Checklists to Reduce Diagnostic Errors John W. Ely, MD, Mark L. Graber, MD, and Pat Croskerry, MD, PhD
evaluation. The purpose of this article is
often be traced to physicians’ cognitive
to argue for the further investigation and
describes three types of checklists: (1) a
revision of these initial attempts to apply
general checklist that prompts physicians
checklists to the diagnostic process. The
to optimize their cognitive approach, (2)
basic idea behind checklists is to provide
to error, but little is known about how to
a differential diagnosis checklist to help
an alternative to reliance on intuition and
of diagnostic error—failure to consider
the correct diagnosis as a possibility, and
Editor’s Note: A commentary on this article appears
they are well integrated in the workflow,
Cognitive Processes in Diagnosis
suggestions include reflective practice8,9
recognize flaws in the intuitive “thinking”
psychology related to the “dual-process”
1).18 This model proposes two basic modes
and more likely to result in patient harm
than are other types of medical errors.3,4
Given their success in other settings, it is
reflexive, intuitive, and may operate at a
subconscious level. We perform many tasks
might help reduce diagnostic errors.
Checklists are used by airline pilots in all
system-based problems are relatively easy
routinely until the crash of a Boeing 299
they are repeated on a regular basis, these
release the elevator locks.11 Checklists are
subconscious level, and if everything is as it
Dr. Ely is professor, Department of Family Medicine, University of Iowa, Iowa City, Iowa.
used by other high-risk, high-reliability
seems, we perform well. In contrast, Type 2
processes are analytic, slow, and deliberate. Dr. Graber is chief of medicine, Department of
Veterans Affairs Hospital, Northport, New York, andprofessor and associate chair, Department of Internal
Medicine, State University of New York, Stony Brook,
Dr. Croskerry is professor of emergency medicine,
Dalhousie University, Halifax, Nova Scotia, Canada.
intensive care unit staff use checklists to
Correspondence should be addressed to Dr. Ely,
Department of Family Medicine, 01291-D, PFP,
clinical situations that seem familiar, we
University of Iowa Carver College of Medicine, 200
Hawkins Drive, Iowa City, IA 52242; telephone:
(319) 384-7533; fax: (319) 384-7822; e-mail: john-
surgical deaths by half after introducing a
checklists prove effective. For diagnosis,
The purpose of this article is to describe a
generic checklists could force a reflective
First published online January 18, 2011doi: 10.1097/ACM.0b013e31820824cd
potential role for checklists in avoiding
check, and specific checklists could force
Supplemental digital content for this article isavailable at http://links.lww.com/ACADMED/A38.
Academic Medicine, Vol. 86, No. 3 / March 2011
“upstream” problems—those involving
previous encounters—such assuccumbing to the framing bias imparted
RECOGNIZED reflexive) Processes
it is proposed and communicated, to theextent that subsequent physicians may
Calibration† Diagnosis
discount or fail to consider other possible
Processor
“groupthink,” in which the chances oferror increase when the impressions of
RECOGNIZED analytic) Processes Figure 1 A model for diagnostic reasoning based on dual-process theory. Adapted with
permission from Croskerry P. A universal model for diagnostic reasoning. Acad Med. 2009;84:1022–1028. Type 1 thinking can be influenced by multiple factors, many of them subconscious
Perform a focused and purposeful
(emotional polarization toward the patient, recent experience with the diagnosis being
physical exam. The initial hypotheses
considered, specific cognitive or affective biases), and is therefore represented as multiple-
channeled, whereas Type 2 processes are, in a given instance, single-channeled and linear. Type 2override of Type 1 (executive override) occurs when physicians take a time-out to reflect on their
thinking, possibly with the help of checklists. In contrast, Type 1 may irrationally override Type 2
(dysrationalia override) when physicians insist on going their own way (e.g., ignoring evidence-
based clinical decision rules that can usually outperform them).
special attention. However, we must alsolook for signs that might suggest alternate
* “Dysrationalia” denotes the inability to think rationally despite adequate intelligence.68† “Calibration” denotes the degree to which the perceived and actual diagnostic accuracy correspond.
Checklists could help us resist the biases
errors in hospitals, clinics, and emergency
Generate and differentiate initial hypotheses with further history, physical exam, and diagnostic tests.
insultingly obvious (e.g., “Obtain your
improving diagnostic reasoning.2,10 Using
own complete history”), but their routine
problems related to diagnostic testing,26
for most physicians. After all, pilots no
their copilots to release the elevator locks.
