Diagnosis: Reducing Errors and Improving Quality

57CHAPTER 9

TABLE 9-3 New Models for Conceptualizing Diagnosis and Diagnosis Improvement

TRADITIONAL WAYS OF THINKING ABOUT DIAGNOSIS

AND DIAGNOSTIC ERROR NEW PARADIGMS/BETTER WAYS TO THINK ABOUT DIAGNOSIS AND IMPROVING DIAGNOSIS

Redundancies, double-checks Recognition that single, highly reliable systems are often better than multiple halfway solutions.

Clear delineation of responsibilities for follow-up tasks

Fear of malpractice suits to motivate physicians to be more

careful and practice defensive medicine

Drive out fear, making it safe to learn from and share errors

Shared situational awareness of where pitfalls lurk

More accountability, financial incentives, and penalties tied

to performance metrics

Clinician engagement in improvement based on trust, collaboration, professionalism, financial neutrality

Metric modesty, recognizing many best practices yet to be defined/proven

More rules, requirements; target outliers for better

compliance

Standardization with flexibility; learning from deviations

More time with patients Better time spent with patients: offloading distractions, more efficient history collection/organization,

longitudinal continuity, and, where needed, additional time to talk/think/explain during, before, or after

visits

Easier access for patients to reach or be seen by clinicians when experiencing symptoms

Reflex changes in response to errors Avoiding “tampering,” which entails understanding/diagnosing difference between “special cause”

versus “common cause” (random) variation

Source: Modified from GD Schiff: Quality and Safety in Health Care 2013.

can go wrong and create safety nets to protect patients against harms

from delayed diagnosis and misdiagnosis. Terms such as preliminary

diagnosis, working diagnosis, differential diagnosis, deferred diagnosis,

undiagnosed illness, diagnoses with uncertain or multifactorial etiologies, intermittent diagnoses, multiple/dual diagnoses, self-diagnosis, or at

times contested diagnosis need to be part of our vocabulary, thinking,

and communications with patients to convey that diagnosis is often

imprecise. Anxious patients worried about a condition, for example,

cancer, COVID-19 infection, or a diagnosis to which a relative or a

friend has recently succumbed, come seeking reassurance and may not

welcome an uncertain answer. Thus, we have to work with patients,

listen to and respect their concerns, and take their symptoms seriously

yet modestly acknowledge our limitations. We need to tailor this

approach to patients’ differing levels of health literacy, trust in our

clinical advice, and experiences with the health system.

■ DON’T MISS DIAGNOSES AND RED FLAGS

Uncertainty should not be a license for complacency. Particularly for

diseases that (1) progress rapidly, (2) require specific treatments that

depend on making the correct diagnosis, or (3) have public health

or contagion implications, clinicians need to be poised, and systems

designed, to consider and, where appropriate, pursue critical “don’t

miss” diagnoses. While clinicians are generally aware of more common “don’t miss” diagnoses (e.g., acute myocardial infarction, sepsis),

Table 9-4 illustrates examples of less common diagnoses that warrant

similar consideration. Throughout this textbook, readers should orient

themselves to recognize such critical diagnoses and think about presentations and syndromes where they may be lurking.

An important related concept is so-called “red flags” or “alarm

symptoms.” This construct has its origins in guidelines for back pain

but has increasingly been applied to many other problems, such as

headache, red eye, swollen joint, or even abdominal pain and chest

pain. Examples of widely cited red flags for back pain that should

trigger consideration of more serious etiologies include fever, weight

loss, history of malignancy or intravenous drug use, or neurologic

signs and symptoms. In theory, many presenting syndromes could

benefit from identification of such clues to more serious diagnoses.

Evidence-based medicine calls for better data on the sensitivity, specificity, yield, and discriminatory ability of various clinical “red flag”

clues; yet, few have been rigorously evaluated. Nonetheless, clinicians

find them useful as simple ways to reassure themselves and their

patients that a common symptom such as back pain or headache is, or

is not, likely an indicator of more urgent or serious pathology.

Interwoven with the challenges of not missing critical diagnoses is

the problem of overtesting and overdiagnosis—performing unnecessary and even potentially harmful tests whose benefit does not justify

the risks or costs or that may lead to diagnoses that would have never

caused any symptoms or problems. Thoughtful diagnosticians need to

weigh carefully this “other side of the coin” of missed diagnosis to avoid

such harms and expenses.

