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

Graber, Mark Mark.Graber at VA.GOV
Mon Dec 16 00:09:45 UTC 2013


Brad - can you give us a concrete example of a surrogate and the kind of linkages you're thinking about ?  Seems like a promising approach.


________________________________
From: Bradford Winters <bwinters at jhmi.edu>
Date: Sun, 15 Dec 2013 15:08:44 -0500
To: Society to Improve Diagnosis in Medicine <IMPROVEDX at LIST.IMPROVEDIAGNOSIS.ORG>, "mark.graber at va.gov" <mark.graber at va.gov>
Cc: <IMPROVEDX at LIST.IMPROVEDIAGNOSIS.ORG>
Subject: Re: [IMPROVEDX] Error Rates: Diagnosis--neither numerator nor denominator is known

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> wrote:
>
> 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 sense.
>
> 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 <IMPROVEDX at LIST.IMPROVEDIAGNOSIS.ORG>, Ross Koppel <rkoppel at SAS.UPENN.EDU>
> Date: Wed, 11 Dec 2013 22:27:48 -0500
> To: <IMPROVEDX at LIST.IMPROVEDIAGNOSIS.ORG>
> 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 even
> 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 respect
> medical thinking is because physicians must deal with so many unknowns
> and uncertainties.  My colleague, Renee Fox, noted that one of the first
> 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 ZPM1.com, Communication co-chair, Society for Improving Diagnosis in Medicine
>
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>
> Moderator: Lorri Zipperer Lorri at ZPM1.com, Communication co-chair, Society for Improving Diagnosis in Medicine
>
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