Why Diagnostic Errors Don’t Get Any Respect… And What Can Be Done About It

I gave a keynote yesterday to the first-ever meeting on “Diagnostic Error in Medicine.” I hope the confab helps put diagnostic errors on the safety map. But, as Ricky Ricardo would say, the experts and advocates in the audience have some ‘splainin’ to do.

I date the origin of the patient safety field to the publication of the IOM report on medical errors (To Err is Human) – it is the field’s equivalent of the Birth of Christ (as in, there was before, and there is after). But from the get-go, diagnostic errors were the ugly stepchild of the safety family. I searched the text of To Err… and found that the term “medication errors” is mentioned 70 times, while “diagnostic errors” appears twice. This is interesting, since diagnostic errors comprised 17% of the adverse events in the Harvard Medical Practice Study (from which the IOM’s 44,000-98,000 deaths numbers were drawn), and account for twice as many malpractice suits as medication errors.

What I call “Diagnostic Errors Exceptionalism” has persisted ever since. Just consider the patient safety issues that are on the public’s radar screen (i.e., they are subject to public reporting, included in “no pay for errors,” examined during Joint Commission visits, etc.). It’s a pretty diverse group, including medication mistakes, falls, decubitus ulcers, wrong-site surgery, and hospital-acquired infections. But not diagnostic errors. Funny, huh?

There are lots of reasons for this. Here are just a few:

The Problem of Visceral, Accessible Dread
Ask any horror movie producer – certain calamities cause visceral dread. They tend to be “bolt out of the blue” events – ones that lack both forewarning and opportunities for post-strike redemption. (Think sharks, plane crashes, tsunamis, and earthquakes.) But diagnostic errors often have complex causal pathways, take time to play out, and may not kill for hours (missed MI), days (missed meningitis) or even years (missed cancers). They don’t pack the same visceral wallop as wrong-site surgery, the “shark bit off a guy’s leg” of the safety field.

Iconic, Mediagenic Examples
Think about the errors that have made 60 Minutes in the past decade or so: the chemotherapy error that killed Boston Globe health columnist Betsy Lehman, the Duke transplant mix-up involving failure to check ABO type, the amputation of Willie King’s wrong leg, even Dennis Quaid’s twins’ heparin OD. How about diagnostic errors? Personally, I can’t think of one that ended up under the klieg lights. The one mediagenic error that was (at least in part) due to a diagnostic error – the death of Libby Zion at New York Hospital in the 1980s – was framed as a death caused by long residency work hours and poor supervision, not as one caused by a diagnostic error.

Data That Are Suitable For Sound Bites
These are great sound bites (I’ve used them many times myself):

We have no comparable data for diagnostic errors, and so they don’t compete very well for attention. In fact, this measurement problem (diagnostic errors are very hard to measure, particularly through retrospective chart review) is a huge issue – how are we to convince policymakers and hospital executives, who are now obsessing about lowering the rates of hospital-acquired infections and falls, to focus on diagnostic errors when their toll is so vague?

Some Research (or at Least Common Sense) Points to Solutions
Many traditional types of errors can be paired with well-understood solutions, some of which even have data demonstrating that they work. Just consider these:

  • Prescribing errors: computerized order entry
  • Drug administration errors: bar coding and smart pumps
  • Failure in rote processes: double checks, checklists
  • Wrong-site surgery: sign the site
  • Retained sponges in surgery: count ‘em up

The solutions for diagnostic errors generally fall into two big buckets. One might be thought of as “better thinking”: appreciating the risks of certain heuristics (“anchoring”, “premature closure”), correctly applying Bayesian reasoning and Iterative Hypothesis Testing, and so on. This group of activities, while fascinating (building on the groundbreaking work of brilliant cognitive psychologists like Amos Tversky and Daniel Kahneman), is a bit too arcane for real people to get their arms around. It seems like Inside Baseball.

The other broad bucket of proposed solutions to diagnostic errors involves various forms of computerized decision support. Providing computerized diagnostic support – and perhaps even some artificial intelligence (AI) – at the point-of-care makes all the sense in the world. But remember the Technology Hype Cycle from a few blogs back. Diagnostic AI was way overhyped in the 1970s and 80s, much of the hype focused on several programs that titillated the IT wonks of the day (such as QMR and Iliad) but are now in the IT dustbin of history. Turns out that replacing a doctor’s diagnostic abilities with a computer is an incredibly knotty problem (partly because the symptoms, signs, and initial labs in flu and plague have about 95% overlap). The disappointment over the ineffectiveness of early AI programs led to widespread skepticism that any decision support programs could help physicians be better diagnosticians. This skepticism is getting in the way of today’s markedly improved systems, such as Isabel, from gaining the traction they deserve.

