# Diagnosis

Written by: Dr Jeremy Steinberg – created: 25 April 2022; last modified: 5 December 2022

Giovanni Battista Morgagni (1682-1771) showed that diseases could arise from specific organs and tissues with his autopsy series in "On the Seats and Causes of Disease." Artwork by Robert Thom.

Medical diagnosis is a core feature of medicine. It is a cognitive classification or "categorisation task" which allows doctors to make certain predictions about clinical situations and develop a management plan.[1]

In the fight which we have to wage incessantly against ignorance and quackery among the masses and follies of all sorts among the classes, diagnosis, not drugging, is our chief weapon of offence. Lack of systematic personal training in the methods of the recognition of disease leads to the misapplication of remedies, to long courses of treatment when treatment is useless, and so directly to that lack of confidence in our methods which is apt to place us in the eyes of the public on a level with empirics and quacks

—William Osler 1904

Annemarie Jutel, medical sociologist at Victoria Unversity writes that "With few exceptions only the medical profession has the power to diagnose disease...Being able to diagnose is at the base of the social authority afford the doctor. It sets the doctor apart from the lay person and from other professionals, confirming the doctor’s greater knowledge and status"[2]

There are some other professions in New Zealand who are afforded the status of being able to diagnose within their fields - physiotherapy, osteopathy, chiropractic, midwifery, nurse practitioners, pharmacy prescribers. There has also recently been the provision for self-diagnosis of COVID-19 through RAT testing.

## Abbreviated History

Knowing about the history of medicine can be useful for having a greater understanding about the ideological debates that continue to this day.

### Galen 129-216

Galen was a prodigy having written three books by the age of 13. He did anatomical studies on animals, and made some correct but many incorrect deductions. For example he described the rete mirabilis of the brain of a calf and assigned it to a vital physiological role in humans - but it doesn't exist in humans. He made incorrect deductions about the circulatory system, with William Harvey only correcting him over millennium later. However he made correct deductions about spinal injuries and devised that the brain not the heart was in charge of the body.

Galenism became holy writ, and later part of Church dogma. He championed blood letting (laudable pus) and used the theory of opposites called Contraria Contrariis. A famous quote from the time is "Christ as a second and neglected Galen.”

He was reported to have been incredibly arrogant. Galen believed that everything was part of a grand plan, one that only he had the power to recognise. He was very susceptible to confirmation bias and would ignore or explain away even in the absence of evidence if something did not fit within his plan. Critics of “Galen’s grand plan” and of the four humours risked severe penalties. The grand plan was one that only he could recognise, and so after his death progress in medicine essentially stopped for 1,500 years.

### Vesalius 1514-1564

Vesalius broke the dogma of Galenism. He studied anatomy through human dissections (previously disallowed). He published a highly influential work called De Humani Corporis Fabrica Libri Septum. Despite a lot of resistance from pro-Galen individuals, the human body was finally rediscovered and others followed suit.

He built the foundation of modern medicine through an anatomical view of the human body. He drew what he saw, not what Galen told him to see, but also made some errors. For example he hadn't fathomed the mechanism of circulation, he placed the lens in the centre of the eyeball, believed the vena cava came from the liver, and thought there only to be 7 cranial nerves.

Through Vesalius the anatomical view of body developed. This was the foundation of modern medicine. Others followed suit.

### Sydenham 1624-1689

Sydenham brought about the classification of disease. He was committed to naming disease to enable communication between doctors and between doctors and students. The IASP Taxonomy can be traced back to this idea.

All diseases then ought to be reduc’d to certain and determinate kinds, with the same exactness as we see it done by botanic writers in their treatises of plants

—Sydenham

### Morgagni 1682-1771

Morgagni founded the idea of patho-anatomical correlation through a publication of >500 autopsies in his book the sites and causes of disease in 1761. He compared diseased organs with normal ones and linked symptoms to abnormalities in the body. He made classic descriptions of angina, myocardial infarction, subacute bacterial endocarditis, strokes (lesion of cerebral blood vessels), hemiplegia due to a lesion on the opposite hemisphere of the brain.

