Error Rates: Diagnosis--neither numerator nor denominator is known

Robert M Centor rcentor at UAB.EDU
Mon Dec 16 14:15:33 UTC 2013

While diagnostic errors are both the name of the meeting and the impetus
of the society, we should not ignore the road to diagnostic expertise.
Many diagnostic errors are really the mirror image of diagnostic
expertise.  We must help physicians become better diagnosticians, not by
berating them for errors, but by developing and explaining the path to
diagnostic success.  Pronovost succeeded because he showed others how to
have central lines without infections.  Of course he taught them to avoid
infections, but his work appeals to everyone because of success, not just
the absence of failure.

Robert M Centor, MD, FACP

Regional Dean, UAB Huntsville Regional Medical Campus
301 Governors Drive
Huntsville, AL 35801

Office: 256-539-7757
Fax: 256-551-4451

Chair-Elect, ACP Board of Regents

Professor, General Internal Medicine
FOT 720
1530 3rd Ave S
Birmingham, AL 35294-3407
Office: 205-975-4889

On 12/15/13, 10:32 PM, "Swerlick, Robert A" <rswerli at EMORY.EDU> wrote:

>While the issue of diagnostic error is the central focus of this
>organization, we continue to stumble when it comes to understanding
>frequency and definitions. We all know it exists and can identify
>specific examples within our own worlds but are hard pressed to come up
>with great approaches to measure.
>One of the strengths of the SIDM is the diversity of participants. It is
>also one of the weaknesses because the nature is diagnostic errors
>observed and/or experienced varies hugely across the spectrum of SIDM
>members. The is the inpatient/outpatient divide, the acute care/chronic
>care divide, urgent/non-urgent divide, and practitioner/patient divide. I
>also think there is a divide regarding under-diagnosis (missed diagnosis)
>vs. over-diagnosis often playing out in populations of patients who might
>be viewed as well (no symptoms).
>The priorities of these different constituencies may be very different
>and we may be best served by recognizing up front that the challenges and
>priorities and tools used to get at diagnostic errors in these scenarios
>will almost certainly be dramatically different. We may try to function
>in the same boat but we may not be able to all row in the same direction.
>The conceptual framework and tools used in the ICU will be very different
>from those used in the ambulatory setting. Those used in populations of
>patients who are sick (symptomatic) will be different from those who are
>ostensibly well.
>In the ambulatory setting perhaps one approach to get at frequency would
>be to look at patient reported outcomes and start with the premise that a
>portion of bad outcomes will come as a consequence of diagnostic error.
>With the deployment of CG-cahps questionnaires broadly, perhaps patient
>reporting can point us to where we should be looking? I do not see much
>hope for physicians to robustly recognize and report their diagnostic
>Robert A. Swerlick, MD
>> On Dec 15, 2013, at 3:10 PM, "Bradford Winters" <bwinters at JHMI.EDU>
>> In end we may need to measure the surrogates Mark describes for the
>>numerators. Actually counting them would be laborious even if we had a
>>clear way of flagging them. Plus the cultural resistance would be nearly
>>insurmountable. Surrogates would help get by that to some degree but we
>>need clear links between the surrogates and the diagnostic errors we can
>>measures. Perhaps making those links is the first step; choose some
>>straight forward ones like mi, pe bleeding and find surrogates that
>>predict them and move from there. Of course we never may be sure about
>>the predictive links to other diagnostic errors
>> Sent from my iPhone
>>> On Dec 15, 2013, at 10:48 AM, "Graber, Mark" <Mark.Graber at VA.GOV>
>>> The problem of not being able to count diagnostic errors is one that
>>>keeps me up at night.  Ross is correct in describing the fundamental
>>>challenges that arise in trying to establish the numerator.  If its
>>>true that 'you can't improve what you can't measure', that will leave
>>>diagnostic error at the starting gate.
>>> I've reluctantly come to accept the fact that he is correct - we
>>>really CAN'T measure every diagnostic error.  Its not like falls or
>>>wrong-site surgery, that are more easily tallied.  But .....  I believe
>>>it may be possible to establish a quantitative approach that's not as
>>>good as being able to count them all, but may suffice for advancing
>>>diagnostic science:
>>> *   If we use a specific definition and a defined methodological
>>>approach, we should be able to reproducibly count certain types of
