How Doctors Think
By Jerome Groopman
“Different doctors have different styles of practice, different approaches to problems. But all of us are susceptible to the same mistakes in thinking.”
- From How Doctors Think by Dr. Jerome Groopman.
Dr. Jerome Groopman is an oncologist/hematologist and chief of experimental medicine at
Beth Israel Deaconess Medical
Center in Boston.
He has written several previous books and many magazine articles on
medicine and biology. These have
appeared in “The Boston Globe Sunday Magazine”, “The New Yorker” and “The New
Republic”, among others. My opinion is
that How Doctors Think, his latest
book, should be required reading for every medical student, intern, resident
and practicing physician. It wouldn't be a bad idea for patients who wish to better understand their medical care and insure that they are being treated for the proper diagnosis to read this as well.
The author notes the growing public demand for “quality of care” and reduction of medical error, citing recent reports from The Institute of Medicine and the National Patient Safety Foundation. He notes, however, that medical error differs from misdiagnosis. “It (misdiagnosis) is a window into the medical mind. It reveals why doctors fail to question their assumptions, why their thinking is sometimes closed or skewed, why they overlook the gaps in their knowledge. Experts studying misguided care have recently concluded that the majority of errors are due to flaws in physician thinking, not technical mistakes. As many as 15 percent of all diagnoses are inaccurate, according to a 1995 report which matches classical research, based on autopsies, which shows that 10 to 15 percent of all diagnoses are wrong.”
What are the flaws in thinking that lead to these misdiagnoses? Dr. Groopman, referencing experts in cognitive theory and psychology, discusses three main categories of flawed thinking. The first is termed “anchoring”. This is when the physician grabs on to the first symptoms discussed by the patient and comes to a snap judgment. The classic example of this is the overweight patient who complains of heartburn and is diagnosed with esophageal reflux when he actually is having angina. The second flaw derives from the first and is termed “attribution error” which is a sequence of diagnosis and treatment begun with anchoring and continuing because of the doctor’s stereotyping of the patient. Again, the physician has formed a quick first impression and doesn’t deviate from that assumption. The third and final flaw is called “availability error,” that is, when thinking is clouded by recent experience. In this example, the last thirty patients with this symptom have had reflux disease, so that must be what this patient has as well. He illustrates each of these cognitive errors with very compelling true life case histories, many from his area of expertise, oncology.
Dr. Groopman also has unkind things to say about how physicians are taught to diagnose and treat. He dislikes diagnosis decision trees and treatment algorithms, feeling they limit thinking and promote another form of error which is termed confirmation bias. In this setting the physician makes the data he obtains “fit” the algorithm which often leads to misdiagnosis and failed treatment. The author is also not a fan of evidence based medicine, feeling that it relies too much on numbers which may be generated by flawed or limited technology. He also feels that strict use of evidence based medicine leaves no room for intuition, “hunches” or thinking outside of the algorithm.
The author also warns against what he terms “diagnosis momentum”. This situation occurs when a patient is given a diagnosis by a specialist or academician and that diagnosis is never called into question by other physicians. The correctness of this diagnosis is never challenged, even if subsequent data may contradict it.
In the most important chapter in this book Dr. Groopman decries the lack of history taking skills in modern physicians. He quotes William Osler: “If you listen to the patient, he is telling you the diagnosis.” One study is cited where the average time from the first open ended question from the doctor to the time of the first interruption by the doctor was 18 seconds. “Technology has taken us away from the patient’s story” decries Dr. Groopman. Further: “Competency is not separable from communication skills. The art of medicine is the sensitivity to language and emotion that makes for a superior clinician.” Profound words, those.
Dr. Groopman suggests three questions which patients should ask their doctors when they feel they are not responding to treatment. These are:
1- “What else can it be?” This question should prompt the doctor to pause, think again, and extricate himself from a cognitive trap
2- “Could two things be going on to explain my problem?” This addresses the pitfall of “satisfaction of search”, so if the physician stopped looking after finding an initial abnormality (Ockham’s Razor), he or she will now consider multiple causes for persistent symptoms.
3- “Is there anything in my history, physical examination or lab tests that seems to be at odds with the working diagnosis?” This question is an important safeguard against confirmation bias (making the data fit the diagnosis).
All of these seem to be reasonable questions a patient can use to refocus their diagnostic and treatment process when things are not going well.
I have only two complaints about this book. The first is that the author only spends one paragraph describing “defensive medicine” and the impact of litigation on decision making. There is no denying the reality that the shadow of malpractice litigation falls on every medical decision made and I think the author underplays it. The second complaint that I have is that he glosses over the business side of medicine. He does spend some time describing economic pressures which have dramatically increased the number of patients physicians must see daily just to remain economically viable. This obviously decreases the amount of time spent with each patient and increases the likelihood of cognitive as well as other errors. He never really delves into the cost of following “hunches” or thinking outside of the algorithm. The cost of searching for obscure or unlikely diagnoses is never really brought into the argument.
This book has already changed the way I practice. I find myself reviewing lab and radiology data looking for inconsistencies with my diagnoses. I am wary of “diagnosis momentum” and find myself asking a long-time patient the question “Let’s start over and tell me how all of this started again?” I try not to stereotype patients and try to look past “non-compliance” as a diagnosis and try to find out why a patient is non-compliant with their treatment regimen. I try to let a patient talk for more than 18 seconds. Read this book, you’ll be glad you did.