■ DIAGNOSTIC PITFALLS

One of the important ways of learning in medicine is learning from the

missteps of those who have walked the path ahead of us. By learning

about commonly missed diagnoses and the ways accurate, timely diagnosis went astray, we can avoid making similar mistakes. Anticipating

the potential for similar types of errors can both create situational

awareness of traps to avoid and contribute to learning from our own

personal and collective patterns of mistakes. Several studies have

examined common or recurring pitfalls in diagnosis. An example of a

common disease-specific diagnostic pitfall in breast cancer diagnosis is

ordering a mammogram for a woman with a palpable breast lump and,

when the mammogram returns as normal, reassuring her that cancer

has been “ruled out” by the negative test. Any mass or lesion palpable

(Continued)

TABLE 9-4 Examples of “Don’t Miss” Diagnoses

INFECTIONS/

INFLAMMATION

CARDIAC/ISCHEMIC/

BLEEDING

METABOLIC/

HEMATOLOGIC/

ENVIRONMENTAL

Spinal epidural abscess Aortic dissection

Leaking/ruptured

abdominal aortic

aneurysm

Diabetes ketoacidosis

Hyperosmolar

hyperglycemia

Necrotizing fasciitis Pericardial tamponade Myxedema/

thyrotoxicosis

Meningitis Wolff-Parkinson-White

Prolonged QT

Addison’s disease

Endocarditis Pulmonary embolism B12 deficiency anemia

Peritonsillar abscess Tension pneumothorax von Willebrand’s disease

Tuberculosis-active

pulmonary, other

Acute mesenteric

ischemia

Sigmoid volvulus

Hemochromatosis

COVID-19 infection Esophageal, bowel

perforation

Celiac sprue

Guillain-Barré syndrome Cerebellar hemorrhage Carbon monoxide

poisoning

Ebola infection Spinal cord compression Food poisoning

Temporal arteritis Testicular, ovarian torsion Malignant hyperthermia

Rhabdomyolysis Ectopic pregnancy Alcohol, benzodiazepine,

barbiturate withdrawal

Angioedema Retroperitoneal

hemorrhage

Tumor lysis syndrome

Hypo-/hypercalcemia

58PART 1 The Profession of Medicine

on physical examination probably needs more careful assessment proceeding all the way to invasive biopsy, if necessary. Diagnostic pitfalls

can be classified into a number of generic scenarios (Table 9-5). We

now have large databases that have the potential to track “diagnoses

outcomes”—i.e., whether a new diagnosis emerges that suggests an

initial diagnosis was incorrect or a diagnosis of a patient’s symptoms

was suboptimally delayed. This should, in the future, allow us to more

rigorously focus on these cases, to identify contributing factors and

recurring patterns, and to help point the way for systemwide improvement strategies.

■ DIAGNOSIS SAFETY CULTURE

Just as diagnosing bacterial infections relies on a proper culture

medium to grow and identify etiologic organisms, good diagnosis also

requires a healthy safety culture that will allow it to grow and flourish.

While clinicians may be inclined to view “safety culture” as something

too subjective to be important in their quest to make a definitive

diagnosis, this view is misguided. Multiple studies have demonstrated

adverse consequences resulting from organizational cultures that

inhibit openness, learning, and sharing and create a climate where staff

and patients are afraid to speak up when they observe problems or have

questions. Most importantly, patients need to be encouraged to question diagnoses and be heard, particularly when they are not responding

to treatment as expected or developing symptoms that are either not

consistent with the diagnosis or represent possible red flags for other

diagnoses or complications.

Studies examining “high-reliability organizations” outside of medicine and “learning health care organizations” have distilled a series

of fundamental properties that are correlated with more reliable

and safer outcomes. Just as a thermometer or recording of a pulse

can suggest how ill a patient is, we now have instruments that can

measure safety culture. These safety measurement tools typically are

validated staff surveys that assess (1) communication about errors

with staff willingness to report mistakes because they do not feel these

mistakes are held against them; (2) openness and encouragement to

talk about hospital/office problems; (3) existence of a learning culture

that seeks to learn from errors and improve based on lessons learned;

(4) leadership commitment to safety, prioritizing safety over production speed and the “bottom line” by providing adequate staffing and

resources to operate safely; and (5) accountability and transparency for

following up safety events and concerns. Each of these generic culture

attributes translates into specific implications for diagnostic safety.

