Why diagnostic errors don't get any respect and what can be done about it

By Bob Wachter

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 said, 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 because diagnostic errors comprised 17 percent of the adverse events in the Harvard Medical Practice Study (from which the IOM’s 44,000 to 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. Think about the patient safety issues that are on today’s public 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 in the spot 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 Suitable to Create Sound Bites
These are great sound bites (I’ve used them many times myself):

    * “The average hospitalized patient experiences one medication error a day.”
    * “The average ICU patient has 1.7 errors per day in their care.”

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 percent 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 analysis, 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 Jerome 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. For until we do, we face a fundamental problem: a hospital can be seen as high quality hospital – receiving awards for being a great 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.