Diagnosis: Reducing Errors and Improving Quality¶

Part 1: The Profession of Medicine · Part 1 – The Profession of Medicine · Chapter 10

Key Clinical Points¶

Diagnostic error is defined by the NAM as the failure to (a) establish an accurate/timely explanation or (b) communicate that explanation to the patient.
40,000–80,000 patients die annually in U.S. hospitals alone from diagnostic errors.
Errors are driven by cognitive biases (e.g., anchoring, premature closure), system failures, and limitations of human memory/time.
Diagnosis is a 'co-production' involving clinicians, the patient, and the family.
New models emphasize moving away from 'master clinician' lore toward systems-based approaches and just-in-time information.
Red flags and 'don't miss' diagnoses are critical for safety; these should be supported by context-relevant decision support.
Health IT supports diagnosis through closed loops, automated differential lists, and real-time collaboration.
Clinicians should ask 3 questions per patient: 'What else might this be?', 'What doesn't fit?', and 'What critical diagnoses are important not to miss?'
Practitioners must evaluate 3 system factors: Reliable closed loops, safety culture, and EMR efficiency.
Diagnostic pitfalls often arise from misinterpreting test results or failing to recognize atypical presentations.

1. DEFINITION & OVERVIEW¶

• Definition of Diagnosis: ◦ Diagnosis is the essence of medicine; it is both an ancient art and a modern science. ◦ It involves fields including cognitive psychology, systems engineering, reliability science, clinical epidemiology, and health IT. • Diagnostic Error (NAM Definition): ◦ The failure to (a) establish an accurate and timely explanation of the patient's health problem(s) or (b) communicate that explanation to the patient. • Visualizing Error (Figure 10-1): ◦ Illustrates that while many errors occur, not all result in harm; however, the intersection of error and lack of communication leads to significant risk. • National Academy of Medicine (NAM) Recommendations (Table 10-1): 1. Facilitate more effective teamwork among health care professionals, patients, and families. 2. Enhance professional education in clinical reasoning, teamwork, communication, and appropriate use of diagnostic tests. 3. Ensure health information technologies support the diagnostic process. 4. Develop/deploy approaches to identify, learn from, and reduce errors and near misses with systematic feedback. 5. Establish a work system and culture that supports the diagnostic process. 6. Develop a reporting environment and medical liability system that facilitates learning from errors. 7. Design a payment and care delivery environment that supports the diagnostic process. 8. Provide dedicated funding for research on the diagnostic process and errors. • Cognitive Biases (Table 10-2): 1. Premature closure: Accepting a diagnosis before it is fully verified. 2. Anchoring: Fixating on early information/symptoms without adjusting. 3. Confirmation bias: Seeking confirming evidence rather than disconfirming evidence. 4. Search satisficing: Stopping search once one piece of data or presumed explanation is found. 5. Availability bias: Over-weighting recent or dramatic cases. 6. Base-rate neglect: Failing to account for disease prevalence (e.g., misinterpreting a positive test in low-prevalence populations). 7. Knowledge deficit: Lack of awareness/knowledge on the provider's part. 8. Framing bias: Judgment influenced by how the problem is presented. 9. Social/demographic/stereotype bias: Prejudices regarding gender, race, or other identities distorting assessment.

2. EPIDEMIOLOGY¶

• Prevalence: Diagnostic errors are the leading type of medical error. • Mortality: ◦ Conservative estimates: 40,000–80,000 patients die annually in U.S. hospitals alone from diagnostic errors.

3. ETIOLOGY & PATHOPHYSIOLOGY¶

• Root Causes of Error: ◦ Hasty judgments ◦ Biased judgments ◦ Inaccurate probability estimates • Cognitive Psychology Factors: ◦ Humans use 'heuristics' (mental shortcuts) which are useful for efficiency but can lead to bias. • Contributing Factors: ◦ Limitations of human memory, information shortfalls, constrained time, system failures, and non-specific symptoms. • New Models for Conceptualizing Diagnosis (Table 10-3): 1. Certainty: Traditional: 'Get it right first time' → New: Diagnosis is an inexact science with inherent uncertainties. 2. Memory: Traditional: Reliance on master clinician memory → New: Less reliance on fallible human memory; use just-in-time info look-up. 3. Ownership: Traditional: Diagnosis is the doctor's job → New: Co-production by clinicians and patients/families. 4. Timing: Traditional: Separate stages (diagnosis then treatment) → New: Integrated strategies based on urgency. 5. Testing: Traditional: Order many tests to avoid missing things → New: Judicious, targeted ordering. 6. Safety Culture: Traditional: Fear of malpractice/defensive medicine → New: Drive out fear; make it safe to share errors. 7. Support: Traditional: Dreading complex dilemmas → New: Welcoming challenges with adequate support (time, help, consultations). 8. Documentation: Traditional: Viewed as a burden for billing/legal → New: Tool for reflection, crafting shared assessments, and highlighting questions. 9. Disclosure: Traditional: Hide errors from patients → New: Patients have right to honest disclosure; engage their concerns. 10. System Design: Traditional: More rules/targeting outliers → New: Standardization with flexibility; learning from deviations.