Through Morgagni we got the idea that physical diseases have physical causes, often in specific organs and tissues. The humoral theory was demolished.

### Paris and German Schools of Medicine

In 19th [the] century…symptoms [became] a window into otherwise hidden disease… no longer [were they] individual phenomena, [but the] external expression of disease

—Annemarie Jutel 2011

Through the Paris school we had physical examination (including percussion and mediate auscultation), psychological assessment, and autopsies became routine for clinico-pathological correlation.

In the German school we had the likes of Virchow who propounded the cellular theory pathology and Koch with germ theory.

### Medical Humanism Model

William Osler (1849 – 1919)

The good physician treats the disease, the great physician treats the patient that has the disease

—William Osler

The medical humanism model uses the reductionist biomedical approach as a base, but it is complemented by medical humanism (see wikipedia on the philosophical movement Humanism). Humanism uses the humanities and worldly experience rather than psychological science. The model pays attention to the wishes, beliefs, fears of the patient. There are three factors, the patient, the disease, and the doctor. Humility is a vital quality in this model. He emphasised the need to stick to the clinical examination and history, with pathology and laboratory tests improving but not replacing clinical skills.

Osler was not uninterested in functional disorders (called neuroses back then), but he separated them off for supportive management and directed his focus on organic conditions.[3]

### Biopsychosocial Model

Engel developed this influential model in the 70s derived from Psychoanalysis. It avoids biological reductionism and views all spheres as equally important. It has been criticized as being anti-humanistic and using psychological ideologies masquerading as science. It implies that the psychosocial is always relevant leading to stigma even in the face of evidence that a particular problem is rooted in a biomedical cause. This is contrasted to the medical humanism model where a humanistic approach is always relevant.

The biopsychosocial model has been criticised for being non-scientific and ultimately non-humanistic. Over time the psychoanalytic emphasis has been de-emphasised and the model has come to increasingly resemble Osler's medical humanism model.[3]

### Physiological Diagnosis

In Musculoskeletal Medicine an important paradigm that developed was the idea of physiological diagnosis, for example the diagnostic local anaesthetic block. This is captured by Bogduk’s Postulates – for diagnosing pain generators. Bogduk also took us back to the ideas of Vesalius and Morgagni by going back to the dissection table in order to learn about anatomy and clinico-pathological correlation.

### Conflicts

Why diagnose cause? There were huge debates in late 18th and 19th centuries. One group said it didn’t matter, just classify and treat. Another group (the etiologists) said it did matter. The etiologists mostly won this debate but there are still some clinicians who follow the "anti-reductionism" ideology. For example the ideology of classifying almost all chronic low back pain as "non-specific chronic low back pain" (despite copious evidence that most chronic low back pain has a biomedical source) is not a new ideology by any means, and is a vestige of the debates from 200-300 years ago. The different ideologies and how they all believe themselves to be "evidence based" is discussed further in Low Back Pain Treatment Strategies.

## What is Knowledge?

This is the field of epistemology

Approximately =

• Justified – diagnosis needs to be based on something real
• True – pathophysiologically it has to be true
• Belief – I have to believe it to be true

## What is Diagnosis?

There is a difference between science and medicine. The doctor's epistemic task is to figure out how to help or cure

Diagnosis is not knowledge for knowledge’s sake. It is knowledge for the sake of action. Medicine exists to cure, to care, to intervene, or in limiting cases, to know when not to intervene. Medicine is not a contemplative science

—Mainetti 1992

It is important to remember that taxonomy is a social creation. For example dyslexia is not a disease in a non-literate society. To be a disease it needs to be visible, problematic, and perceived to be related to medicine. It is a cultural expression of what is accepted as normal (e.g. drapetomania). Consider such diagnoses as AIDS, depression, infertility, ADHD, alcohol use disorder, obesity, and fibromyalgia.

