Clinical Decision Making

• 2-2.30 Hot topic• 2.30-2.45 House keeping• 2.45-3.25 Presentation• 3.25-3.45 Coffee• 3.45-4.25 Case histories• 4.25-5pm Plenary

House keeping• ST1 induction next Thursday at the MAC

– others meet at BMI as usual.– cluster work on clinical areas with presentations

• Ophthalmology 1st October– questions to Malcolm please

• IMG conference 5th November – details on the website

• Residential 12th-13th November Stourport Manor Hotel– £79.00 bed & breakfast and £89.00 for double occupancy– You need to book yourselves and say it is for South B’ham VTS

• Feedback on last 2 weeks

Clinical Decision Making in General Practice

Patient’s presenting complaint

History, examination +/-

further tests

Diagnosis

Treatment

The King's Fund:The Quality of GP Diagnosis and Referral 2010

The role of the GP in diagnosis :problem recognition and decision-making.

A crucial aim of the GP in this regard is to marginalise danger by recognising and responding to signs and symptoms of possible serious illness.

The King's Fund: The Quality of GP Diagnosis and Referral 2010

The objective is not always to reach a definitive conclusion…

Quoted in "Diagnosis -The Achilles Heel?" JGR Howie JRCGP 1972

A definition of diagnosis:

A provisional formula designed

for action

The diagnostic label

• A working diagnosis on which treatment is based (such as “acute otitis media”)

• A working diagnosis on which further investigations are planned (such as “bloody diarrhoea ? inflammatory bowel disease”)

• A working diagnosis indicating the absence of serious disease (such as “calf pain, not DVT”).

Abdominal pain

Renal colic

Irritable bowel

syndrome

ConstipationChronic pelvic pain

Epigastric pain

Non specific abdominal pain

Acute cholecystitisDyspepsia

Endometriosis

Dysmenorrhoea

Two errors in diagnostic labelling

• Not making a diagnosis eg wheeze vs asthma• Prematurely making a diagnosis eg asthma vs wheeze

19/9/2003

What we say matters

• Randomised trial of positive attitude• Positive consultation with prescription

– Firm diagnosis, told it WILL get better• Positive consultation with out prescription• Negative consultation with prescription

– “I cannot be certain…” “not sure if treatment will work”• Negative consultation without prescription

– “I cannot be certain…therefore I will give no treatment”• 200 patients, URTIs, pains in arm/head/chest/back etc

19/9/2003

What we say mattersPositive

consultation(better/total)

Negative consultation(better/total)

Prescription given 32/50 21/50

No prescription 32/50 18/50

TOTAL 64/100 39/100

NNT = 4

Challenges in diagnosis in GP

• the evolutionary and undifferentiated nature of symptoms encountered in primary care

• very low prevalence of certain conditions and the high degree of overlap in symptoms for serious and common conditions

• the difficulty of probability-based reasoning and the weak predictive value of diagnostic tests in primary care

• the high prevalence of medically unexplained symptoms that lack a medically identifiable organic cause.

The King's Fund: The Quality of GP Diagnosis and Referral 2010

High quality diagnostic process

• gathering sufficient evidence and information• judging that evidence and information correctly• minimising delay in further investigation and onward

management – particularly if the condition is serious or suspected to be serious

• ensuring efficient use of resources• providing a good patient experience.

The King's Fund: The Quality of GP Diagnosis and Referral 2010

Consultation Aims: Pendleton et al

1. Define the reason for attendance.2. Consider other problems. 3. Choose an appropriate action.4. Achieve a shared understanding.5. Involve the patient in management. 6. Use time and resources appropriately. 7. Establish or maintain a relationship.

Some interesting stats re diagnosis…

• Correct diagnosis is missed or delayed in between 5% and 14% of acute hospital admissions.

• Autopsy studies confirm diagnostic error rates of 10-20% • 1/3rd adverse events involved errors of execution (slips, lapses,

or oversights in carrying out decisions)• ½ adverse effects involved errors of reasoning or decision

quality (failure to elicit, synthesise, decide, or act on clinical information)

• Reasoning errors led to death or permanent disability in at least 25% of cases, and at least three quarters were deemed highly preventable.

and management…..

• Even if the diagnosis is correct, up to 45% of patients with acute or chronic medical conditions do not receive recommended evidence based care

• Between 20% and 30% of administered investigations and drugs are potentially unnecessary

Who are these doctors?

• no more than 10% of clinicians admit, when asked, to any error in diagnosis over the past year,

• Clinicians often stay wedded to an incorrect diagnosis, even if the correct one is suggested by colleagues or by decision support tools

• Being an older and presumably more experienced clinician also does not guarantee better quality care or lower risk of reasoning error

• Most errors in clinical reasoning are not due to incompetence or inadequate knowledge but to frailty of human thinking under conditions of complexity, uncertainty, and pressure of time.

Ian Scott ; BMJ 339:22-25

• Misdiagnosis caused by hurried consideration of symptoms and failure to extract key information from patients causes a great deal more expense and patient suffering than getting things right first time.

•‘We have to be wise in the way we spend money. If physicians are paid to talk and listen to patients, and are given the training to learn how to extract the key information, it is probably going to be much more cost-effective to do that properly than rush through consultations and send patients off for a series of tests.