>>>errors in certain settings.  Example:  delays in diagnosing colon
>>>cancer.  We will be able to measure the delays, even if we can't
>>>measure all the missed diagnoses
>>> *   If we focus on specific steps of the diagnostic process, we should
>>>be able to reproducibly count lapses in specific steps.  Example:  how
>>>many patients don't have a differential diagnosis listed on their
>>>chart;  How many critical alerts aren't addressed in a timely manner.
>>> Our efforts to reduce diagnostic error will be seriously stymied if we
>>>can't come up with at some ways to quantify the current state of
>>>affairs and see if interventions have any impact, in a quantitative
>>> Mark
>>> Mark L Graber, MD FACP
>>> Senior Fellow, RTI International
>>> Professor Emeritus, SUNY Stony Brook School of Medicine
>>> Founder and President, Society to Improve Diagnosis in Medicine
>>> ________________________________
>>> From: Ross Koppel <rkoppel at SAS.UPENN.EDU>
>>> Reply-To: Society to Improve Diagnosis in Medicine
>>><rkoppel at SAS.UPENN.EDU>
>>> Date: Wed, 11 Dec 2013 22:27:48 -0500
>>> Subject: Re: [IMPROVEDX] Error Rates: Diagnosis--neither numerator nor
>>>denominator is known
>>> The discussion on measurement of error and error rates is wonderful and
>>> thoughtful.
>>> What seems to be missing from much of this conversation, however, is
>>> that reality that we usually have no measures of the numerator -- the
>>> number of errors;  and we have an often slippery measure of the
>>> denominator-- number of diagnoses, number of correct diagnoses
>>> determined by case review and autopsies, number of correct diagnoses
>>> determined by a brighter doctor, number of correct dx when the patient
>>> was discharged (sic), number of med orders, number of med orders
>>> actually administered,  number of opportunities to order, number of
>>> patients, number of meds administered correctly, etc.
>>> Of course, the denominator and the numerator obviously differ by the
>>> measure on which we focus:
>>> Some errors are easy to spot, e.g.,  leaving hemostats in the thoracic
>>> cavity is a classic.
>>> Med prescription errors are very hard to know.  Patients are sick, old,
>>> have 5 comorbidities and are on 13 other meds.  Bad things happen when
>>> we do the right thing, good things happen when we do the wrong thing,
>>> polypharmacy is pandemic, what is ordered may not have been
>>> administered, no one knows the drug-drug-drug interactions among 13
>>> drugs, etc.     Case review is dependent on the right Dx (tautology
>>> alert) and knowing which tests to order, etc.
>>> And then we come to Dx errors. Again, some are easy, but, as
>>> demonstrated powerfully by this group's insightful conversation, many
>>> are profoundly hard to determine...especially in the first set of
>>> iterations.  Some may be impossible. Thus, the  discussion of error
>>> rates makes me cry for a massive dose of methodological caution and
>>> more humility.
>>> None of this is to say the discussion is neither productive nor
>>> exciting.  Of course not!  But the epistemological issues here are
>>> beyond most of the problems of science.  One of the reasons I so
>>> medical thinking is because physicians must deal with so many unknowns
>>> and uncertainties.  My colleague, Renee Fox, noted that one of the
>>> things we teach a young doctor is to distinguish between what he/she
>>> does not know and what Medicine does not know.  With diagnostic error,
>>> we have both of those factors plus the more vexing problem of what is
>>> knowable and what is knowable within the constraints of a specific
>>> patient's life and setting.
>>> Caveat: I'm not a physician, but I have spent the last 47 years focused
>>> on research methods, measurement of error, and statistics.
>>> Ross Koppel, Ph.D. FACMI
>>> Sociology Dept and Sch. of Medicine
>>> Senior Fellow, LDI, Wharton
>>> University of Pennsylvania, Phila, PA 19104-6299
>>> 215 576 8221 C: 215 518 0134
>>> Moderator: Lorri Zipperer Lorri at, Communication co-chair,
>>>Society for Improving Diagnosis in Medicine
>>> To unsubscribe from the IMPROVEDX list, click the following link:<br>
>>> <a 
>>> </p>
>>> Moderator: Lorri Zipperer Lorri at, Communication co-chair,
>>>Society for Improving Diagnosis in Medicine
>>> To unsubscribe from the IMPROVEDX list, click the following link:<br>
>>> <a 
>>> </p>
>> Moderator: Lorri Zipperer Lorri at, Communication co-chair,
>>Society for Improving Diagnosis in Medicine
>> To unsubscribe from the IMPROVEDX list, click the following link:<br>
>> <a 
>> </p>
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