• consider a comprehensive differential
The general checklist
posttest period, occurring at rates of 10%
reproducible approach to diagnosis.21 List
1 offers an example of such a checklist.
• develop strategies to avoid predictable
Pause to reflect—take a diagnostic “time-out.” Short of seeking a second
• recognize our altered mood states that
arise from fatigue, sleep deprivation, or
plausibility of the working diagnosis may
be our best tool to avoid error.8,9 The two
context errors and premature closure.5,26
Context errors arise when a critical signalis distorted by the background against
Diagnostic Checklists Obtain your own complete medical
which it is perceived.24 A typical context
Here, we describe three types of checklists
history. There is no substitute for
Academic Medicine, Vol. 86, No. 3 / March 2011
Table 1 Cognitive Biases and Failed Heuristics Addressed by Diagnostic Checklists Bias or heuristic Definition* Role of checklist
The tendency to perceptually lock on to salient features
Prompt physician to consider diagnoses other than the
of the patient’s presentation too early in the diagnostic
process and failing to adjust this impression in light oflater information.
The disposition to judge things as being more likely or
Prompt physician to consider diagnoses other than
frequently occurring, if they readily come to mind.
The tendency to ignore the true prevalence of a
Remind physician of the relative prevalence of diseases
disease, either inflating or reducing its base rate and
in primary care for the patient’s complaint.
The decision-making process ends too soon; the
Prompt physician to reopen the diagnostic process and
diagnosis is accepted before it has been fully verified.
consider alternative diagnoses before discharging the
“When the diagnosis is made, the thinking stops.”
The physician looks for prototypical manifestations of
Prompt physician to consider causes for the symptoms
disease (pattern recognition) and fails to consider
other than the ones that readily fit the pattern.
The tendency to call off a search once something is
Prompt physician to consider additional causes of the
The failure to elicit all relevant information in
Prompt physician to ask questions that might confirm
establishing a differential diagnosis.
The critical signal is distorted by the background
Encourage physician to rethink assumptions and
* Source: Croskerry P. Cognitive and affective dispositions to respond. In: Croskerry P, Cosby K, Schenkel S, Wears
R, eds. Patient Safety in Emergency Medicine. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:219 –227.
other decisions may take priority, such as
patient’s presentation often changes over
Differential diagnosis checklists
diagnostic errors is our failure to consider
and write “NYD” (not yet diagnosed) in
• Consider the opposite: “Why can’t this
be something else?” Tests that rule out
diagnostic label until our certainty is high
• Use “prospective hindsight”: Derived
Embark on a plan, but acknowledge Proposed General Checklist for Diagnosis uncertainty and ensure a pathway for follow-up.37,38 We often just play the
• Obtain your own complete medical history.
• Perform a focused and purposeful physical
Certainty is not a realistic possibility. The
correct diagnosis often emerges over time
as test results become available or as the
differentiate these with additional history,
patient’s symptoms and signs evolve. This
physical exam, and diagnostic tests.
• Apply decision support tools: A growing
longitudinal aspect of diagnosis mandates
• Pause to reflect—take a diagnostic “time
that we reconsider an initial diagnosis at
diagnosis generators are available, such as
⅙ Was my judgment affected by any other
uncertainties, and lay out a concrete plan
⅙ Do I need to make the diagnosis now, or
ensuring follow-up is a strategy that can
help improve the reliability of diagnosis
uncertainty and ensure a pathway for
Academic Medicine, Vol. 86, No. 3 / March 2011
highlighted in List 2 and detailed in the
dizziness, and so on. The checklists were
revised during two years of use in clinic.
to consider a comprehensive list of causes
of the differential diagnosis checklist is
differential diagnosis checklists, but one
of the authors (J.E.) has noted anecdotal
checklists highlight diagnoses that should
not be missed and those that are, in fact,
checklists in practice. For example, a 90-
anatomy,43,45,46,48 pathophysiology,41,45
after two albuterol nebulizer treatments,
dyspnea. She had been seen four daysearlier with a “COPD exacerbation” and
Example of Differential Diagnosis
to cover 100% of presenting complaints. Checklist Sinus tachycardia
checklists. And within each checklist, our
goal was to cover at least 99% of patients
• Chronic obstructive pulmonary disease
• Pregnancy (10 to 20 beats per minute at
such as constipation and breast lumps.
that did not alter the initial diagnosis and
withdrawal, bupropion, caffeine, cilostazol,
cocaine, ephedrine, epinephrine,isoproterenol, nicotine, tobacco)†
Cognitive forcing checklists for specific diseases
“pneumococcal pneumonia,” “klebsiella
Checklists can serve as cognitive forcing
“right-upper-quadrant pain,” “right-
because we wanted to avoid redundancy.
until the card is removed. Thus, the error
avoided. If the checklist is always built
into diagnostic thinking, then it becomes
generic or specific. In the generic sense,
“ROWS” (rule out worst-case scenario)
• Postural orthostatic tachycardia syndrome
possibilities always receive consideration.
