2. Clinical Decision Making Flashcards
What are medical errors? Give examples.
“An error is defined as the failure of a planned action to be completed as intended (i.e., an error of execution) or the use of a wrong plan to achieve an aim (i.e., an error of planning).”
For example 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
What are the causes of medical errors?
One hundred cases of diagnostic error were evaluated to identify system-related and cognitive factors underlying error using record reviews
Define confirmatory bias
Give an example
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
Example: someone who supports the legalisation of marijuana will seek out information and stories that support his/her argument
What is the sunk cost fallacy?
Sunk costs are any costs that have been spent on a project that is irretrievable ranging including anything from money spent building a house too expensive drugs used to treat a patient with a rare disease.
- Rationally the only factor affecting future action should be the future costs/benefits ratio but humans do not always act rationally and often the more we have invested in the past the more we are prepared to invest in a problem in the future, this is known as the Sunk Cost Fallacy.
•Bornstein et al (1999) found that medical residents’ evaluation of treatment decisions was not influenced by the amount of time and/or money that had already been invested in treating a patient.
- However, the residents did demonstrate a sunk-cost effect in evaluating non-medical situations.
What is anchoring? What is the anchoring effect?
- Individuals poor at adjusting estimates from a given starting point (probs. & values)
- Adjustments crude & imprecise
- Anchored by starting point
Anchoring and adjustment – a psychological heuristic (cognitive shortcut that may result in a suboptimal outcome) that influences the way people intuitively assess probabilities.
§ Per this heuristic, people start with the implicitly suggested reference point (the “anchor”) and adjust it to reach their estimate (adjustments).
o I.E. A price of an item says “Reduced from £100 to £50” then we think this is a great deal (even if it’s not worth £50) as the anchor is £100.
§ Heuristic – fast and frugal approaches to thinking.
What is the gambler’s fallacy? Give an example
A logical fallacy involving the mistaken belief that past events will affect future events when dealing with independent events
Example: having another go on the fruit machine because you’ve lost the last 5 times so you’re probably going to win something next time
What is the use of probability in clinical decision making?
What is the framing effect?
When presented with treatment descriptions, described in positive, negative or neutral terms:
- Older adults – more likely to agree to the treatment described in positive terms as opposed to neutrally or negative.
What are heuristics?
“Rules of thumb, educated guesses, mental shortcuts”
- Involve pattern recognition and subconscious integration of patient data with prior experience
What are availability heuristics? Give an example
- 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 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.
What is representativeness heuristics? Give an example.
- The 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 this is often very useful in daily life, it can also result in neglect of relevant base rates and other errors
- Example: 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
What are the strategies for improving clinical decision-making?
- Recognize that heuristics and biases may be affecting our judgment even though we may not be conscious of them
- Counteract the effect of top-down information processing by generating alternative theories and looking for evidence to support them rather than just looking for evidence that confirms our preferred theory.
- Understand and employ statistical principles e.g. Bayes Theorem
- Use of Algorithms and decision support systems
What can be done about cognitive errors and heuristics?
How can decision making be improved?
What are algorithms and their uses?
Algorithm – a logical series of steps to take to decide most effectively, but not necessarily most efficiently.