These include the following:

• Making it “safe” for clinicians to admit and share diagnostic errors

• Proactive identification, ownership, and accountability regarding

error-prone diagnostic workflow processes (particularly around test

results, referrals, and patient follow-up)

• Leadership making diagnosis improvement a top priority based on

recognition that patients and malpractice insurers report that diagnostic errors are the leading patient safety problem

• Mutual trust and respect for challenges that clinicians often face in

making diagnoses and caution in applying the lens of hindsight bias

in judging what in retrospect might seem like an “obvious” diagnosis

that a clinician initially missed

■ HEALTH INFORMATION TECHNOLOGY AND THE

FUTURE OF DIAGNOSIS

Clinicians now spend more time interacting with computers than they

do interacting with patients. This is especially true for diagnosis and

will likely be even more so in the future. Interactions with patients,

consultants, and other staff are increasingly mediated through the

computer. Key activities, such as collecting patients’ history (past and

current), interpreting data to make a diagnosis, conveying diagnostic

assessments (to others on the team and, increasingly, to the patient via

open notes), and tracking diagnostic trajectories as they evolve over

time, are now computer based. With the rise of telemedicine, even

elements of the physical examination have been rerouted to electronic

encounters.

While many complain the computer has “gotten in the way” of good

diagnosis, distracting clinicians from quality time listening to patients

and miring doctors in reading and writing notes filled with copied/

pasted/templated information of questionable currency and accuracy,

medicine needs to harness the computer’s capabilities to improve diagnosis (Table 9-6). Although these basic diagnosis-supporting capabilities should be the foundation of the design of health information

technology and everyday workflow, electronic medical records have

historically been largely designed around other needs, such as ordering

medications and billing and malpractice documentation. They need to

be radically redesigned to better support diagnostic processes, as well

as save, rather than squander, clinicians’ time.

■ DIAGNOSIS OF DIAGNOSIS ERRORS AND SAFETY:

PRACTICAL CONCLUSIONS

In practice, there are frequent and meaningful opportunities for

improving diagnosis in each of the three NAM-defined areas to make

it a) more reliable, b) timely, and c) to improve diagnosis-related

communication with patients. Clinicians in training, practicing physicians, nurses, and others should develop the habit of regularly asking

TABLE 9-5 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

Misinterpretation of test result(s)

False-positive or false-negative results

with failure to recognize test limitations

• Breast lump dismissed after

negative mammogram

• Negative COVID-19 test early or late

in course

Failure to recognize atypical

presentation, signs, and symptoms

• Apathetic hyperthyroidism

• Sepsis in elderly patient who is

afebrile or hypothermic

Failure to assess appropriately the

urgency of diagnosis

Urgency of the clinical situation was

not appreciated and/or delays critical

diagnoses

• Compartment syndrome

• Pericardial tamponade

• Tension pneumothorax

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)

Confusion arising from response/

masking by empiric treatment

• Empiric treatment with steroids,

proton pump inhibitors, antibiotics,

pain medication erroneously

masking serious diagnosis

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

Rare diagnosis: failure to consider or

know

• Many; fortunately, by definition,

rare, but still warrant consideration

especially if urgent or treatable

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 drugs

Failure to appreciate risk factors for

particular disease

• Family history of breast, colorectal

cancer not solicited and/or weighed

in diagnostic evaluation or screening

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

Racial and Ethnic Disparities in Health Care

59CHAPTER 10

TABLE 9-6 Areas Where Health Information Technology Has Potential

to Help Improve Diagnosis and Reduce Errors

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

Enhanced information

entry, organization, and

display

• Visually enhanced flowsheets showing trends,

relationships to treatment

• Reorganized notes to facilitate summarization

and simplification and prevent items from

getting lost

Generating differential

diagnosis

• Automated creation of lists of diagnoses

to consider based on patient’s symptoms,

demographics, risks

Weighing diagnoses

likelihoods

• Tools to assist in calculation of posttest

(Bayesian) probabilities

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

Access to diagnostic

reference information

• Info-buttons instantly linking symptom or

diagnosis relevant questions to Harrison’s,

Up-to-Date chapters, references

Ensuring more reliable

follow-up

• Hardwiring “closed loops” to ensure abnormal

labs, missed referrals, worrisome symptoms are

tracked and followed up

Support screening for early

detection

• Collaborative tools that patients, clinicians,

and offices can use to know when due, order

and track screening based on individualized

demographics, risk factors, prior tests

Collaborative diagnosis;

access to specialist

• Real-time posing/answering of questions

• Electronic consults; virtual co-management

Facilitating feedback on

diagnoses

• Feeding back new diagnoses (from downstream

providers, patients) that emerge suggesting

potential misdiagnosis/errors to clinicians, ERs

who saw patient previously

Abbreviation: ERs, emergency rooms.

