How anchoring can cause medical errors focus of EMS Today session
EMS providers need to understand anchoring, a type of cognitive bias, to prevent errors in prehospital patient assessment and care
Editor's note: EMS1.com columnist Michael Gerber is presenting "The dangers of anchoring" at the EMS Today conference and exposition on February 28, 2015. Michael introduces 'anchoring' and previews his session in this preview article.
Dispatched for altered mental status, you find the patient’s wife waiting at the front door. She ushers you inside, saying, “I think my husband has had a stroke.” You confirm that the patient, a 68-year-old man, is slurring his words and seems weak. You’re pretty sure he has some facial droop as well.
You alert the hospital and start transporting, establishing an IV and placing the patient on the cardiac monitor. You arrive at the emergency department a few minutes later, where the neurologist and stroke nurse are waiting. You give your report, and then they ask you: Did you check his blood sugar?
Anchoring influences thinking and decision making
Anchoring is a type of cognitive bias — when context and our own experiences influence how we think and make decisions.
In this case, you anchored on the wife’s comment and immediately began assessing for signs of a stroke. Other biases came into play: The symptoms confirmed what you suspected because that’s what you were looking for (confirmation bias). You made a diagnosis and treatment plan before completing a full assessment (premature closure).
Research indicates that tens of thousands of people die each year in U.S. hospitals alone from medical errors. While the data is limited, experts speculate that the emergency department has a high rate of errors due to time-sensitive decision-making, overcrowding, and other factors. While much media attention has focused on errors such as incorrect medication dosages and wrong-site surgeries, errors in diagnosis probably cause more morbidity and mortality, and might be more difficult to prevent.
Error prevention in EMS
It seems clear that prehospital medical providers are just as susceptible to making cognitive errors, as many of the risk factors (incomplete information, fatigue, distractions, time constraints) are present with nearly every patient encounter. But it’s not hopeless — there are steps you can take to prevent cognitive errors from harming your patients. The first step is simply recognizing that cognitive biases exist and that you’re capable of making a mistake.
Not recognizing the risk factors for and signs of cognitive bias is as irresponsible as not learning ACLS algorithms or proper ventilation techniques — yet decision-making is hardly discussed in EMS classrooms today. Any EMS provider who wants to do what is best for their patients should take the time to learn more about preventing diagnostic errors in the field.