So solutions for diagnostic errors – whether new ways of training people to think or computerized decision support – do not compete very effectively in the battle for resources and attention against far more easily implemented and better researched solutions to other safety problems, such as “bundles” to prevent catheter infections or ventilator-associated pneumonia.

The Problem of the Accountable Entity
One final problem is the absence of an accountable entity with deep pockets. Because the patient safety field focused its attention on hospital errors (at least initially), the hospital – rather than individual physicians – could be held accountable (by the Joint Commission, CMS, the state, and the media) for creating safer systems. And hospitals have stepped up to this particular plate, by putting safety atop their strategic plans, and by implementing incident reporting systems, patient safety officers, CPOE, root cause analyses, teamwork training, and more. They had no choice.

But if diagnostic errors are seen as individual physician cognitive problems, then the hospital is unlikely to contribute to their solution, or even to pay much attention to them. And so they haven’t, and they don’t.

What Can Be Done?
Is there any hope of getting diagnostic errors included under the broad umbrella of patient safety, where they can garner the attention and resources they deserve? Sure. But we need to solve a chicken-or-egg problem: if there is no interest and funding in the topic, we won’t generate the research we need to measure the toll of the problem or come up with effective solutions. And then there won’t be funding and interest.

That’s why AHRQ’s sponsorship of the Diagnostic Errors Conference, and the agency’s overall interest in the topic, is so crucial. Having allies in high places, beginning with AHRQ and other funders, but extending to malpractice carriers, accreditation boards, med schools and residencies, and even the Joint Commission, will be essential.

Judging by the robust sales of Groopman’s book, How Doctors Think, the public is interested in this topic. Passionate and effective leaders and advocates, most of whom were in Phoenix yesterday, are emerging. If we can find some support for their work, better data and solutions cannot be too far behind. And then the problem of diagnostic errors will get the attention it deserves.

As the quality and safety movements gallop along, the need to fix Diagnostic Errors Exceptionalism grows more pressing. Until we do, we will face a fundamental problem: a hospital can be seen as a high quality organization – receiving awards for being a stellar performer and oodles of cash from P4P programs – if all of its “pneumonia” patients receive the correct antibiotics, all its “CHF” patients are prescribed ACE inhibitors, and all its “MI” patients get aspirin and beta blockers.

Even if every one of the diagnoses was wrong.


  1. menoalittle on June 3, 2008 at 3:43 am


    Your insight is always appreciated. Diagnostic errors will proliferate with health IT (EMR, CPOE, MDDS) pervading the practice of medicine, This is the government mandated solution to the ills of American medical care. The care of the patient has been altered and diagnostic medicine is endangered. These untested and oft flawed devices result in cognitive disruption and cause a depletion of and diversion of intellectual energy from the patient to the device. Clinical training for residents is diluted. There is a dependence on paraprofessionals to do the clicking, order entry, and note writing as if these activities are meaningless for the clinicians’ intellectual abstraction needed to correctly evaluate, diagnose, and treat.

    In your post of January 27, you report the disappearance of radiology rounds. In your post of January 31, you report “losing that magical interdisciplinary opportunity” as a result of IT enabled medical practice at a distance. Provocative cognitive processes are key to creative diagnosis. The medical care environment is now controlled and altered by complex systems of health IT devices designed by those unfamiliar with the diagnostic needs of clinicians. Diagnostic errors will increase as an effect of technology diverting attention from the patient. The clinician is working for the device rather than vice versa.

    Dr. Groopman, to whom you referred in this post, wrote a commentary together with Dr. Harztband, entitled “Avoiding the Pitfalls of Going Electronic” (NEJM 358:16, 1656). They comment that the EMR becomes “a powerful vehicle for perpetuating erroneous information, leading to diagnostic errors that gain momentum when passed on electronically.” They report “chart review during rounds has become nearly worthless,” that patients “during their 15-minute clinic visit watch their doctor stare at a computer screen, filling in a template,” and they report the increasingly common cut and past phenomena of EMR facilitated “clinical plagiarism” of progress notes that, according to the authors, distract from physicians’ cognitive work. Clinicians cannot find the data they need, when needed, in the health IT device associated “Where’s Waldo” scenario. The wheat cannot be easily separated, as they say, from the chaff.