Source: Modified from G Schiff, DW Bates: N Engl J Med 362:1066, 2010, and

R El-Karah et al: BMJ Qual Saf Suppl 2:ii40, 2013.

including the American Board of Internal Medicine (ABIM), the

American College of Physicians (ACP), and the Society of Hospital

Medicine (SHM), committed to increasing awareness and action. Ultimately, collectively tackling the challenges of improving the quality of

diagnosis will transform the way clinicians and patients work together

to co-produce better diagnoses.

■ FURTHER READING

Gandhi TK, Singh H: Reducing the risk of diagnostic error in the

COVID-19 era. J Hosp Med 15:363, 2020.

Graber ML et al: The impact of electronic health records on diagnosis.

Diagnosis (Berl) 4:211, 2017.

National Academiesof Sciences, Engineering, and Medicine. 2015.

Improving Diagnosis in Health Care. https://doi.org/10.17226/21794.

Adapted and reproduced with permission from the National Academy

of Sciences, Courtesy of the National Academies Press, Washington, DC.

Newman-Toker DE et al: Serious misdiagnosis-related harms in

malpractice claims: The “big three”—Vascular events, infections, and

cancers. Diagnosis (Berl) 6:227, 2019.

Schiff GD et al: Diagnosing diagnosis errors: Lessons from a

multi-institutional collaborative project, in Advances in Patient Safety:

From Research to Implementation. Vol 2: Concepts and Methodology.

Rockville, MD, Agency for Healthcare Research and Quality, 2005.

Schiff GD et al: Ten principles for more conservative, care-full diagnosis. Ann Intern Med 169:643, 2018.

themselves three questions about individual patients in their care, and

another three questions regarding the systems in which they work. For

each patient being assessed, clinicians should ask:

1. What else might this be? (forcing a differential diagnosis to be made)

2. What doesn’t fit? (making sure unexplained abnormal findings are

not dismissed)

3. What critical diagnoses are important not to miss? (injecting consideration of “don’t miss” diagnoses, red flags, and known pitfalls)

and to diagnose safely, each practitioner must recognize that he or she

is working within a larger system. Questions to be asking continually,

ensuring we are maximizing reliability and timeliness and minimizing

potential for errors, include:

1. Do we have reliable “closed loop” systems to provide reliable, ideally

automated tracking and following up of patients’ symptoms, abnormal

laboratory or imaging findings, and critical referrals that we order?

2. What is the culture-of-safety climate in our organization, office, or

clinic?

3. How does the electronic (or even paper) medical record as currently

implemented help versus impair efficient, timely, accurate, and failsafe diagnosis, and how can it be improved?

To take these questions to the next stage, an international movement dedicated to studying and improving diagnosis has emerged.

These efforts include annual conferences of clinicians, researchers,

and patients; the formation of the Society for Improving Diagnosis in

Medicine (SIDM); and convening of a broad coalition of organizations,

Over the course of its history, the United States has experienced

dramatic improvements in overall health and life expectancy, largely

as a result of initiatives in public health, health promotion, disease

prevention, and chronic care management. Our ability to prevent,

detect, and treat diseases in their early stages has allowed us to target

and reduce rates of morbidity and mortality. Despite interventions that

have improved the overall health of the majority of Americans, racial

and ethnic minorities (blacks, Hispanics/Latinos, Native Americans/

Alaskan Natives, Asian/Pacific Islanders) have benefited less from

these advances than whites and have suffered poorer health outcomes

from many major diseases, including cardiovascular disease, cancer,

and diabetes. These disparities highlight the importance of recognizing and addressing the multiple factors that impact health outcomes,

including structural racism, social determinants of health (SDOH),

access to care, and health care quality. On this last point, research has

revealed that minorities may receive less care and lower-quality care

than whites, even when confounders such as stage of presentation,

comorbidities, and health insurance are controlled. These differences

in quality are called racial and ethnic disparities in health care. These

health care disparities have taken on greater importance with the significant transformation of the U.S. health care system and value-based

purchasing. The shift toward creating financial incentives and disincentives to achieve quality goals makes focusing on those who receive

lower-quality care more important than ever before. This chapter will

provide an overview of racial and ethnic disparities in health and

health care, identify root causes, and provide key recommendations to

address these disparities at both the clinical and health system levels.

■ NATURE AND EXTENT OF DISPARITIES

Life expectancy at birth is an important measure of the health of

a nation’s population. Although the overall life expectancy in the

United States has been increasing since 1900, differences due to

10 Racial and Ethnic

Disparities in Health Care

Lenny López, Joseph R. Betancourt