• Chronic nonparoxysmal sinus tachycardia
checklist at the time of admission to help
In the specific sense, checklists may help
determine whether further history taking,
avoid predictable pitfalls for particular
* “Don’t-miss” diagnosis. † Commonly missed diagnosis.
Academic Medicine, Vol. 86, No. 3 / March 2011
address treatment rather than diagnosis. Example of a Disease-Specific Cognitive Forcing Checklist Ankle injury
enough face validity to make such testing
questioned the ethics of allowing patients
to participate in a usual-care arm (i.e., no
safety intervention) in clinical trials of
⅙ Peroneal tendon syndromes (tendinitis,
checklists before adopting them. Instead,
most likely for a particular patient.
⅙ Consider stress films for ankle stability
not been widely adopted in practice,52,53
checklists may have a greater potential for
harm than preflight or surgical checklists.
knowledge base,6 they can be difficult to
For example, they could lead to excessive
incorporate into the workflow,6,54–56 and
consultation or needless testing (although
most serious errors result from doing too
Other interventions similar to checklists
⅙ Missed neurovascular injury (suspect if
⅙ Missed associated fracture (especially
(mental checklists).62 These interventions
learned not to rely on their memories. In
contrast, physicians value superior recall
⅙ Missed Maisonneuve fracture (proximal
organizational structures that differ from
⅙ Missed Achilles tendon rupture (partial or
than mental crutches, reflective thought,
Limitations of checklists
⅙ Missed complex regional pain syndromes
Recent success in adapting preflight-style
stories, but they don’t make great health
checklists for diagnosis may be a “bridge
too far.” The analogy between actionable
forcing strategies will inevitably focus on
intensive care units, or even airplanes.
procedures in diagnosis is not tight. Thoughts are less tangible than actions,
Checklists could produce a false sense ofreassurance that leads to complacency,
Further Considerations and Cautions
whether they have been completed. Inboth medical and nonmedical settings,
checklists are read aloud by teams rather
checklists as a concept that might reduce
aspects of care unrelated to diagnosis.
diagnosis is usually silent, lonely work,
Similar concerns were raised with clinical
and a natural pause point11 to review the
algorithms. It was feared that physicians
kinds of checklists, which we have used in
checklist, such as before takeoff or before
data to support these concerns whenalgorithms were studied in practice.65,66
Related studies
Diagnostic support tools include practice
checklists in this article were not derived
affective state. But rather than unfocused
Academic Medicine, Vol. 86, No. 3 / March 2011
“thunderclap” headache, “worst-ever”
12 Karl R. Briefings, checklists, geese, and 13 Reason J. Human Error. Cambridge,
England: Cambridge University Press; 1990.
an active diagnostic time-out, I reviewed
failure to consider the correct diagnosis
14 Pronovost P, Needham D, Berenholtz S, et al.
An intervention to decrease catheter-related
bloodstream infections in the ICU. N Engl
15 Gawande A. The checklist. The New Yorker. 16 Berenholtz SM, Pronovost PJ, Lipsett PA, et
al. Eliminating catheter-related bloodstream
infections in the intensive care unit. Crit Care
17 Haynes AB, Weiser TG, Berry WR, et al. A Acknowledgments: The authors are indebted to
surgical safety checklist to reduce morbidityand mortality in a global population. N Engl
Conclusions
Amy Miranda, Grace Garey, Mary-Lou Glazer,and Wendy Isser for their expert administrative
18 Sloman S. The empirical case for two systems
of reasoning. Psychol Bull. 1996;119:3–22. 19 Croskerry P. Clinical cognition and
process model of reasoning. Adv Health Sci
Educ Theory Pract. 2009;14(suppl 1):27–35. Ethical approval: Not applicable.
