How anchoring leads to misdiagnosis

Anchoring refers to the tendency to latch on, or anchor, to the first symptom or bit of data and fail to consider the full spectrum of information, leading to misdiagnosis. Recently, we have received several cases where an anchoring error was triggered by a mistake in translating the patient’s words into clinical terms.

Case study #1

Henry Solomon, FACP, currently the medical director of Pfizer Global Pharmaceuticals, was for many years a cardiologist on staff at New York Hospital. He told us about the case of a 65-year-old man from Quito, Ecuador, who came to see him yearly for an “annual physical examination.” The patient, Dr. Solomon said, “was always asymptomatic, and had mild hypertension, mild dyslipidemia, was overweight, smoked cigars, had two drinks per day, and refused to change any of these behaviors or take any medications.”

Several months before his usual time to visit New York, the patient was lying prone on the beach, and felt his body slowly rising and falling. Thinking it might be a small earthquake or ground tremor, he looked around to see if others were similarly aware of such motion, but nobody appeared to be. The patient said he turned on to his back and the feeling stopped. Rolling again onto his belly, the feeling returned. The patient called his local physician who dismissed the symptom as “gas.”

The local physician, hearing what was clearly an unusual description of abdominal symptoms, was faced with the task of translating the patient’s complaint into clinical terms. Certainly, patients use all kinds of descriptors to refer to “gas,” such as rumbling, grumbling or squeezing. Furthermore, “gas” is used as an explanation for a variety of transient minor abdominal symptoms that are of no consequence and, in fact, may not be due to “gas.” Thus, it is not surprising that the local physician anchored on this diagnosis.

But, the patient felt the sensation was so unusual that he called Dr. Solomon in New York. Dr. Solomon elicited further history that the patient felt his body was literally rising and falling in a gentle rhythmic way while lying on his abdomen. The feeling went away as soon as he turned onto his back. He did the experiment three times and each time his symptoms were the same.

“As I mentally went through differential diagnoses,” Dr. Solomon said, “I couldn’t shake the idea that this could possibly be a large abdominal aortic aneurysm. When I explained my concern to the patient, repeating that this would be a rare and unusual presentation, I said that the seriousness of the possibility made immediate medical attention necessary. Against my every entreaty, he insisted he would fly to New York immediately. I explained the dangers of flying with that condition, that reduced cabin-air pressure could be disastrous, that immediate care was essential, but he ignored it all and said that he was coming to New York.”

Unable to dissuade the patient, Dr. Solomon said that he “arranged for immediate transport to the hospital from JFK International Airport and within two hours of arrival—fortunately he arrived intact—the patient was in the operating room where a huge, bulging, pulsating abdominal aortic aneurysm was successfully treated.”

Commentary

Dr. Solomon told us that he loves language. In this case, he took the time to really think about the patient’s words and to run through a differential diagnosis. He was able to translate the patient’s description and thereby arrive at what turned out to be the correct etiology, avoiding the anchoring error.

This patient presented with an unfamiliar description that was misleading to the local doctor. But sometimes even familiar descriptions can mislead a physician and lead to anchoring errors because the same words may have different meanings for the patient than for the doctor.

Case #2

Arthur Chernoff, ACP Member, chief of endocrinology at Einstein Medical Hospital in Jenkintown, Pa., shared with us the case of an 80-year-old man who required knee surgery for arthritis that severely limited his ability to walk. After surgery and rehabilitation, the patient was able to walk and ventured out on the golf course for the first time in several years. However, he reported that he was “fatigued” and had “no stamina.” The orthopedic surgeon referred him to his internist who sent him to a cardiologist.

An extensive evaluation showed normal pulmonary and cardiac function. The patient, having seen advertisements for testosterone therapy, said to his internist, “I hear testosterone can help your stamina,” and asked that he check his testosterone level. The internist complied and found a level of 242 ng/dL (where 240 was the lower limit of normal) and referred him for an endocrine evaluation.

Dr. Chernoff questioned the patient regarding libido and sexual function, and was told, “In this area, things are great.” Dr. Chernoff then said to the patient, “I want to hear in your words about the problem.” The patient replied as he had done before, “I have fatigue and lose stamina.” At this point, Dr. Chernoff said, “What do you mean by fatigue and lose stamina?” The man replied, “Whenever I walk, I lose stamina,” pointing to his calf. “When I stop walking, the stamina comes back and I can walk again.”

Dr. Chernoff told us, “It was a classic description of intermittent claudication.” On physical examination, a loud right femoral bruit was easily heard. Dr. Chernoff referred the patient to a vascular surgeon, and a successful angioplasty was performed. “The man is now back on the golf course,” Dr. Chernoff reported.

Commentary

It is easy to see how a physician could be misled by the words this patient used to describe his symptoms. It took an extra step to determine exactly what the patient meant by “fatigue” and “stamina.” Part of being an effective physician involves functioning as a translator of the patient’s symptoms, converting the patient’s words into human biology. Mutual understanding between doctor and patient is essential to ensure accurate diagnosis and appropriate medical care.