4. CLINICAL FEATURES¶

• Don't Miss Diagnoses (Table 10-4): 1. Infections/Inflammation: ◦ Spinal epidural abscess ◦ Meningitis ◦ Peritonsillar abscess ◦ COVID-19 infection ◦ Ebola infection 2. Cardiac/Ischemic/Bleeding: ◦ Aortic dissection ◦ Leaking/ruptured abdominal aortic aneurysm (AAA) ◦ Pericardial tamponade ◦ Wolff-Parkinson-White ◦ Prolonged QT ◦ Pulmonary embolism ◦ Acute mesenteric ischemia ◦ Sigmoid volvulus ◦ Esophageal, bowel perforation ◦ Cerebellar hemorrhage ◦ Testicular, ovarian torsion ◦ Retroperitoneal hemorrhage ◦ Ectopic pregnancy 3. Metabolic/Hematologic/Environmental: ◦ Diabetes ketoacidosis (DKA) ◦ Hyperosmolar hyperglycemia ◦ Addison's disease ◦ von Willebrand's disease ◦ Celiac sprue ◦ Food poisoning ◦ Rhabdomyolysis ◦ Alcohol, benzodiazepine, barbiturate withdrawal • Generic Types of Diagnostic Pitfalls (Table 10-5): 1. Disease A mistaken for disease B: ◦ Aortic dissection misdiagnosed as acute myocardial infarction. ◦ Bipolar disorder misdiagnosed as depression. 2. Failure to recognize atypical presentation: ◦ Apathetic hyperthyroidism. ◦ Sepsis in elderly patient who is afebrile or hypothermic. 3. Perils of intermittent symptoms/misleading evolution: ◦ "Lucid interval" in traumatic epidural hematoma. ◦ Paroxysmal arrhythmias. ◦ Intermittent hydrocephalus (Bruns' syndrome). 4. Chronic disease/comorbidity presumed to account for new symptoms: ◦ Septic joint signs misattributed to chronic rheumatoid arthritis. ◦ Mental status change due to infection or medication misattributed to underlying dementia. 5. Drug or environmental factor not considered: ◦ Ventricular arrhythmia related to QT-prolonging drug. ◦ Achilles tendon rupture related to quinolone. 6. Failure to appreciate limitations of physical exam: ◦ Overweighing absence of tenderness/swelling in DVT (especially in telemedicine). ◦ Missing pill-rolling tremor during telemedicine visit.

5. DIAGNOSTIC APPROACH¶

• Clinical Reasoning Strategy: 1. Identify 'Don't Miss' Diagnoses: Use context-relevant decision support to flag high-risk conditions. 2. Address Information Overload: Organize and minimize data using tools; move from memory-reliance to just-in-time look-ups. 3. Utilize Health Information Technology (Table 10-6): ◦ Data Collection: Access past history; electronic collection of HPI, ROS, and social determinants. ◦ Differential Generation: Automated lists based on symptoms/demographics; AI/ChatGPT as a tool for consideration. ◦ Intelligent Ordering: System suggestions for tests based on specific considerations (e.g., celiac, pheochromocytoma). ◦ Closed Loops: Hardwire tracking of abnormal labs, missed referrals, and worrisome symptoms. ◦ Collaboration: Real-time Q&A; electronic consults; virtual co-management. 4. The "3 Questions" for Patients: ◦ What else might this be? ◦ What doesn't fit? ◦ What critical diagnoses are important not to miss?

6. MANAGEMENT & TREATMENT¶

• Safety Culture and System Management: 1. Shift from Individual to System: Move from blaming individuals to analyzing system design/failures. 2. Proactive Follow-up: Ensure "closed loops" for all tests; ensure patients are contacted if results are abnormal. 3. Communication & Disclosure: ◦ Provide honest disclosure of errors or complexities to patients. ◦ Use documentation as a tool for reflection and crafting shared assessments. 4. Team Dynamics: Share uncertainties with the team to maximize engagement and utilize multi-disciplinary collaboration (lab, radiology, nursing, etc.).