for checklists? (3) Who should review the
20 Croskerry P. Cognitive and affective
dispositions to respond. In: Croskerry P,Cosby K, Schenkel S, Wears R, eds. Patient
References
Safety in Emergency Medicine. Philadelphia,
Will checklists be valued or even accepted
1 Elstein AS. Clinical judgment: Psychological
Pa: Lippincott Williams & Wilkins; 2009:
research and medical practice. Science. 1976;
21 Graber ML. Educational strategies to reduce 2 Berner ES, Graber ML. Overconfidence as a
diagnostic error: Can you teach this stuff?
cause of diagnostic error in medicine. Am J
3 Bhasale AL, Miller GC, Reid S, Britt HC. 22 Hayward RA, Asch SM, Hogan MM, Hofer
TP, Kerr EA. Sins of omission: Getting too
little medical care may be the greatest threat
study. Med J Aust. 1998;169:73–76.
to patient safety. J Gen Intern Med. 2005;20:
4 Leape LL, Brennan TA, Laird N, et al. The 23 Croskerry P. Timely recognition and
diagnosis of illness. In: MacKinnon N, ed.
Practice Study II. N Engl J Med. 1991;324:
5 Graber ML, Franklin N, Gordon R.
Checklists are mandatory for pilots.
System. Ottawa, Ontario, Canada: Canadian
Diagnostic error in internal medicine. Arch
Pharmacists Association; 2007:79 –93. 24 Croskerry P. Context is everything or how 6 Miller RA. Computer-assisted diagnostic
could I have been that stupid? Healthc Q.
decision support: History, challenges, and
2009;12 Spec No Patient:e171–e176.
reasonable if they can be shown to work. 25 Taleb NN. The Black Swan. New York, NY:
Pilots do not have the option of skipping
26 Schiff GD, Hasan O, Kim S, et al. Diagnostic 7 Rosenbloom ST, Geissbuhler AJ, Dupont
error in medicine: Analysis of 583 physician-
(sunny day, familiar airport, experienced
reported errors. Arch Intern Med. 2009;169:
design on user-initiated access toeducational and patient information during
physicians to “use this checklist exactly
clinical care. J Am Med Inform Assoc. 2005;
27 Kachalia A, Gandhi TK, Puopolo AL, et al.
when you think you don’t need it” will
likely be met with skepticism. It would be
8 Singh H, Petersen LA, Thomas EJ.
emergency department: A study of closedmalpractice claims from 4 liability insurers.
Understanding diagnostic errors in medicine:A lesson from aviation. Qual Saf Health Care. 28 Plebani M. Exploring the iceberg of errors in 9 Mamede S, Schmidt HG, Rikers R. Diagnostic
laboratory medicine. Clin Chim Acta. 2009;
errors and reflective practice in medicine.
might identify “red flags” that should
J Eval Clin Pract. 2007;13:138 –145. 29 Elstein AS. Clinical reasoning in medicine. In:
Higgs J, Jones MA, eds. Clinical Reasoning in
prompt a time-out and checklist review. 10 Croskerry P. The importance of cognitive
errors in diagnosis and strategies to minimize
Generic red flags might include failure to
Butterworth-Heinemann; 1995:49 –59.
respond to initial treatment, second visit
30 Mitchell DJ, Russo JE, Pennington N. Back to
explanation of events. J Behav Decis Making. 11 Gawande A. The Checklist Manifesto—How 31 Kahneman D, Klein G. Conditions for
diagnostic errors. Complaint-specific red
intuitive expertise: A failure to disagree. Am
Academic Medicine, Vol. 86, No. 3 / March 2011
32 Wears RL. What makes diagnosis 47 Smith DS. Field Guide to Bedside Diagnosis. 59 McPhee SJ, Bird JA, Fordham D, Rodnick JE,
hard? Adv Health Sci Educ Theory Pract.
Philadelphia, Pa: Lippincott Williams &
activities by primary care physicians. Results
33 Kovacs G, Croskerry P. Clinical decision 48 Louis AA. Handbook of Difficult Diagnosis.
of a randomized, controlled trial. JAMA.
making: An emergency medicine perspective.
New York, NY: Churchill Livingstone; 1990. 49 Lewis C, Norman DA. Designing for error. 60 Balas EA, Weingarten S, Garb CT, 34 Campbell SG. Advances in emergency
In: Norman D, Draper S, eds. User Centered
medicine: A 10-year perspective. Can J Diag.
