What’s New in the Patient Safety World
March 2013
Diagnostic Error in Primary Care
One of the
diagnostic errors we’ve talked about most frequently is the missed diagnosis
due to failure to follow up on test results. But is that the most frequent type
of error seen in primary care? If the source of statistics about diagnostic
error is primarily malpractice claims and settlements it might be the most
frequent type of error. But such data sources may be somewhat misleading. In
fact, a new study (Singh
2013) suggests it is not the most common diagnostic error in primary care.
Singh and colleagues
have just published a remarkable study on diagnostic errors in primary care
that is very enlightening. They used a trigger tool methodology (See our
Patient Safety Tips of the Week for October 30, 2007 “Using
IHI's Global Trigger Tool” and April 15, 2008 “Computerizing
Trigger Tools” and our What’s New
in the Patient Safety World columns for January 2011 “No
Improvement in Patient Safety: Why Not?” and May 2011 “Just
How Frequent Are Hospital Medical Errors?” on using the trigger tool
methodology). The triggers they used to identify cases for manual review were:
(1) a primary care index visit followed within 14 days by an unplanned hospital
admission and (2) a primary care index visit followed within 14 days by one or
more primary care visits, emergency department visits or urgent care visits.
Cases identified by these triggers were then manually reviewed by trained
experienced clinical reviewers for the occurrence of diagnostic errors. They
found diagnostic errors in 20.9% of cases identified by the first trigger and
5.4% identified by the second trigger, compared to 2.1% in control cases.
They found that
patients involved in cases with diagnostic errors were slightly older (66.5
years on average compared to 62.7 years). That should not be particularly
surprising. We know that, in general, medical errors tend to occur more often
in older patients probably as a result of a number of factors, including more
comorbidities, more medications, and other variables.
The diagnoses that
were “missed” were not “zebras” or relatively uncommon or complex diagnoses but
rather very common diagnoses and conditions (eg. pneumonia, decompensated CHF,
acute renal failure, cancer, UTI, etc.). That is similar to results of another
study on diagnostic errors in primary care (Ely
2012) that we discussed in our May
15, 2012 Patient Safety Tip of the Week “Diagnostic
Error Chapter 3”. The nature of the presenting symptoms was not
particularly remarkable with the exception that a significant number of
patients did not have a specific presenting complaint (eg. those presenting for
followup of their chronic conditions or those having a first visit to establish
ongoing care).
While breakdowns
were seen in all dimensions of the diagnostic process (and often involved more
than one dimension) breakdowns most often occurred during the
patient-practitioner clinical encounter and most often involved cognitive
errors in data-gathering or synthesis. These included items related to medical
history, physical exam, ordering diagnostic tests or failure to review prior
documentation. Interestingly, there was no documentation of differential
diagnosis in over 80% of cases with diagnostic errors. And another unintended
consequence of technology: they found that copying and pasting previous
progress notes was frequently associated with errors.
They also did find
errors related to referrals, failure to follow up on diagnostic tests and
interpretation of diagnostic tests.
The authors note
that their methodology, specifically the short time frame for the trigger
tools, likely biased the resulting types of errors toward more acute conditions
rather than more chronic conditions. Nevertheless, the study really shows that
diagnostic errors are very common in primary care visits and occur across the
broad spectrum of conditions seen in primary care practices.
The accompanying
editorial by Newman-Toker and Makary (Newman-Toker
2013) uses the statistics from the Singh study plus those from
autopsy-related studies on diagnostic errors to suggest that more than 150,000
patients per year in the US might have suffered misdiagnosis-related harm.
Singh and colleagues
make several salient points about interventions to prevent diagnostic errors. First,
given the wide variety of conditions and presenting symptoms they found in
their study it is very unlikely that focusing solely on specific presentations
will be successful in reducing overall errors. They note that most of the
breakdowns occurred in the clinical encounter, perhaps with time pressures and
short encounters contributing to inadequate decision making. Further yet they
note that the trend toward team care and the patient-centered medical home may
not result in the level of cognitive support needed for complex decision
making. And the current levels of technological decision support for diagnosis
are not readily available in most of today’s electronic medical records.
This is a really
good study that highlights both the frequency and breadth of the problem of
diagnostic error in primary care. It clearly points out how much needs to be
done going forward.
See our many prior Patient Safety Tips of the Week on diagnostic error:
· September 28, 2010 “Diagnostic Error”
·
November 29,
2011 “More
on Diagnostic Error”
·
May 15, 2012 “Diagnostic
Error Chapter 3”
· May 29, 2008 “If You Do RCA’s or Design Healthcare Processes…Read Gary Klein’s Work”)
· August 12, 2008 “Jerome Groopman’s “How Doctors Think”)
· August 10, 2010 “It’s Not Always About The Evidence”
·
January 24,
2012 “Patient
Safety in Ambulatory Care”
·
October 9, 2012 “Call
for Focus on Diagnostic Errors”
References:
Singh H, Giardina TD, Meyer AND, et al. Types and Origins of Diagnostic Errors in Primary Care Settings. JAMA Intern Med 2013; published online February 25, 2013
http://archinte.jamanetwork.com/article.aspx?articleid=1656540
Ely JW, Kaldjian LC, D’Alessandro DM. Diagnostic Errors in Primary Care: Lessons Learned. J Am Board Fam Med 2012; 25: 87–97
http://www.jabfm.org/content/25/1/87.full.pdf+html?sid=4db5c429-f3a7-4d3e-9488-8d9a15ed64eb
Newman-Toker DE, Makary MA. Measuring Diagnostic Errors in Primary Care. Comment on “Types and Origins of Diagnostic Errors in Primary Care Settings”. JAMA Intern Med 2013; published online February 25, 2013
http://archinte.jamanetwork.com/article.aspx?articleid=1656536
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