It is a classification tool by allowing segmentation and organisation. There are three types of diagnoses.

1. Patho-anatomical diagnoses (e.g. internal disc disruption)
2. Symptomatic diagnoses (e.g. migraine)
3. Medical unexplained symptoms (e.g. chronic primary pain)

## The Benefits and Harms of Diagnosis

Diagnosis is both rudder and anchor, it guides and positions.[2]

### Benefits

Diagnosis is both rudder and anchor

—Annemarie Jutel 2011

Rudder – the pursuit of a diagnosis guides the individual to the doctor

Anchor – assignment of a diagnosis positions identity and behaviour.

Personal diagnostic value to the patient

• Psychic value: patient given an explanation, clarifies, access to sick role
• Planning value: on patient life decisions e.g. work, retirement, financial plans, etc (prognosis).
• Collective identity

Intrinsic diagnostic value to the broader system

• Research and Education value: More easily group with other similar patients to study the entity and develop treatments, CPD, quality outcomes
• Tool for political engagement and advocacy.
• Resource allocation: Which specialty should assume responsibility, access to physiotherapy, medications, prostheses, disability parking, WINZ, ACC, etc.

Impact on the doctor and doctor-patient decision making

• Knowledge Access: Allows the doctor to more effectively draw from their knowledge, do a literature review, or ask colleagues.
• Positive Therapeutic Utility: some rare conditions have treatments and breakthroughs are happening all the time. And if there isn't a treatment yet the patient can be on the look out for clinical trials.
• Negative Therapeutic Utility: diagnosis can prevent misadventure through inappropriate treatment, avoiding the harms associated with diagnostic error
• Screening value: For example some genetic conditions can cause life-threatening problems unrelated to the presenting complaint. Knowing what the condition is allows the creation of a more tailored preventative health care plan.

#### The Value of the Explanation

Patients want a narrative for their pain. De-legitimisation is an experience or a series of negative consequences from not being seen to not being heard, to a sense of deficiency, and shame.

Patients have various expectations around diagnosis. Information needs are centred around a desire for a definitive diagnosis. Patients expect diagnosis through comprehensive physical examination and imaging. Accurate diagnoses are wanted for proving that their pain is real. Patients are not satisfied by “age-related wear and tear” explanations. Diagnostic satisfaction linked in with expectations of receiving a good physical examination.[4][5]

It is a psychological fact that if you tell a patient that you do not know what is the matter with them...he will immediately begin worrying. He will probably think that he has got some rare and awful disease, and will certainly think that you don’t know your job....to put into dog Latin the symptoms of which patient complains is not scientific, but it satisfies him every time . . . .

—Sykes 1927

There may be different effects on the patient whether tests confirm the patient experience or whether they do not provide an explanation.

Generally if tests confirm a patient's experience then there are positive thoughts and feelings by the patient. Patients may experience intense satisfaction with having a diagnosis.[6]

In a study of 68 individuals who had diagnostic workup for suspected multiple sclerosis, 59/62 felt better off having received diagnostic information. In those where a definitive diagnosis made patients were less anxious and expressed favourable feelings about the diagnostic workup even though they faced a lifelong chronic disease. In those where no definitive diagnosis made patients were more anxious and less reassured by the “negative” workup[7]

#### Collective Identity

There are a myriad of social media groups for patients suffering from a variety of conditions. This can be a valuable source of support if the patient is otherwise isolated.

#### Research and Education Value

There are countless examples of how the reductionist approach has lead to immeasurable improvements in human suffering. To say that there is no biomedical cause because none can be found through modern investigations is fraught because medicine is an incomplete science and we are still discovering important things all the time.

Public health is a great example. Before the 1920s in the USA 26-70% of children had goitres. Many young men were unable to enlist in the army for World War 1 due to the this. It was discovered that the soils were deficient in iodine, and iodised salt became widespread. The goitre belt vanished by World War 2.