    With this brave new world medical care experiment of the government, by the government, for the government, developed by companies, for the companies’ and hospitals’ profits, we are witnessing the dumbing industrialization and automation of medical care. Diagnosis? What, me worry?

    Best regards,


  2. Healthcare Provider on June 5, 2008 at 6:47 pm

    I agree that diagnostic errors are a big problem in many cases. Having had my own experience of a mildly ill family member’s blood work being resulted with someone else’s results, and the major upset it caused in our family thinking that our young, healthy child had acute kidney failure, I thought immediately your article would include that sub-topic. These errors in diagnostic results do not happen often, but when they do the impact can be emotionally devastating and very costly until the error is realized or repeat test results are available. I have not read anything about the subject in the literature. It would be interesting to explore the frequency of such errors and their cost in otherwise uneccessary testing or interventions. I wonder how many labs would provide the transparency necessary to allow meaningful data to be collected.

  3. Freya Koss on June 19, 2008 at 4:46 pm

    MISDIAGNOSIS, Tragedy of medical profession
    Amalgam Dental Fillings = Mercury Poisoning

    Dear Bob,


    A huge percentage of the population has been misdiagnosed and labeled with a plethora of illnesses including from autoimmune , neurological, mental and endocrine diseases. Unfortunately, the medical profession has not be taught about the adverse effects of chronic exposure to mercury from amalgam dental fillings. Amalgam fillings are 50% mercury, a known neurotoxin, which is released from commonly used silver amalgam fillings for the duration of the filling in the tooth. It is inhaled and ingested and has the potential of disrupting every organ and function in the body. Mercury is a hazardous risk to health and he environmental, and is being removed from medical devices (vaccines included) and various other products due to health and environmental risk. Dental fillings are no different, in fact, the World Health Organization concluded in 1991 and again in 2005 that mercury from dental fillings is the largest exposure of mercury to humankind.(Mercury Policy Report and graph available).

    I am one of millions who was misdiagnosed by several neurologists when I was suddenly struck with double vision and diagnosed with Multiple Sclerosis, Lupus and then Myasthenia Gravis in 1998. I was told that I would be sick for the rest of my life, that steroids would fix my eyes, and that there was no known etiology for these diseases. Understanding that one does not develop MS in a day, I was determined to find out what had caused the “autoimmune” symptoms. Within five days of research I discovered that I had been poisoned by mercury during a dental procedure seven days prior to the
    onset of symptoms. I had had an old amalgam filling removed and a new one placed.

    The doctors misdiagnosed me, labeling me with MS, Lupus and Myasthenia Gravis all life threatening diseases. If I had followed these recommendations, I would have been sick for the balance of my life and most probably n a wheel chair by now. Instead, I had my fillings removed slowly by a mercury-free dentist, changed my diet, took hundreds of nutritional supplements and recovered. My story can be read at: http://www.toxicteeth.org.

    The crime is that the dental profession has not been honest with the medical profession, about the dangers of mercury fillings and the doctors are not taught about the effects of mercury exposure from dental fillings. At a 2006 FDA Scientific Panel Review of the dangers of mercury fillings, Dr. Lyn Goldman pediatrician and an environmental epidemiologist.at John Hopkins Bloomberg School of Medicine testified:
    DR. GOLDMAN: Yes. I mean, I think it’s important to understand, in terms of the way the clinical world has looked at this issue, that I mean, I’ve been involved in a number of exercises to come up with just environmental history questions for physicians to use, and triggered by different indications, and most of us were taught, I was certainly taught that exposure to mercury from amalgam is minimal, and that one shouldn’t think about mercury toxicity from amalgam.
    I have never included a question about recent dentistry on an environmental exposure questionnaire that I’ve worked on. It’s never been suggested.
    Now I will have to say there is something-I was recognizing this, and I appreciate your asking that question, because [U1]there is something that’s happened in the last couple of days in these discussions, to kind of at least move me a little bit further over into being a little more concerned than I was before, and I will tell you the two things that concern me.
    One is that some of these exposure data, the range of exposures then–and there is a lot of new science, even though the white paper kind of implies there’s not. But then it uses the studies, and there are a lot of new studies that do show, that do document an association between, you know, amalgam and levels of mercury in urine, and more than I would expect, given what I was taught. And I’m sure that that’s true for the others who were taught what I was taught, because we were all taught that at one point.
    And so I’m taking it more seriously, that there could be exposures, A. Two, that there could be acute exposures and that there could be symptoms associated with that, and that maybe it is worth inquiring about whether there’s symptoms. We haven’t done that inquiry, and I just took a quick look at PubMed, just to see, you know, if someone’s published on that question, and there are no publications, other than, you know, the Kingman study included a question about tremor in the questionnaire, and that’s about it.
    You know. So I think this is an area where I don’t think we can make a conclusion based on the literature, you know, it’s kind of silent, but I will say on an indirect basis, I am more concerned about this today than I was last week. Whatever that means.