Edward Davie BMA

Analysis of 631 negligence claims against GPs related to diagnosis by condition

Copyright ©2009 BMJ Publishing Group Ltd.

Glasziou, P. et al. BMJ 2009;338:b1312

Stages and strategies in arriving at a diagnosis

Predicting Pulmonary Embolus in Primary Care. BMJ 8th Sept 2015

It is 4 30 pm, and your last patient of the day is a 42 year old woman in excellent health who awoke with pain located in the right infrascapular region that worsens with deep inspiration. She reports no dyspnea, cough, fever, or recent prolonged immobilization.

Her vital signs and physical examination are normal.

Your initial impression is that some type of musculoskeletal condition is causing her pain. Then you begin to wonder. Could this be a pulmonary embolus? Your gut says “no,” but your brain continues to dwell on this possibility.

Predicting Pulmonary Embolus in Primary Care. BMJ 8th Sept 2015

NICE pathway PE 2015

Heuristic techniquesmental shortcuts that ease the cognitive load of making a decision

Where no diagnostic label is applied. R Jones BMJ 25 May 2010

Sources of error in GPs’ clinical diagnostic reasoning

• Cognitive oversight— simply not thinking of the correct diagnosis,eg forgetting coeliac disease as a cause of iron deficiency anaemia

• Failure to gather adequate data— eg inadequate physical examination for lower bowel symptoms caused by colorectal cancer

• Misinterpretation of data— eg diagnosing gout on the basis of a raised serum urate concentration or excluding it on the basis of normal serum urate.

• Anchoring— sticking to an initial diagnosis despite disconfirming evidence, such as treating fatigue as depression despite evidence of abnormal renal function

• Inappropriate confirmation— selective use of evidence to confirm an incorrect diagnosis, such as attributing importance to minor abnormalities in laboratory tests as an explanation for fatigue in someone with depression

• Premature closure — arriving at a conclusive diagnosis before collecting all the data, such as diagnosing intermittent (vascular) claudication in a patient with lumbar canal spinal stenosis, jumping to conclusions

Decision-making: errors in estimate of probability

• Availability – what springs to mind might be rare but memorable or something you’ve recently experienced

• Representativeness – over estimating the likelihood of a condition because it fits a classical description of a condition ( a prototype) or the inverse.

• Probability transformations - when according to prospect theory small probabilities are overweighted and large probabilities are underweighted)

• Support theory - effect of description detail more detailed case description given higher probability)

• Order of presentation of information later presented info weighted more than earlier presented info

• Effect of benefits of detection probably linked to perceived costs of mistakes. Regret bias

• Hassle bias – making a diagnosis that will cause the least work

• Commission bias – feeling the need to do something

A man with a sore leg

Case Histories

• Introduction to case with some questions• Role play history• STOP• Examination findings if needed• Decision making• Discuss possible errors in decision making for

your case and how might you avoid them

Case 1

Chest pain

NICE. Chest pain of recent onset. last modified March 2010

NICE last modified March 2010

Chest pain of recent onset NICE

• Unless clinical suspicion is raised based on other aspects of the history and risk factors, exclude a diagnosis of stable angina if the pain is non-anginal (see recommendation 1.3.3.1).

• Other features which make a diagnosis of stable angina unlikely are when the chest pain is:– continuous or very prolonged and/or– unrelated to activity and/or– brought on by breathing in and/or– associated with symptoms such as dizziness, palpitations, tingling or

difficulty swallowing.

• Consider causes of chest pain other than angina (such as gastrointestinal or musculoskeletal pain).

Case 2

Lower abdominal symptoms

NICE……recommends that if a woman has the following symptoms and they last for a month or more, or occur on at least 12 days in a month, she should see her GP to be checked for ovarian cancer:

Feeling bloated (having a swollen tummy).Feeling full quickly and/or loss of appetite.Pain or discomfort in the lower tummy area and/or back.Needing to pass urine more often or more urgently (feeling like she can’t hold on).

NICE also says that if a woman over 50 develops symptoms similar to irritable bowel syndrome (IBS), such as bloating and changes in bowel habit, she should be offered tests by her GP to check for ovarian cancer. This is because it’s unusual for a woman of this age to develop IBS if she hasn’t had it before.

Case 3

cough

NICE Suspected cancer recognition 2015

Refer people using a suspected cancer pathway referral (for an appointment within 2 weeks) for lung cancer if they:

have chest X-ray findings that suggest lung cancer orare aged 40 and over with unexplained haemoptysis. [new 2015]

1.1.2 Offer an urgent chest X-ray (to be performed within 2 weeks) to assess for lung cancer in people aged 40 and over if they have 2 or more of the following unexplained symptoms, or if they have ever smoked and have 1 or more of the following unexplained symptoms:

CoughFatigueshortness of breath chest painweight lossappetite loss. [new 2015]

1.1.3 Consider an urgent chest X-ray (to be performed within 2 weeks) to assess for lung cancer in people aged 40 and over with any of the following:

persistent or recurrent chest infectionfinger clubbingsupraclavicular lymphadenopathy orpersistent cervical lymphadenopathy chest signs consistent with lung cancerthrombocytosis. [new 2015]

Case 4

dizziness

Hallpike test

Case 5

tiredness

The problem with GP…

• Limited time• Less acute/severe illness• Anxious patients• Reassurance role

Ways to improve decision making in diagnosis