Medical Errors of Diagnosis
Harm More Than Treatment Mistakes
Another report on medical errors in America’s healthcare system cautions that these early-stage medical errors account for more medical harm – both preventable deaths and disability – than treatment errors.
In this study, Johns Hopkins researchers reviewed 25 years of medical errors – reflected in medical malpractice payouts – and found that diagnostic errors accounted for more payouts than surgical mistakes or medication overdoses.
Medical errors of improper diagnoses – missed, delayed and wrong diagnoses – accounted for the single largest proportion of such payouts at over a third. And twice as many occurred on an outpatient basis as among hospital inpatients, although the latter were more often lethal (48.4% vs. 36.9%).
The majority were missed diagnoses rather than delayed or wrong diagnoses – and the numbers are vastly understated because they only include those that led to malpractice claims. Most medical errors never reach the point of a malpractice claim.
Medical errors is a subject I address in-depth in Our Healthcare Sucks, including the following excerpts:
An estimated 15% of medical diagnoses are in error, with autopsy results showing diagnostic error rates in select areas up to 40%.…
According to an article in The New England Journal of Medicine: 
“125 million (Americans live) with chronic illness, disability, or functional limitation….
“The typical Medicare beneficiary saw two primary care physicians and five specialists (a) year…
“Patients with several chronic conditions may visit up to 16 physicians in a year.”
In a mostly seamless delivery system that emphasized and rewarded coordination of care and avoidance of redundant tests and procedures, maybe it would be possible to maintain quality despite such fragmentation of care.
But the U.S. medical delivery system is anything but “seamless” and, even if it were, it would still require a level of professional precision that’s sorely missing. Physician diagnostic error rates have been estimated as low as 5% (still 1 in 20) and as high as 40% based on autopsy results, with 15% the likely average ballpark.
That’s a huge margin of error that underscores the need to take what your doctor tells you with a grain of salt, at least until you’re able to get it confirmed by another opinion or by imaging or lab test results.
A special Supplement in The American Journal of Medicine  addressed this issue with a comprehensive review of the medical literature “Concerning teaching, learning, reasoning and decision making as they relate to diagnostic error and overconfidence”.
According to the authors of this review:
“Being confident even when in error is an inherent human trait, and physicians are no exception. When directly questioned, many clinicians find it inconceivable that their own error rate could be as high as the literature demonstrates…
“This reflects both overconfidence and complacency (emphasis added).”
An article on this report makes this dismal observation:
“Medical practitioners really do not use systems designed to aid their diagnostic decision making…physicians have underutilized decision-support systems and misdiagnosis rates remain high.”
Say It Ain’t So, Doc
Many patients don’t want to believe their doctors are capable of such high rates of medical misdiagnoses – any more than they want to believe our higher rates of medical errors than other developed countries. These are very intelligent, well-educated people, after all – generally more so than the patients they treat. How can such smart people make so many diagnostic errors?
The obvious answer lay in our fee-for-service payment system that penalizes doctors for spending the time required for thoughtful assessments and diagnoses. These “cognitive” services are reimbursed at far lower levels than procedures – whether needed or not.
Medicare and other payers are partly to blame for perpetuating this skewed payment system, as are those in the medical profession who choose to maximize their incomes at their patients’ expense. No one’s forcing them to submit to these skewed incentives, after all. Some don’t, so it’s not impossible – but they’re generally considered either saints or fools by their peers.
Anchoring On First Impressions
But there’s more to our excess medical errors than that. Dr. Jerome Groopman helps us understand how doctors’ training perpetuates mental shortcuts and crutches that contribute greatly to medical errors – and to diagnostic errors specifically. Here’s another excerpt from Our Healthcare Sucks on the subject:
Enter Dr. Jerome Groopman and his New York Times best seller, How Doctors Think, in which he lays out many of the sources of medical error, misdiagnosis, and misjudgment.
He helps us understand how such smart people can make so many mistakes by explaining that it’s not a function of intellect.
Instead, it’s a type of cognitive dysfunction in which many physicians – who are trained and required by their business mandates to make snap judgments – can fall prey to all sorts of errors in thinking.
Here are a few sentences from Dr. Groopman’s book that bear on this discussion:
“Misdiagnosis is different (from medical errors)…experts studying misguided care have concluded the majority of errors are due to flaws in physician thinking, not technical mistakes…
“In one study of misdiagnoses…some 80% could be accounted for by a cascade of cognitive errors…ignoring information that contradicted a fixed notion….
“As many as 15% of all diagnoses are inaccurate…
“Physicians tend to go with their first impression…
“The cognitive mistakes that account for most misdiagnoses…largely reside below the level of conscious thinking (emphasis added).”
Doctors, he explains, tend to get stuck on first impressions, something he calls “anchoring” because it anchors or fixates their diagnosis and often that of other doctors to whom you might be referred.
Or they just might not like certain patients, leading them to cut them off from fully describing their symptoms and settle for the most convenient or available treatment.
If they think the patient is a complainer or hypochondriac, they may assume a benign condition and minimize the likelihood of serious disease.
Now these cognitive flaws, as Dr. Groopman describes them, are all understandable as human failings – and Groopman quite understands them having labored with them himself – but are they professional?
Don’t patients have a right to expect more of their highly-paid doctors?
Why should patients have to worry about whether their doctor likes them or not and fear, quite correctly it seems, that it will bias their treatment?
This isn’t high school, after all.
Defensive Medicine is A Failed Response
The medical profession has failed to address this crisis in patient safety with the urgency it deserves – opting instead for defensive medicine practices intended to insulate them from malpractice liability rather than address medical errors head-on.
This defensive mindset prevents the profession from engaging more meaningfully to correct both diagnostic and treatment failures.
And with more patients seeking medical care as Obamacare is implemented, doctors will have even less time to spend with patients. The risk of diagnostic errors – and medical errors generally – is likely to increase as a result.
A thorough diagnostic work-up takes time and thought – both of which are in increasingly short supply in America’s broken healthcare system.
All of which means patients will have to learn how to protect themselves and their loved ones when engaging with our fundamentally flawed medical system.
 Coordinating Care – A Perilous Journey through the Health Care System, The New England Journal of Medicine, Vol. 358:1064-1071, 3/6/08.
 The American Journal of Medicine, Volume 121, Issue 5A, May, 2008.
 Elsevier Health Sciences (2008, April 29). Will You Be Misdiagnosed? How Diagnostic Errors Happen. ScienceDaily.
 How Doctors Think. Dr. Jerome Groopman, Houghton Miflin Company.2007.