7. KEY PEARLS & CLINICAL TRAPS¶

• Systemic Questions for Clinicians: 1. Are there reliable closed loops in place? 2. Is there a positive safety culture? 3. Is the EMR/IT system efficient and supportive? • Patient as Ally: Patients hold key information; their questions should be used to trigger re-evaluation of the diagnosis. • Risk Mitigation: Use "just-in-time" look-up for rare conditions or complex differentials rather than relying on memory.

Reference Tables¶

TABLE 10-1 National Academy of Medicine Recommendations for Improving Diagnosis in Health Care 1. Facilitate more…¶

Harrison's 22e, p.56

1. Facilitate more effective teamwork in the diagnostic process among health
  care professionals, patients, and their families.
  2. Enhance professional education and training in the diagnostic process in
  areas such as clinical reasoning; teamwork; communication with patients,
  families, and other health care professionals; and appropriate use of
  diagnostic tests.
  3. Ensure that health information technologies support patients and health care
  professionals in the diagnostic process.
  4. Develop and deploy approaches to identify, learn from, and reduce diagnostic
  errors and near misses in clinical practice including providing systematic
  feedback on diagnostic performance.
  5. Establish a work system and culture that supports the diagnostic process and
  improvements in diagnostic performance.
  6. Develop a reporting environment and medical liability system that facilitates
  improved diagnosis by learning from diagnostic errors and near misses.
  7. Design a payment and care delivery environment that supports the diagnostic
  process.
  8. Provide dedicated funding for research on the diagnostic process and
  diagnostic errors.

TABLE 10-2 Selected Cognitive Biases Contributing to Diagnostic Errors 1. Premature closure: accepting a diagnosis…¶

Harrison's 22e, p.57

1. Premature closure: accepting a diagnosis before it has been fully verified
  2. Anchoring: tendency to fixate on a specific symptom or piece of information
  early in the diagnostic process with subsequent failure to appropriately
  adjust
  3. Confirmation bias: tendency to look for confirming evidence to support one’s
  diagnostic hypothesis, rather than disconfirming evidence to refute it
  4. Search satisficing: tendency to call off a search, satisfied once a piece of
  data or presumed explanation is found, and not considering/searching for
  additional findings or diagnoses
  5. Availability bias: tendency to give too much weight to diagnoses that come
  more readily to mind (e.g., recent dramatic case)
  6. Base-rate neglect: failing to adequately take into account prevalence of a
  particular disease (e.g., erroneously interpreting a positive test as indicating
  disease in a low-prevalence population using a test with 5% false-positive rate)
  7. Knowledge deficit (on part of provider, with accompanying lack of
  awareness)
  8. Framing bias: judgement overly influenced by the way the problem was
  presented (how it was framed in words, settings, or situations)
  9. Social/demographic/stereotype bias: biases from personal or cultural
  beliefs about women, historically marginalized populations such as African
  Americans, people with differing sexual identities, or other patient groups for
  whom prejudices may distort diagnostic assessment

TABLE 10-3 New Models for Conceptualizing Diagnosis and Diagnosis Improvement¶

Harrison's 22e, p.58

TRADITIONAL WAYS OF THINKING ABOUT DIAGNOSIS AND DIAGNOSTIC ERROR	NEW PARADIGMS/BETTER WAYS TO THINK ABOUT DIAGNOSIS AND IMPROVING DIAGNOSIS
Diagnosis errors and challenges
Errors are infrequent; hit-and-miss ways to learn about errors	Errors are common; systematic proactive follow-up is needed to recognize potential for errors Surveilling of high-risk situations and one’s own diagnostic performance and outcomes
Dreading complex, frustrating diagnostic dilemmas	Welcoming/enjoying intellectual/professional challenges Adequate support (time, help, consultations) for more complex patients
Documentation/communication
Viewed as time-consuming, mindless, primarily to document for billing code and/or bulwark against malpractice claims	Documentation as useful tool for reflecting, crafting, sharing assessments, differential diagnosis, reflecting about unanswered questions Opportunities for decision support interacting with computer Notes open for patients to read to help understand and critique diagnosis
Don’t let patient know about errors so they don’t become angry, mistrustful, or sue	Patients have right to honest disclosure; often find out about errors anyway (e.g., cancer evolves); anticipate, engage their concerns
Global remedies
Knowing/memorizing more medical knowledge	Knowing more about the patient (including psychosocial, past history, environmental contexts)
Exhortations to have “high index of suspicion” of various diagnoses	Less reliance on memory recall of lectures/reading; more just-in-time info look-up Affordances, alerts to red flags engineered into workflow Delineation of “don’t miss” diagnoses with design of context-relevant decision support reminders
Continuing medical education (CME) courses to expand medical knowledge	Real-time, context-aware reminders of pitfalls, critical differential diagnoses, and key differentiating features. Ready access to medical references, second opinions
Fear of malpractice suits to motivate physicians to be more careful and practice defensive medicine	Drive out fear, make it safe to learn from and share errors Shared situational awareness of where pitfalls lurk
More rules, requirements; target outlier physicians for better compliance	Standardization with flexibility; learning from deviations
Reflex changes in response to errors	Avoiding “tampering,” which entails understanding/diagnosing difference between “special cause” versus “common cause” (random) variation

