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.