The cause of celiac disease was discovered due to the 1944-1945 “Dutch Hunger Winter.” This famine left millions starving with a complete absence of wheat. Willen-Karel Dicke noticed that children with Celiac disease were improving and even gaining weight. When wheat flooded back these children relapsed.

Consider also schizophrenia. In the 1960s there was a psychologically oriented approach. Schizophrenia was thought to be due to to harmful emotional experiences in childhood with their primary caretakers (usually mothers). In the 1970s a biological approach emerged. It was shown that there was genetic susceptibility, biological alterations, twin studies showed family environment was irrelevant, and there were no statistically significant psychosocial traumas. The psychoanalysts were proven wrong. The reductionist approach was ultimately more humane than the psychosocial approach.

New diseases are being discovered all the time. Superior semicircular canal dehiscence was only discovered in in 1998 when CT scanning technology improved. The symptoms of this condition are pressure or sound induced vertigo, bone conduction hyperacusis, and pulsatile tinnitus. Previous to 1998 these patients were often viewed with a psychosocially oriented approach. Anti-NMDA Receptor Encephalitis was only discovered in 2007, prior to that misdiagnosis as various psychiatric diseases was common, and still happens if the diagnosis isn't considered.[8] New genetic conditions are being discovered every year. Even the most prolific diagnoser of functional disease must admit that it is highly likely that at least some patients diagnosed with functional disorders have an organic illness that has not yet been discovered or has been discovered but the diagnosis not considered.

### Harms

There are various potential harms of diagnosis

• Denial of insurance
• Denial of employment: e.g. military etc
• Negative internal appraisal: ?Lead to regard oneself as forever flawed and unable to “rise above” ones problem (hypothesis)
• External stigma: e.g. EDS, endometriosis, CFS, alcohol use disorder, depression, borderline personality disorder
• Commercial exploitation: Fertile ground for exploitation of patients and doctors (e.g. “social phobia” for shyness, endorses the use of medication)
• Marginalises unstudied populations (e.g. is endometriosis really more common in Pakeha women? Or are Pakeha women just more likely to seek care?)

## Psychiatry Explaining the Unexplainable

### History of Hysteria

The term hysteria dates back to ancient Egypt and ancient Greece. The term was "Wandering womb." It only affected women and the theory was that the uterus dries up, wanders around body and hits organs in search of water and hydration, causing pain, volatile emotions, and attention seeking. The treatment was marriage and intercourse provided moisture to stop wandering and purging of fluid retention.

The psychological explanation of symptoms became prevalent in the 18th and 19th centuries. The uterus theory was discarded and it was viewed that the problem was in the brain not the uterus. Hysteria was described as a neurological disorder in 19th century. The term hysteria became used for psychosomatic illness. Charcot espoused the neurological theory and said that physical signs and symptoms were identical in men and women but only discussed sexuality in descriptions of female hysteria. The diagnosis was increasingly applied to men. 74% (525/704) of cases were male in one large cohort study in late 19th century.

In the 20th century Freud was influential in reclassifying this into anxiety neuroses due to complex deep conflicts in the mind. The term hysteria gradually fell out of favour and was finally discarded in 1952 by the APA.

### Multiple Sclerosis

Multiple sclerosis was discovered in 1968 by Jean-Martin Charcot. It has always been a very challenging diagnosis, but was made easier by increased access to neurologists in the mid 20th century and then by MRI. Misdiagnosis as hysteria and neurosyphilis was common.

The diagnosis [of multiple sclerosis] from hysteria is of the greatest importance, and it is often very difficult and sometimes impossible.