TABLE 10-5 Generic Types of Diagnostic Pitfalls PITFALL Disease A mistaken for disease B Diseases often…¶

Harrison's 22e, p.59

INFECTIONS/ INFLAMMATION	CARDIAC/ISCHEMIC/ BLEEDING	METABOLIC/ HEMATOLOGIC/ ENVIRONMENTAL
Spinal epidural abscess	Aortic dissection Leaking/ruptured abdominal aortic aneurysm	Diabetes ketoacidosis Hyperosmolar hyperglycemia
	Pericardial tamponade
Meningitis	Wolff-Parkinson-White Prolonged QT	Addison’s disease
	Pulmonary embolism
Peritonsillar abscess	Tension pneumothorax	von Willebrand’s disease
	Acute mesenteric ischemia Sigmoid volvulus
COVID-19 infection	Esophageal, bowel perforation	Celiac sprue
	Cerebellar hemorrhage
Ebola infection	Spinal cord compression	Food poisoning
	Testicular, ovarian torsion
Rhabdomyolysis	Ectopic pregnancy	Alcohol, benzodiazepine, barbiturate withdrawal
	Retroperitoneal hemorrhage

TABLE 10-5 Generic Types of Diagnostic Pitfalls

PITFALL	EXAMPLES
Disease A mistaken for disease B Diseases often mistaken/misdiagnosed with each other	• Aortic dissection misdiagnosed as acute myocardial infarction • Bipolar disorder misdiagnosed as depression
Failure to recognize atypical presentation, signs, and symptoms	• Apathetic hyperthyroidism • Sepsis in elderly patient who is afebrile or hypothermic
Perils of intermittent symptoms or misleading evolution Intermittent symptoms dismissed due to normal findings (exam, lab, electrocardiogram) when initially seen	• “Lucid interval” in traumatic epidural hematoma • Paroxysmal arrhythmias • Intermittent hydrocephalus (Bruns’ syndrome)
Chronic disease or comorbidity presumed to account for new symptoms Especially in medically complex patients	• Septic joint signs misattributed to chronic rheumatoid arthritis • Mental status change due to infection or medication misattributed to underlying dementia
Drug or environmental factor not considered/overlooked Underlying etiology causing/ contributing to symptoms, or disease progression not sought, uncovered	• Ventricular arrhythmia related to QT-prolonging drug • Achilles tendon rupture related to quinolone
Failure to appreciate limitations of physical exam Now with ↑ telemedicine, missing physical exam entirely	• Overweighing absence of tenderness, swelling in deep vein thrombosis • Missing pill-rolling tremor during telemedicine visit

TABLE 10-6 Areas Where Health Information Technology Has Potential to Help Improve Diagnosis and Reduce Errors FUNCTION…¶

Harrison's 22e, p.60

FUNCTION	EXAMPLES
Facilitate collection/ gathering of information	• Quickly access past history from prior care at same and outside institutions • Electronic collection of history of present illness, review of systems, and social determinant risks in advance of visits
Generating differential diagnosis	• Automated creation of lists of diagnoses to consider based on patient’s symptoms, demographics, risks • ChatGPT augmenting physician’s diagnostic considerations
Aids for formulating diagnostic plan, intelligent test ordering	• Entering a diagnostic consideration (e.g., celiac disease, pheochromocytoma) and computer suggests most appropriate diagnostic test(s) and how to order
Ensuring more reliable follow-up	• Hardwiring “closed loops” to ensure abnormal labs, missed referrals, worrisome symptoms are tracked and followed up
Collaborative diagnosis; access to specialist	• Real-time posing/answering of questions • Electronic consults; virtual co-management