Reducing Diagnostic Error
Tim Shoen, MD
Campaign for Quality
October 17, 2014
Disclosure
No financial interest to disclose
Thanks to Mark Graber, MD, President,
SIDM.
Sue Sheridan
Wall Street Journal
The Biggest Mistake Doctors Make
Misdiagnoses are Harmful and Costly
But they're often preventable
Laura Landro
November 17, 2013
Patient Safety Awareness 2014
Creating a world where patients and those that care for
them are free from harm.
www.npsf.org
Society to Improve Diagnosis in Medicine
We envision a world where diagnosis is
accurate, timely, and efficient.
www.improvediagnosis.org
Gregory House, MD
Objectives
• Review Incidence
• Contribution of Cognitive and
System factors
• Improvement Efforts
Diagnosis
The satisfaction of solving The
Riddle…is every doctor’s measure
of his own abilities; it is the most
important ingredient in his
professional self-image.
Dr. Sherwin Nuland
How We Die 1994
Human Error
• Skill Based
– error rate 1:1000
• Rule Based
– error rate 1:100
• Knowledge Based
– error rate 1:2
Preventable Harm
Error
Adverse
Event
Diagnostic Error
• Delayed Diagnosis
• Missed Diagnosis
• Wrong Diagnosis
Estimates of Dx Error Rate
Expert
Patient
Survey
Second
Reviews
Look backs
A. Elstein: 10-15%
One third relate a Dx error affected
themselves, family
Radiology and Pathology: 2-5% cancers
missed
30% of subarachnoid hemorrhage
misdiagnosed; 39% of dissecting AAA delayed
diagnosis; A third of neurological diagnoses
wrong or likely wrong
Autopsy
Major unexpected discrepancies that would
have changed the management are found in
10-20%
Estimates Diagnostic Error Rate
Trauma
8% of pts have missed injuries
General ER
.6% of 5000 admitted pts at Wayne State
MI
2-3% of pts sent home have an MI;
90% of pts admitted don’t have an MI or
ACS
Liability
47% claims high severity cases alleged
Dx related
Outpatient
Clinic
1:20 patients experience dx error each
year
Diagnostic Errors
• Are common and cause enormous
harm
• Estimates 40,000-80,000 annual
deaths
• Overlooked with emphasis on
system improvement
• Measurement tools lacking
Etiology of Diagnostic Error
Both System and
Cognitive Errors
46%
No Fault Error Only
7%
System Error Only
19%
Cognitive Error Only
28%
Cognitive Errors: 320
Faulty
Knowledge
3%
Faulty Data Gathering
14 %
Faulty Synthesis 83 %
Diagnostic Errors
• Are common and cause enormous
harm
• Most errors involve both system and
cognitive components.
• Cognitive errors most often reflect
problems using intuition
Cognitive Psychology
Brain
Hard wiring
Ambient conditions/Context
Task characteristics
Age and Experience
Affective state
Gender
Personality
RECOGNIZED
Patient
Presentation
Pattern
Processor
Dual Process Model of Clinical Reasoning
1
Pattern
Recognition
Repetition
NOT
RECOGNIZED
Education
Training
Critical thinking
Logical competence
Rationality
Feedback
Intellectual ability
2
Executive
override
Dysrationalia
override
Calibration
Diagnosis
Heuristic and Bias
• Confirmation Bias
• Availability
• Anchoring
COGNITIVE ERRORS
Most common:
•
•
•
•
Premature closure (39)
Faulty context generation (26)
Faulty perception (25)
Failed heuristic (23)
How can we make diagnosis
more reliable ?
Problems
•
•
•
•
Faulty context
Premature closure
Failed heuristic
Framing errors
Solutions
•
•
•
•
•
Consider the opposite
Crystal ball experience
Reflection
Be comprehensive
Learn the antidotes
DX Reasoning
The PROBLEM: COMPLEXITY
The SOLUTION:
NOT training; NOT redesign
A Checklist
The B-17, and its checklist, flew the next 1.8 million miles
without an accident. The military obtained over 13,000,
and the B-17 was the workhorse of the Allied air force in
World War II.
Complexity in Medicine
13,000 known diseases, syndromes, injuries
4,000 possible tests
6,000 medications, treatments, and surgeries
The average limits of human working memory:
7 discrete items
The Surgical Checklist
• WHO sponsored study in 8 countries
• 19 item checklist:
– Sign in + Time out + sign out
• Evaluated in 3733 operations:
• Results:
– Major complications fell from 11 to 7%
– Death rate fell from 1.5 to 0.7% (p = 0.003)
Haynes et al. NEJM 360: 491-9, 2009
A Checklist for Diagnosis
 Obtain YOUR OWN history
 Perform a focused, purposeful exam
 Take a “Diagnostic Time Out”
 Was I comprehensive ?
 Did I consider the inherent shortcomings of using my
intuition (heuristics) ?
 Was my judgment affected by bias ?
 Do I need to make the diagnosis now or can it wait ?
 What’s the worst case scenario?
 Embark on the plan, but ENSURE FOLLOW-UP & FEEDBACK
Structured Reflection
V ascular
I nfections & intoxications
T rauma & toxins
A uto-immune
M etabolic
I diopathic & iatrogenic
N eoplastic
C ongenital
C onversion (psychiatric)
D egenerative
E ndocrine
Possible Solutions
• National Agenda
• Research
• Health IT
• Clinical Reasoning Education
Summary
• Diagnosis errors are common and
harmful
• High quality healthcare requires high
quality diagnosis
• Diagnostic errors are costly
• Healthcare Organizations are well
positioned to lead efforts to reducing
these errors
Case Studies
• Maine Medical Center
– Physician Reporting
• SoCal Kaiser Permanente
– Electronic Records to Trace Diagnostic
Error
Reference
Reference
Questions?
Tim Shoen, MD
shoen7754@aol.com
Subject: Dx Error