—Charles E. Beevor (1898)

the frequent mistaking of this condition [MS] for hysteria . . . in this condition [MS] we make many mistakes. . . . [I] was often forced to revise [the] diagnosis of hysteria.The characteristic striking remissions after very grave symptoms are misleading

—Charles E. Beevor (1898)

The diagnosis of hysteria reduced in mid 20th centuries with increased correct recognition of MS, but some diagnoses were changed to “epilepsy” “psychoses” “Freudian psychoneuroses.”

The recognition of MS allowed treatments to be developed. Initially hypnotism using a psychological framework. Then in 1951 cortisone effectively treated relapses but had no long term effect. Currently more than 20 medications available for various types of MS

### New Terms for the Same Thing

We have fancy new wastebasket terms for Hysteria

Previously we used the terms wandering uterus, hysteria, sexual frustration, anxiety neuroses, Oedipus complex, and Somatisation

Now we use the terms Medically Unexplained Symptoms, central sensitisation, Somatic symptom disorder, chronic primary pain, conversion disorder, biopsychosocial, and sociopsychobiomedical.

### Prevalent Ideology in Medicine

The prevalent assumption which dates back to the 18th and 19th centuries is that if current medical expertise or medical technology can’t find the cause then it must be psychosomatic (or whatever term is in fashion). Medically unexplained is subsumed within psychiatry and used synonymously.

The symptoms are considered to be “unjustified behaviours” in a framework of thoughts, feelings, and behaviours. It is based on assumptions linked to psychosomatic disorders. A psychiatric diagnosis implies that the patient might have the ability to control and reverse the symptoms. The ideology leads to stigma and shame and encourages patient resistance.

The psychiatric explanation relies on diagnosis by exclusion. It is a wastebasket diagnosis and fails to acknowledge the limitations of knowledge. It presumes the infallibility of medicine. It shifts responsibility for cause and cure in a way that ignores sociohistorical realities.

Medically unexplained becomes one unitary label.

there is a pervasive reference to them as an entity, or as a unified condition that could be considered under one light

—Jutel
• The problem of medically unexplained symptoms
• The diagnosis of medically unexplained symptoms
• The treatment of medically unexplained symptoms

The assumption is that all complaints without explanation can be viewed in the same way.

The greater the ignorance the greater the dogmatism

—William Osler

The one unitary label under the biopsychosocial approach all too often becomes one unitary treatment. To me the ideology has a very alternative medicine flavour to it. e.g. everything is treated with manipulation in vitalistic chiropractic. It can also have a quasi-religious flavour e.g. come back when you’ve accepted the pain, if you don't accept it then you don't want to "get well" and want to "maintain the sick role." Some are so deep in this ideology that there is an outright denial of a biomedical cause even when it is staring at them in the face (consider the causes and sources of chronic low back pain).

### Patient Reactions to No Diagnosis

There is evidence to show that not providing a diagnosis leads to multiple negative thoughts and feelings. (Dumit, Nettleton, Malterud)

• Increased dissatisfaction.
• Increased distress
• Patients blame their healthcare provider for their inability to explain the cause of their pain
• Feel that their pain isn’t legitimate and disconfirmed
• Back pain is invisible, no diagnosis leads those close to them to question the legitimacy of their complaints.
• Fear of being stigmatised by a psychogenic explanation
• Feeling shame around the idea that if the pain isn't in their body then it must be in their mind.

Patient's expect the "restitution narrative." The narrative is as follows: "I have pain" -> "the doctor will examine me and do tests" -> "the source and cause of pain will be found through tests" -> "I will receive a biomechanical treatment targeted at the source and cause" -> "I will get better"

There is a gross mismatch between patients information needs and clinician knowledge. (Lim, Hoffmann).

Without a diagnosis and other forms of acceptance into the medial system, patients are denied social recognition and are even accused of faking it.[9]

## The Contested Diagnosis

Dumit wrote that there are five factors that make up a contested diagnosis.

