Clinical Decision Making

Question 1

Describe Kahneman’s two systems for decision making

Answer 1

Two systems of decision making:
○ System 1 ““Hot”” system = acting quickly (emotional; ““Go””; Reflective; Simple; Fast; Develops early; Accentuated by stress; Stimulus control)
○ System 2 ““cold system”” = acting thoughtfully (Cognitive; ““Know”” Reflective; Complex; Slow; Attenuated by stress; Self control)

Question 2

How are both systems useful in particular scenarios?

Answer 2

Both system useful in certain scenarios: When you’re crossing a road and a bus is approaching you’re not gonna ‘reflect’ on the impact the bus is gonna have on your body or something you will use system 1. However, system 1 can let us down if we are in situations where we need more complex and cognitive functions.
Both systems are useful; It depends what our aims are: on how precise we wanna be or how significant we need an action to be
In clinical setting it is good to be aware which system we’re using

Question 3

What is Confirmatory Bias?

Answer 3

The tendency to search for or interpret information in a way that confirms one’s preconceptions, often leading to errors

Question 4

What is the Sunk Cost Fallacy?

Answer 4

Rationally, the only factor affecting future action should be future cost/benefit ratio BUT humans do not always act rationally
Often, the more we have invested in the past, the more we are prepared to invest in a problem in the future

Question 5

What is the Anchoring Effect?

Answer 5

People start with an implicitly suggested reference point (the anchor) and make adjustments to it to reach their estimate – it influences the way people intuitively assess probabilities
In other words, it is a cognitive bias that describes the tendency to rely too heavily on the first piece of information offered when making decisions. Once the anchor is set, future decisions are made by adjusting away from that anchor

Question 6

What is Gambler’s Fallacy?

Answer 6

A logical fallacy involving the mistaken belief that past events will affect future events when dealing with independent events

Question 7

What are heuristics?

Answer 7

Simple, efficient rules people use to make judgements and decisions (e.g. rule of thumb; mental shortcuts; educated guesses) - Pattern recognition and rely on subconscious integration of patient data with prior experience => decision made quickly and subconsciously

Question 8

What is availability heuristics?

Answer 8

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 weight their judgments towards more recent information
Example: a clinician who recently missed the diagnosis of pulmonary embolism in a healthy young woman who had vague chest discomfort but no other clinical findings or apparent risk factors might then overestimate the risk in similar patients and become more likely to do CT pulmonary angiography for similar patients despite the very small probability of disease.

Question 9

What is representativeness heuristics?

Answer 9

Subjective probability that a stimulus belongs to a particular class based on how typical of that class it appears
Being typical does not necessarily make something belong/not belong to a group --> this should be up to base probability 
Useful in real life but can be dangerous in medicine       "

Question 10

Give an example of when representativeness heuristics can be dangerous in medicine

Answer 10

e.g. several hours of vague chest discomfort in a thin, athletic, healthy-appearing 60-yr-old man who has no known medical problems and who now looks and feels well does NOT match the typical profile of an MI, however, it would be unwise to dismiss that possibility because MI is common among men of that age and has highly variable manifestations

Question 11

State some strategies for improving clinical decision-making.

Answer 11

• Recognise that heuristics and biases may be affecting our judgement even though we may not be conscious of them
• Counteract the effect of top-down processing by generating alternative theories and looking for evidence to support them rather than just looking for evidence that confirms our preferred theory (confirmatory bias)
• Understand and employ statistical principles e.g. Bayes’theorem
• Use of algorithms and decision support systems”