis of UTI, even though having a collection of bacteria in a resident’s urine is seen in up to 50% of LTC residents[1].
So, what was missed here? To start, the documentation should have included a full respiratory assessment, lung sounds documentation, oxygen saturation trending, broader infection differential including lab work and urine culture (even in the setting of a presumed UTI), and sepsis protocol activation based on the vital sign abnormalities.
How I Can Help Your Case
I can help identify clinical reasoning breakdown, identify deviation from the standard of care and regulation, and determine whether anchoring bias contributed to harm.
Cognitive bias is a quiet force in healthcare. It is often invisible in the record, yet evident in the trajectory of care.
By evaluating cases through a structured, systems-based approach, I can help identify where anchoring may have influenced clinical reasoning and where reassessment or escalation failed to occur. Let’s work through this nuance together.
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