1. Chronic
2. Uncertain aetiology and frequently biopsychosocial
3. Treatment diverse
4. Boundaries unclear
5. Many-comorbidities

"Contest" means the conflict around whether it is primarily biological, social, or psychiatric. It is accentuated by the dichotomy between illness and disease, power imbalance in the doctor-patient relationship, and a need for diagnosis before other services are able to be accessed.

Fibromyalgia

Fibromyalgia is the cardinal diagnosis that sounds biomedical but is actually vague. Patients diagnosed with fibromyalgia are initially relieved because they feel validated, feel reassurance, and feel that they have credibility. However it is not uniformly welcome. Patients often feel they need to keep it a secret. There is a sense of stigmatisation because some health care professionals are quickly disinterested.

Furthermore, most “Fibromyalgia” is not “Fibromyalgia.” Women are unequally under scrutiny for psychogenic disorders. In a 2016 study of patients diagnosed as Fibromyalgia, 73.5% did not meet the 2011 diagnostic criteria. Female = false positive OR of 8.81, Married = false positive OR of 3.27, White = false positive OR of 1.96, All three of white, married, female = true positive OR of 2.1. The authors concluded that “The diagnosis of fibromyalgia is frequently applied to those with milder somatic complaints,” “Our data suggest that the term fibromyalgia has no clear valid or reliable clinical meaning or understanding, and is socially constructed,” "“The term best reflects persons for whom fibromyalgia has become part of their health narrative”[10]

Chronic Fatigue Syndrome

The prevalent medical model for Chronic Fatigue Syndrome is that there is an initial viral illness, then symptoms perpetuated by dysfunctional illness beliefs and sickness behaviours. In a study of patients with Chronic Fatigue Syndrome, 2/3 felt they received an inappropriate psychiatric diagnosis. Patients believe strongly that their symptoms are due to a physical illness. However many doctors believe in the psychological origin. [11]

The biopsychosocial framework is not patient centred by being biased to the psychological and it is contested by patient advocacy groups. Application of biopsychosocial leads to feelings of symptoms being trivialised.[12] Furthermore the evidence for biopsychosocial model is lacking in terms of both validity and treatment approach.[13] Applying the BPS model can cause harm. [12]

Non-Specific Chronic Low Back Pain

There is no evidence that psychosocial factors are the cause of chronic low back pain . Psychosocial findings are a perfectly reasonable consequence to persistent pain. Somatisation (pre-occupation) reflects that they feel they have pain. Depression is a natural consequence of any disabling disease that mercilessly persists. Hostility is provoked by doctors telling them there is nothing wrong. Obsessive compulsive traits because of dwelling on the pain that doesn’t remit. Psychotocism because they feel isolated in their suffering. Frustration because success is persistently thwarted[14]

## Uncertainty

Main article: Uncertainty

There is a difference between non-diagnosis and uncertainty

Consider the following:

• 10 minute episode of chest pain. Full work up for cardiac factors all clear. We can apply the non-diagnosis of non-cardiac chest pain, and this is usually sufficient.
• 6 months of recurrent daily chest pain, full work up by gastroenterology, cardiology, and musculoskeletal medicine all clear. The non-diagnosis of non-cardiac chest pain may not be a sufficient explanation for the patient. There is diagnostic uncertainty - “medically unexplained.”

There are two types of uncertainty. Aleotoric is chance uncertainty. It relates to disease variability, disease incidence, and outcome variability. Epistemic uncertainty relates to limitations in knowledge, the doctors ability to access information, the doctors ability to process information, translating population findings to individuals, and the nature of complex or poorly understood evidence.

Dhaliwal outlines three questions to ask if a diagnosis can’t be made

1. Have I reached the limit of my knowledge but not that of my colleagues?
2. Have I reached the limits of my local network’s knowledge but not that of another physician or team elsewhere?
3. Have I reached the limits of medical knowledge entirely (i.e., there is no known answer to the problem)?