    This entire passage articulates the lack of awareness by the medical professionals to consider dental amalgam” mercury” related effects. This is very telling considering Dr Goldman’s professional history, including work at the EPA. She is in a leading university medical school and reveals that dental amalgam exposure is not factored into consideration. Just how damaging is ADA propaganda re safety in dental amalgam? The proximate cause of injury might be considered the reliance on erroneous data in order to protect egregious egos.

    I commend you for bringing the issue of “misdiagnosis” to the attention of the medical profession and the general public.

    For more information on the symptoms and illnesses related to mercury toxicity:
    http://www.iaomt.org, http://www.toxicteeth.org, http://www.amalgam.org.

    Freya Koss
    [email protected]

    Posted by: Freya Koss | June 19, 2008 at 09:34 AM

  4. MikeP-QMD on July 2, 2008 at 8:23 pm

    Hi Bob. I agree wholeheartedly that diagnostic error is probably the iceberg below the tip of patient safety. Confidence and judgment are two human factors that are often either ignored or are “engineered out” of quality and safety solutions. I’ve heard from many, many physicians that the competing pressures from payers (“don’t spend too much”) and risk underwriters (“don’t miss anything”) have created a crisis in confidence and judgment in the profession.

    In 1994, I heard Professor Stephen Hawking speak at MacWorld, the annual convention of the MacIntosh engineering community. In his keynote, Dr. Hawking impressed upon these gadget-makers that their work in building technological infrastructure for sharing information would soon be accelerated by the “internet” and would result in an explosion of information never before experienced by humans. His message was that “information overload” has very real effects on people, specifically their ability or inability to organize and make sense of too much information. The byproduct, he warned, was that information overload elicits very primal human reactions–anger, confusion, frustration, indecision, even violence.

    The sheer volume of information available to inform a physician’s diagnostic judgment, combined with the mounting consequences of getting it wrong, suggests it’s a bad time to ignore the importance of diagnostic errors.

  5. Stagnaro Sergio on November 25, 2008 at 1:32 pm

    I find the conclusion really highlightening our problem: “Until we do, we will face a fundamental problem: a hospital can be seen as a high quality organization – receiving awards for being a stellar performer and oodles of cash from P4P programs – if all of its “pneumonia” patients receive the correct antibiotics, all its “CHF” patients are prescribed ACE inhibitors, and all its “MI” patients get aspirin and beta blockers”. As a matter of fact, such as statement indicates that all around the world physicians know exclusively EBM, Evidence B(i)ased Medicinne. In a few words, All individuals are created equal! Really, nowadays, beside EBM it does exist also SPBM, Single Patient Based Medicine (See for instance . Stagnaro Sergio. Single Patient Based Medicine: its paramount role in Future Medicine. Public Library of Science. 2005.http://medicine.plosjournals.org/perlserv/?request=read-response).
    To Err…is human, of course. However, it is true also that today’s Medicine is ruled by economics. Meeting a “single” patient, doctor who knows ALL patient’s biophysical semeiotic constitutions “and” inherited Real Risk, is facilitated in making rapidly the correct diagnosis, which come always before the correct therapy. However, spreading the knowledge that ONLY individuals with diabetic, aterosclerotic, osteoporotic, hypertensive, oncological, a.s.o., constitution, may be involved by Diabetes, and respectively by CAVD, osteoporosis, hypertension, and finally CANCER, a.s.o., IS NOT politically correct. As a consequence, avoiding n apochal revolution, only free, farsighted,open-minded Editors publish these advances of Medicine, as do Nature Editors:www.nature,com, About Biophysical Semeiotic Constitutions
    http://www.nature.com/news/2008/081010/full/455845a.html http://blogs.nature.com/news/thegreatbeyond/2008/11/whos_in_charge_of_science_unde.html#comments
    And Bob Wachter?

  6. Bob Wachter on September 7, 2010 at 4:42 pm

    FYI, my article on this issue (a more robust discussion of the place of diagnostic errors in the patient safety world) appears in this month’s issue of Health Affairs:


    And the New York Times covered it today in their Prescriptions Blog:


  7. […] was entitled, “Why diagnostic errors don’t get any respect” (I wrote up the speech in my blog and a Health Affairs article, […]

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