Why Attribution Bias Might be the Costliest Bias

And why primary care is so important for reducing it

I am a total sucker for an article that argues for the importance of primary care. I am also obsessed with our diagnostic reasoning biases. Pat Croskerry’s 2002 article in which he identifies 30 “failed heuristics, biases, and cognitive dispositions” is one of my absolute favorites that I reference a few times a year. In this article, Dr. Rohlfsen discusses the importance of attribution bias, one not even discussed by Croskerry.

Adam Cifu

To paraphrase Shaw and Hawking, “The greatest threat to diagnostic excellence is not lack of a diagnosis but rather the illusion of a diagnosis.”

Bias distorts our perception and leads to errors in diagnostic reasoning. Some errors are inconsequential. Others can be the difference between life and death. It is this fact that has caused diagnostic excellence to gain such traction as a priority in medical education the past 5-10 years. Here I describe why one type of bias - Attribution Bias - is the costliest of all. It also happens to be the reason I decided to become a primary care doctor.

Attribution bias in medicine occurs when symptoms are attributed to an unrelated diagnosis or test result.

When I was a trainee rotating on sub-specialty services, I repeatedly witnessed the harms of misdiagnosis. Inappropriate procedures, costly admissions, and unnecessary downstream testing stemmed from incidental findings and unimportant lab abnormalities, many of which originated from a primary care office. Consultants (it turns out) are really good at answering questions. Unfortunately, not all questions are good ones, or even need to be answered, and many cannot be answered without a cascade of interventions.

But, for the unsuspecting primary care physician, “ask and you shall receive.”

I’ll never forget one Rheumatology clinic in which a patient was referred for fatigue, intermittent shortness of breath, and the dreaded “positive ANA.” As is often the case, this patient had no symptoms or signs that would support a diagnosis of lupus. She had been waiting six months for this appointment and was deeply invested in rheumatologic possibilities from a home internet search. It wasn’t too long into the visit that I realized she had an irregular pulse and diagnosed her with atrial fibrillation. I was ecstatic to tell her the good news, “You do not have a rheumatologic condition!”

“… but you could have a stroke or heart failure if you don’t get to the right place, so let’s get an EKG to confirm.”

My attending at the time reached out to a cardiologist and she was started on a beta blocker and anticoagulation shortly thereafter. I didn’t tell her she was lucky to have made it half a year without any complications.

Misdiagnosis in this case was due to attribution bias – attributing her symptoms, fatigue and dyspnea, to a non-specific lab abnormality. Other possibilities were dismissed or ignored. Otherwise known as a red herring, this type of bias is never benign.

Attribution bias may or may not lead to lapses in care but it usually adds a layer of harm – a false pursuit. It’s marked by not one but two types of error:

·       Type 1 error: false positive – the innocent is convicted (e.g. lupus)

·       Type 2 error: false negative – the guilty goes free (e.g. A fib)

The first error leads to downstream tests, inappropriate utilization of care, and risks unnecessary harm if a false diagnosis is accepted as true (error of commission). The second error blinds the diagnostician to the true culprit such that treatment is delayed (error of omission).

This is why I am passionate about diagnostic excellence in primary care – it’s where we make the biggest difference as clinicians. The provision of safe, effective, patient-centered, timely, efficient, and equitable care hinges on a correct diagnosis. Nothing compromises these 6 pillars of quality faster than the outsourcing of the diagnostic process to a specialist.

No one approach is best for patient-centered care because each clinical context is unique. A minimalistic sequential approach to testing and referrals may be required in one scenario (“tincture of time”) whereas a shotgun of referrals (“cry for help”) may be equally appropriate in another scenario. This varied and integrated practice is our specialty as generalists. Navigating uncertainty with an appropriately calibrated set point is the mark of a skilled primary care physician. Being able to direct a care plan in the right place at the right time requires diagnostic expertise. These skills are something we should all espouse more as we seek to raise the bar in primary care.

Cory J Rohlfsen is a hybrid internist, core faculty member at UNMC, and the inaugural director of Health Educators and Academic Leaders which focuses on competency-based approaches to developing future leaders, scholars, and change agents in health professions education.