Open questions include at what point do you “stop” and call a problem idiopathic? At what point do you call it a conversion disorder, functional, “psychosocial” or as some call it “sociopsychobiomedical.” At what point do we say “we don’t know” and “that part of the manual of the human body hasn’t been written yet.” In Musculoskeletal Medicine ACC may make the decision on the doctor and patient's behalf of when to stop.

## Diagnostic Clinical Reasoning

The hypothetico-deductive model is the classic model of medical diagnosis. It is an iterative process of hypothesis generation and testing. The doctor generates hypothesis that they try to confirm or refute through patient cues and collection of data. The model has been repeatedly validated.[1]

Dual Process Theory is a key theory in the study of clinical reasoning. There are two cognitive systems at play, but they are not exclusive in the real world. The doctor oscillates between the two, even within the same case.

System 1

• Reflexive, intuitive
• Efficient
• Pattern recognition
• E.g. 45 year old woman with a BMI of 40 with medial knee pain = knee OA
• Can lead to anchoring bias

System 2

• Analytical, cognitive
• Time intensive, deliberate
• Conscious, explicit application of analytical approach
• E.g. assessing the location of the lesion in foot drop.
• Can lead to putting undue emphasis on a clinical feature

Slow Thinking Example Framework

1. Collect Data and distil into pertinent positives and negatives
2. Create a Problem Representation
3. Search for and selection of Illness Scripts through a Diagnostic Schema
4. Diagnosis;

## Diagnostic Error

The "big three" for diagnostic error are cancer, infection, and vascular Events. These account for three quarters of of serious misdiagnosis related harms. Rates of diagnostic error for these range from 2.2% (myocardial infarction) to 62% (spinal abscess), median of 13.6%. Misdiagnosis harms range from 1.2% (MI) to 35.6% (spinal abscess), median of 5.2%.[15][16][17]

Most people will experience a diagnostic error in their lifetime. Most diagnostic errors occur through flaws in clinical reasoning skills. This is through deficiencies in data collection, data integration, data verification, leading to premature diagnostic closure.

Common cognitive biases include[18]

• Overestimation - similar to expectations of high stock returns among investors.
• Base rate neglect - true base rates are usually lower than expected
• Anchoring bias - reflects experiences that represent improbable events.
• Confirmation bias - looking for evidence to fit original hypothesis while ignoring evidence that refutes it.

78% would treat cardiac ischaemia when a positive test result places their patient at 11% of less chance of disease.[19]

## Competencies in Diagnosis

Olson et al published an important paper on the foundational concepts and core competencies of modern diagnosis. [20]

### Foundational Concepts

1. .The primacy of medical knowledge
2. The dual-processing paradigm as a framework for understanding clinical reasoning
3. The value of rational thought and reflection
4. The value of experience and of feedback: learning from outcomes of decisions
5. The dynamic nature of diagnosis – the inevitable problems of uncertainty and complexity
6. The inherent power of teamwork, of patient engagement, and of health information technology
7. The relevancy of human factors and “the system” in determining diagnostic performance
8. The limits and biases of human cognition
9. The value of recognising high risk and “red flag” situations
10. The need to prioritise and triage appropriately
11. The need to focus on the needs of the patient
12. Assessment of diagnosis should include measures of skillful differential diagnosis and diagnostic efficiency

Desirable Attributes are Courage, Humility, Empathy, Flexibility, Integrity, Intellectual autonomy, Kindness, Persistence, Professionalism, Resilience and adaptability, Tolerance of uncertainty, Skepticism, Curiosity, Respect, Patience

### Individual Competencies

1. Collect key clinical findings to inform hypotheses
2. Formulate problem representation
3. Correctly prioritise red flag diagnoses
4. Create and prioritise a differential diagnosis
5. Use support tools including checklists and second opinions
6. Use strategies to mitigate cognitive bias.

### Team-based Competencies

1. Engage with patient and family values and preferences, share uncertainty
2. Collaborate with other health care professionals
3. Safely transfer care, close loop on test result communication.

