2 - Clinical Decision Making (13.01.2020)

Question 1

Medical Error

Answer 1

An error is defined as the failure of a planned action to be completed as intended (i.e., error of execution) or the use of a wrong plan to achieve an aim (i.e., error of planning).

Examples:

• incorrect diagnosis
• failure to employ indicated tests
• error in the performance of an operation, procedure, or test,
• error in the dose or method of using a drug.

Question 2

What are the most common medical errors?

Answer 2

Diagnostic errors

Question 3

What are the main causes of diagnostic errors?

Answer 3

46% system related and cognitive factors

Question 4

How does clinical decision making work?

Answer 4

• Clinicians rarely use formal computations to make patient care decisions in day-to-day practice.
• Intuitive understanding of probabilities is combined with cognitive processes called heuristics to guide clinical judgment.
• Heuristics are often referred to as rules of thumb, educated guesses, or mental shortcuts.
• Heuristicsusually involve pattern recognitionand rely on a subconscious integration of patient data with prior experience

Question 5

What are the 2 systems of decision making?

Answer 5

• Hot system -> 1 -> fast
• Cold system -> 2-> slow, putting thought

=> we use both in different situations

• we can override system 1 by using system 2 (e.g. the experiment with 2 lines, arrows inwards and outwards - which one is longer?)
• sometimes we think we are using 2 but we are using 1
• > System 1 (Hot) often controls our actions automatically but system 2 (Cold) is blissfully unaware, believing itself to be in charge!

Question 6

Confirmatory Bias

Answer 6

• The tendency to search for or seek, interpret, and recall information in a way that confirms one’s preexisting beliefs or hypotheses, often leading to errors
• Is confirmation bias to blame for the ineffective medical procedures that were used for centuries before the arrival of scientific medicine?
• When evaluating a diagnosis be sure to test for alternatives

=> Seeking information that confirms our thoughts rather than information than new information to challenge our thoughts and make up our opinion.

Question 7

Sunk cost fallacy

Answer 7

• cognitive error that can creep in
• making decisions, thinking that the future outcome depends on what we have done so far.
• I have waited for 1 minute, it would be silly to leave now. (waiting for life) but actually this is irrelevant for the outcome OR we have treated the patient for this for so long, we cannot give up now.
• any actions should be based on risk and benefits of that action in the future and not on what actions were already invested

Question 8

Anchoring

Answer 8

• e.g. when stores advertise with was £80 and is now £40 or in bargaining, you start with a higher starting point
• Individuals poor at adjusting estimates from a given starting point (probs. & values)
• Adjustments crude & imprecise
• Anchored by starting point

Question 9

Anchoring effect

Answer 9

• A working diagnosis of acute pancreatitis may seem quite reasonable in a 60-yr-old man who has epigastric pain and nausea, who is sitting forward clutching his abdomen
• However, the patient states that he has had no alcohol in many years and investigations show normal blood levels of pancreatic enzymes
• Clinicians may simply dismiss or excuse conflicting data (eg, the patient is lying, his pancreas is burned out, the laboratory made a mistake)

Question 10

Probabilities

Answer 10

• used in medical decision making
• Many clinical situations involve making decisions on the basis of probabilities e.g. two or more competing diagnoses, alternative treatments which may be effective etc.
• What is the probability it is this diagnosis rather than the other one?
• What are the chances that this will be mor eeffectove then something else?

Question 11

Representativeness heuristic

Answer 11

• Subjective probability that a stimulus belongs to a particular class based on how ‘typical’ of that class it appears to be (regardless of base rate probability)
• While often very useful in everyday life, it can also result in neglect of relevant base rates and other errors.

Representativeness errors:

• A 60-yr-old woman who has no known medical problems and who now looks and feels well reports experiencing symptoms earlier of feeling short of breath, sweaty and clammy, feeling sick, and feeling faint.
• ThisdoesnotmatchthetypicalprofileofanMI, which is typically characterised by chest pain.
• BUT, it would be unwise to dismiss that possibility because MI is common among women of that age
and has highly variable presentations.

Question 12

Framing and age

Answer 12

When presented with treatment descriptions described in positive, negative, or neutral terms, older adults are significantly more likely to agree to a treatment when it is positively described than they are to agree to the same treatment when it is described neutrally or negatively

Question 13

The Availability Heuristic

Answer 13

• Probabilities are estimated on the basis of how easily and/or vividly they can be called to mind.
• Individuals typically overestimate the frequency of occurrence of catastrophic, dramatic events e.g. surveys show 80% believe that accidents cause more deaths than strokes
• People tend to heavily weigh their judgments toward more recent information

Question 14

What can be done about cognitive errors and heuristics? How can decision making be improved?

Answer 14

1) Education and Training
Integrate teaching about cognitive error and diagnostic error into medical school curricula
Recognise that heuristics and biases may be affecting our judgement even though we may not be conscious of them

2) Feedback
Increase number of autopsies Conduct regular and systematic audits Follow-up patients

3) Accountability
Establish clear accountability and follow-up for decisions made

4) Generating alternatives
Establish forced consideration of alternative possibilities e.g., the generation and working through of a differential diagnosis. Encourage routinely asking the question: What else might this be?

5) Consultation
Seek second opinions
Use of algorithms
Use of clinical decision making support systems

Also coming up with differential diagnoses to encourage more critical thinking about what it could be, seek second opinions. Or you can also use algorithm,s because probability calculation in medicine can be difficult (on the spot).

Question 15

Algorithms

Answer 15

• An algorithm is a procedure which, if followed exactly, will provide the most likely answer based on the evidence.
• The rules of probability are examples of algorithms.
• Algorithms are most useful in situations where the problem is well defined - which excludes many everyday decisions
• For the most part, people have to be taught how to use them