Psychology 1b - Clinical Decision Making

Question 1

Define 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).
• E.g. 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.
• Diagnostic errors have the most severe effect on patients

Question 2

Describe the case of WJ

Answer 2

• 15 year old with leukaemia in remission
• Mistakenly, vincristine was administered by intrathecal route rather than IV
• Resulted in paralysis and his parents decided to switch off his life support
• Registrar was convicted of manslaughter

Question 3

Describe Hofling et al’s study

Answer 3

• Doctors asked nurses to administer a higher dose of a fictional drug than a clearly labelled maximum
• 21 out of 22 nurses prepared the dose

Question 4

How is clinical decision making performed?

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.
• Heuristics usually involve pattern recognition and
  rely on a subconscious integration of patient data with prior experience

Question 5

What are the two systems for decision making?

Answer 5

• Hot system - system 1 (emotional, reflexive, fast, develops early, accentuated by stress)
• Cold system - system 2 (cognitive, complex, reflective, slow, develops late, self control)
• System 1 can automatically control actions while system 2 is unaware (Nisbett and Wilson and choosing tights on the right)

Question 6

What is confirmation 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
• Clinically, this can explain misdiagnosis
• Podbregar found conditions who were completely certain of a diagnosis of a patient were incorrect 40% of the time

Question 7

What is the sunk cost fallacy?

Answer 7

• Sunk costs are any costs that have been spent on a project that are irretrievable including expensive drugs used to treat a patient with a rare disease
• The only factor affecting future action should be cost/benefit ratio, but the
  more we have invested in the past the more we are prepared to invest in a
  problem in the future (Sunk Cost Fallacy)
• Bornstein et al found medical residents evaluation of treatment decisions were not influenced by the amount of time and money invested in treating a patient

Question 8

What is anchoring?

Answer 8

• Individuals poor at adjusting estimates from a given starting point
• Adjustments are crude and imprecise
• Anchored by starting point
• Patients may dismiss or excuse conflicting data of their diagnosis

Question 9

What are representativeness heuristics?

Answer 9

• 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.
• Eg. someone may present with symptoms abnormal to a disease, but if that disease is high base rate for a person of that age, they may still have the disease it should not be dismissed

Question 10

Describe the framing effect

Answer 10

• Wording a decision as a loss or gain can affect outcome
• Eg. can be worded as 70% of people get better or 30% of people do not get better
• Older adults are more likely to agree to a treatment when it is positively described, than when described neutrally or negatively

Question 11

What are availability heuristics?

Answer 11

• Probabilities are estimated on the basis of how easily or vividly they can be called to mind
• Individuals typically overestimate the frequency of occurrence of catastrophic, dramatic events (80% believe accidents cause more deaths than strokes)
• People weigh heavily their judgement towards recent information (eg. if a clinician misdiagnoses someone they are more likely to overestimate the risk in similar patients)

Question 12

How can clinical decision making be improved?

Answer 12

• Education and training (teach about cognitive error, diagnostic error, and recognise heuristics and biases)
• Feedback (increase autopsies, conduct regular audits, follow up patients)
• Accountability (establish clear accountability and follow-up for decisions made)
• Generating alternatives (establish consideration of alternatives)
• Consultation (seek second opinions, use algorithms and decision making support systems)

Question 13

What are algorithms?

Answer 13

• Procedures which, if followed exactly, will provide the most likely answer based on the evidence
• Rules of probability are examples of algorithms
• Useful in situations where the problem is well defined (eg. heartburn)
• Have to be taught how to use them

Question 14

List the types of heuristics

Answer 14

• Availability
• Anchoring
• Representativeness