The trouble with Dr. Jerome Groopman‘s book, How Doctors Think, is that the docs who really need it won’t read it.  But patients will, thanks to word-of-mouth buzz since it was published in 2007.

As a patient who has experienced a life-threatening misdiagnosis while having a heart attack, my own favourite part of the book is Dr. Groopman’s review of physicians who take “cognitive shortcuts’ during patient visits.

This means that doctors can jump to conclusions about diagnosis or treatment options, and then can’t budge even when contradictory evidence subsequently emerges. “Blame the 18 Second Rule!” advises Dr. Groopman, professor of medicine at Harvard. ”That’s the average time it takes a doctor to interrupt you as you’re describing your symptoms. By that point, he/she has in mind what the answer is, and that answer is probably right about 80% of the time.”

You may be saying by now: “Well, Carolyn, being right 80% of the time sounds like a pretty darned good track record, even if the doctor has jumped to conclusions and interrupted me after just 18 seconds!”  This may be true, unless of course you happen to be one of the poor misdiagnosed schmucks in that 20% group. “It’s not that  doctors lack sufficient clinical knowledge, but are rather tripped up by their biases,” writes Dr. Groopman.

Here’s how things can escalate once inaccurate bias comes into play. “Doctors are stumped by symptoms all the time,” explains Dr. Groopman, “By prescribing the wrong medication, for example, they often worsen the problem or even create a new one. Worse, misdiagnoses lead to an astounding 40,000-80,000 hospital deaths every year according to the American Medical Association, plus an uncounted number due to mistakes in the doctor’s office. Some 5% of autopsies find a condition missed by doctors that, if treated, might have saved the patient’s life.” Alarmingly, he describes the reality, actually researched at Johns Hopkins, that when doctors develop a dislike of a particular patient, they tend to shut down and close their minds. “It’s a set up for misdiagnosis - you do not get good care.” 

He uses the word ‘anchoring’ to describe one common form of misdiagnosis, and confesses his own telling example: as a young medical resident, he once made a hasty (and wrong) diagnosis of acid reflux for a female patient who presented with heart attack symptoms. In spite of her protests that his diagnosis wasn’t correct, the acid reflux diagnosis was now ‘anchored’ in his mind as he scooted her out the door.  Two weeks later, he was paged when the same woman was admitted to hospital for emergency cardiac surgery.

This example, incidentally, is frighteningly similar to my own initial misdiagnosis of acid reflux, despite presenting with textbook heart attack symptoms.  Like Dr. Groopman had, the ER doctor decided immediately that the problem was just acid reflux.  I was sent home from the ER, feeling very embarrassed, with instructions to ask my family physician for indigestion meds. Two weeks of increasingly debilitating symptoms followed (but hey! at least I knew it was not my heart!) until I too was admitted to hospital for emergency treatment of a newly revised diagnosis of ‘significant heart disease’.

Dr. Perri Klass is one doctor who actually did read How Doctors Think, and wants other docs to read it, too. 

“I wish I had read this book when I was in medical school,” says the professor of journalism and pediatrics at New York University. ”Every reflective doctor will learn from this book – and every prospective patient will find thoughtful advice for communicating successfully in the medical setting and getting better care.” 

Other errors occur when a patient is irreversibly classified with a particular syndrome, what Dr. Groopman calls “diagnosis momentum, like a boulder rolling down a mountain, gaining enough force to crush anything in its way.”

How Doctors Think is mostly about how doctors get it right, and about why they sometimes get it wrong.

For example, “attribution errors” happen when a doctor’s diagnostic cogitations are shaped by a particular stereotype. It can be negative, Dr. Klass explains, when doctors, for example, fail to diagnose an endocrinologic tumor causing peculiar symptoms in “a persistently complaining, melodramatic, menopausal woman who quite accurately describes herself as kooky.”

But positive feelings can also get in the way, too, Dr. Klass says. A hospital Emergency Department doctor misses unstable angina in a forest ranger because “the ranger’s physique and chiseled features reminded him of a young Clint Eastwood – all strong associations with health and vigor.”  In cardiac circles, we know that this kind of positive misdiagnosis is distressingly common.  For example, research tells us that one in every 50 heart attack patients (both male and female) is misdiagnosed and sent home from Emergency.  But if you’re a young woman suffering a heart attack, you are seven times more likely to be misdiagnosed and sent home. “You’re too young to have heart disease!”

Dr. Klass appreciated that the book’s patient stories are told with Dr. Groopman’s customary attention to character and emotion. “There is great care and concern for the sense of life-and-death urgency in analyzing the well-intentioned thought processes of the highly trained. I have never read elsewhere this kind of discussion of the ambiguities besetting the ‘superspecialized’ – the doctors on whom the rest of us depend.”

What is it with medical specialists that make them prone to these ‘ambiguities’? “Specialization in medicine confers a false sense of certainty,” claims Dr. Klass. “How Doctors Think helped me understand my own thought processes and my colleagues’ – even as it left me chastened and dazzled by turns.”

So what does Dr. Groopman recommend to patients like me who are faced with a diagnosis that just doesn’t make sense – like that acid reflux error? 

“Ask questions of that doctor!” he advises. “Like ‘What else could it be?’ (especially if the problem is not going away) or ‘Could two things be going on at the same time?’  (you can have both acid reflux and heart disease) or  ‘Is there any test result so far that might contradict your first impression?’

Stephen Dubner, author of Freakonomics, sums up his take on the book: “You’ll never look at your own doctor in the same way again – for better or worse.”