Dr. Chernoff concluded his description of the case as follows: “The reimbursement for the correct diagnosis: $. The reimbursements for all the unnecessary testing prior to the correct diagnosis: $$$$. The satisfaction in getting it right … priceless.”

Jerome Groopman, a hematologist-oncologist and endocrinologist, and Pamela Hartzband are staff physicians at Boston’s Beth Israel Deaconess Medical Center. They are authors of Your Medical Mind: How to Decide What Is Right for You. This article was originally published in ACP Internist.

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  • http://www.davisliumd.blogspot.com Davis Liu, MD

    Big fan of Dr. Groopman and the precision of language and being vigilant of cognitive errors, though do disagree with him at times. Will share with the medical students I train who often feel that the history is some quaint tradition that is somehow unnecessary and that real medicine is in the imaging and lab work, when it is in fact completely opposite!
    http://davisliumd.blogspot.com/2008/04/book-review-how-doctors-think.html

  • http://www.preparedpatient.org Dorothy Jeffress

    At the Center for Advancing Health, we have been working on this issue from the patient’s perspective…trying to offer simple basic strategies that support more effective and efficient patient/physician communications and use of health care. Here is a recent feature article from our Prepared Patient series: Talking About Symptoms with Your Health Care Team: http://www.preparedpatientforum.org/communicating/symptom.cfm

    Reproduction with attribution is free and welcomed.

  • jsmith

    Sorry guys, but this is not anchoring. Anchoring is when you firmly believe something and then refuse to change your mind when contracting information comes to light. I’m not sure the docs firmly believed anything here, at least from the descriptions. More likely they did not know what the heck was going on.

  • http://thehappyhospitalist.blogspot.com The Happy Hospitalist

    Most of my patients can’t even tell my why they are on coumadin. So I guess I’m screwed with the whole anchoring thing. I’ll cling on to anything.

  • http://www.myheartsisters.org Carolyn Thomas

    Hello Drs G & H – I tend to agree with jsmith here, particularly in the second case, which really lacked any kind of “latching on” to an initial symptom, but rather sounded like an ongoing process of correctly trying to eliminate what the problem wasn’t.

    When I showed up in the E.R. in mid-heart attack (chest pain, nausea, sweating, pain radiating down my left arm), you’d THINK that the guy with the letters M.D. after his name would have “anchored” on those textbook symptoms as being cardiac in nature. Instead, his “anchor” was that I was in “the right demographic” (his actual words) for having GERD, patted me on the head, and sent me home with instructions to follow up with my family doctor for antacid meds. Not even the pain down my left arm was able to budge him from his initial conclusion.

    I left hospital feeling supremely embarrassed and apologetic for having made a big fuss over nothing. Two weeks of increasingly debilitating symptoms went by (but hey! at least I knew it was NOT my heart!) and when these became truly unbearable, I returned to the E.R., this time to a revised Dx of “significant heart disease”, and taken immediately from the E.R. to O.R.

    My story is, sadly, not uncommon. Research reported in the NEJM showed that women heart patients under the age of 55 were seven times more likely to be misdiagnosed than men of the same age – with everything from anxiety to indigestion, gall bladder problems or just plain old menopause (an ideal all-purpose diagnosis!) The consequences of these misdiagnoses were enormous: being sent away from the hospital doubled the chances of dying.

    What both your examples do illustrate is that it was the patients – not the doctors – who persisted in the search for a correct diagnosis.

  • http://www.littlepatientbigdoctor.com Haleh Rabizadeh Resnick

    Dear Dr. Groopman,

    I have benefited much from the importance you place on truly understanding the patient’s perspective in health and the really listening to what patients say. My son was diagnosed with severe hearing loss at birth and it was not until I found a doctor willing to truly listen to my words rather than test results that we determined that the diagnosis was wrong and that hearing aids would have caused him permanent hearing loss.

    I’ve chronicled this experience and others in a newly released book, Little Patient Big Doctor: One Mother’s Journey, in which I also cite your book, How Doctor’s Think.

    Thank you for the work you do.
    Haleh

  • Robin

    Thank you so much for this article. Several years ago my grandmother, then 83 and living alone at an assisted-living facility, began complaining of stomach trouble. She told me on the phone that she hadn’t gone to the bathroom in three weeks. Her helper took her to the doctor, who prescribed laxatives, but that seemed to make things worse. She continued to have nausea and upset stomach and to tell me she wasn’t going to the bathroom.

    Finally, after much gentle coaching on my part, she managed to confess that she was actually having the opposite problem – severe diarrhea, which the laxatives had made much worse. What she had meant by “I haven’t gone to the bathroom in three weeks” was “I haven’t had a NORMAL bowel movement.” But she couldn’t bring herself to say the words “diarrhea” or “bowel movement.” I felt so bad for her, but the incident taught me a valuable lesson that came in handy later as she got older and needed more care.