### System-related Competencies

1. Mitigate system factors that detract from diagnostic quality and safety
2. Advance a culture of diagnostic safety with continuous learning about diagnostic performance
3. Disclose diagnostic errors and missed opportunities to patients and team members

## Checklists

More than 40 biases but most lead to a single pathway where the doctor fails to generate an adequate differential diagnosis or even consider the correct one as a possibility.

Most common reason for diagnostic error is “I just didn’t think of it.” Using diagnostic checklists may improve diagnostic performance in difficult cases.

### General Checklist

• Did I just accept the first diagnosis to mind?
• Did the patient come with a previous diagnosis?
• Should I review patient records before they leave?
• Is there anything that doesn’t fit with the diagnosis?
• Did I do the history, exam, and review the imaging myself?
• Where they seen recently for the same problem? What was done and what has changed?
• Any external pressures?

### Clinically Oriented Checklist

This type of list has specific conditions to consider for different presenting complaints. The checklist may highlight "do not miss" and "commonly missed" conditions. See Portal:Differential diagnoses. For example, a checklist for neuropathic arm pain:

Differential Diagnoses for Neuropathic Arm Pain

• Annemarie Goldstein. Putting a Name to It: Diagnosis in Contemporary Society. Johns Hopkins University Press. 2011
• S Nassir Ghaemi. The Rise and Fall of the Biopsychosocial Model: Reconciling Art and Science in Psychiatry. JHUP. 2012.

## References

1. Charlin, B.; Tardif, J.; Boshuizen, H. P. (2000-02). "Scripts and medical diagnostic knowledge: theory and applications for clinical reasoning instruction and research". Academic Medicine: Journal of the Association of American Medical Colleges. 75 (2): 182–190. doi:10.1097/00001888-200002000-00020. ISSN 1040-2446. PMID 10693854. Check date values in: |date= (help)
2. Annemarie Goldstein Jutel. Putting a Name to It: Diagnosis in Contemporary Society. Johns Hopkins University Press. 2011
3. S Nassir Ghaemi. The Rise and Fall of the Biopsychosocial Model: Reconciling Art and Science in Psychiatry. JHUP. 2012.
4. Lim, Yuan Z.; Chou, Louisa; Au, Rebecca Tm; Seneviwickrama, Kl Maheeka D.; Cicuttini, Flavia M.; Briggs, Andrew M.; Sullivan, Kaye; Urquhart, Donna M.; Wluka, Anita E. (2019-07). "People with low back pain want clear, consistent and personalised information on prognosis, treatment options and self-management strategies: a systematic review". Journal of Physiotherapy. 65 (3): 124–135. doi:10.1016/j.jphys.2019.05.010. ISSN 1836-9561. PMID 31227280. Check date values in: |date= (help)
5. Verbeek, Jos; Sengers, Marie-José; Riemens, Linda; Haafkens, Joke (2004-10-15). "Patient expectations of treatment for back pain: a systematic review of qualitative and quantitative studies". Spine. 29 (20): 2309–2318. doi:10.1097/01.brs.0000142007.38256.7f. ISSN 1528-1159. PMID 15480147.
6. Rhodes, L. A.; McPhillips-Tangum, C. A.; Markham, C.; Klenk, R. (1999-05). "The power of the visible: the meaning of diagnostic tests in chronic back pain". Social Science & Medicine (1982). 48 (9): 1189–1203. doi:10.1016/s0277-9536(98)00418-3. ISSN 0277-9536. PMID 10220019. Check date values in: |date= (help)
7. Mushlin, A. I.; Mooney, C.; Grow, V.; Phelps, C. E. (1994-01). "The value of diagnostic information to patients with suspected multiple sclerosis. Rochester-Toronto MRI Study Group". Archives of Neurology. 51 (1): 67–72. doi:10.1001/archneur.1994.00540130093017. ISSN 0003-9942. PMID 8274112. Check date values in: |date= (help)
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