System Design: New Perspectives in Human-
physicians. Arch Intern Med. 2000;160:301–
35 Croskerry P. Avoiding pitfalls in the
emergency room. Can J Contin Med Educ. 50 Wilson RM, Runciman WB, Gibberd RW, 61 Marill KA, Gauharou ES, Nelson BK,
Peterson MA, Curtis RL, Gonzalez MR. 36 Vickers AJ, Basch E, Kattan MW. Against
Quality in Australian Health Care Study. Med
Prospective, randomized trial of template-
diagnosis. Ann Intern Med. 2008;149:200 –
assisted versus undirected written recording
51 Newman-Toker DE, Pronovost PJ. 37 Schiff GD. Minimizing diagnostic error: The
Diagnostic errors—The next frontier for
department. Ann Emerg Med. 1999;33:500 –
importance of follow-up and feedback. Am J
patient safety. JAMA. 2009;301:1060 –1062. 52 Trowbridge R, Weingarten S. Clinical 62 Lieberman P, Decker W, Camargo CA Jr, 38 Redelmeier DA. Improving patient care. The
decision support systems. In: Shojania K,
Oconnor R, Oppenheimer J, Simons FE.
cognitive psychology of missed diagnoses.
Duncan B, McDonald K, Wachter R, eds.
Making Health Care Safer: A Critical Analysis
39 Crandall B, Wears RL. Expanding
of Patient Safety Practices. Rockville, Md:
department. Ann Allergy Asthma Immunol.
perspectives on misdiagnosis. Am J Med.
Agency for Healthcare Research and Quality;
63 Leape LL, Berwick DM, Bates DW. What 40 Shojania KG, Burton EC, McDonald KM, 53 Payne TH. Computer decision support
practices will most improve safety? Evidence-
systems. Chest. 2000;118(2 suppl):47S–52S.
based medicine meets patient safety. JAMA. 54 Patterson ES, Doebbeling BN, Fung CH,
systematic review. JAMA. 2003;289:2849 –
Militello L, Anders S, Asch SM. Identifying
64 Gaither C. What your doctor doesn’t know
barriers to the effective use of clinical
could kill you. Boston Globe. July 14, 2002. 41 Adler SN, Adler-Klein D, Gasbarra DB. A
reminders: Bootstrapping multiple methods.
Pocket Manual of Differential Diagnosis. 5th
J Biomed Inform. 2005;38:189 –199.
ed. Philadelphia, Pa: Lippincott Williams &
55 Bates DW, Kuperman GJ, Wang S, et al. Ten
commandments for effective clinical decision
65 McDonald CJ, Wilson GA, McCabe GP Jr. 42 Greenberger NJ. Handbook of Differential
support: Making the practice of evidence-
Physician response to computer reminders.
Diagnosis in Internal Medicine: Medical Book
based medicine a reality. J Am Med Inform
of Lists. 5th ed. St. Louis, Mo: Mosby; 1998. 66 Shoemaker WC, Corley RD, Liu M, et al. 43 Wiener SL. Differential Diagnosis of Acute 56 Johnson CW. Why did that happen?
Development and testing of a decision tree
Exploring the proliferation of barely usable
for blunt trauma. Crit Care Med. 1988;16:
44 Stern S, Cifu A, Atkorn D. Symptom to
Health Care. 2006;15(suppl 1):i76 –i81. 67 Friedman CP, Gatti GG, Franz TM, et al. Do
Diagnosis: An Evidence-Based Guide. 2nd ed. 57 Graber MA, VanScoy D. How well does
correct? Implications for decision support
45 Siegenthaler W. Differential Diagnosis in
and error reduction. J Gen Intern Med. 2005;
58 Garg AX, Adhikari NK, McDonald H, et al. Reference cited only in figure
Effects of computerized clinical decision
46 Collins RD. Differential Diagnosis in Primary
support systems on practitioner performance
68 Stanovich KE. Dysrationalia: A new specific
Care. 4th ed. Philadelphia, Pa: Lippincott
and patient outcomes: A systematic review.
learning disability. J Learn Disabil. 1993;26:
Academic Medicine, Vol. 86, No. 3 / March 2011
A spirometer is a vital tool in the measurement of lung functions. It provides important information to help diagnose, manage and treat a patient with any lung disease including asthma, and COPD (chronic obstructive pulmonary disease: emphysema, and chronic bronchitis). Most children by five years of age can perform a spirometry. The cost of owning a spirometer has been decreasing and insurance co
Nutrition and the risk of stroke Lancet Neurol 2012; 11: 66–81 Poor nutrition in the fi rst year of a mother's life and undernutrition in utero, infancy, childhood, and adulthood This online publication predispose individuals to stroke in later life, but the mechanism of increased stroke risk is unclear. Overnutrition also has been corrected. increases the risk of str