Clinical Decision Making Clinicians are prone to a wide range of cognitive errors and biases in clinical judgment situations.  Only by being aware of this susceptibility and taking steps to address it can a clinician be as effective a decision maker as possible. Decision aids – be they actuarial formulas, treatment manuals, etc., are an effective means of limiting such bias and error.

Clinical Versus Actuarial Prediction  Two approaches to making decisions: Reliance on clinical “expertise” and intuition.  This is by far the preference of clinicians Practitioners tend to have strong belief in the value of their own experience Use of actuarial decision aids  Use of formula based on empirically established relations Note – such formula don’t exclude clinician judgments if those judgments have value

Clinical Versus Actuarial Prediction  Meehl (1954) first raised the issue and established conditions for fair comparisons  More than 100 studies to date Evidence overwhelmingly favors actuarial approaches.  Experienced clinicians are no more accurate than novices

Why Don’t Clinicians Develop the Expertise They Believe They Have  So why doesn’t experience bring much improvement in clinical judgmental accuracy? Cognitive biases and errors (universal to human beings – not specific to clinicians)  Such biases and errors are often a result of relying on judgment heuristics (shortcuts) that often work well in everyday life, but which may lead to errors in clinical judgment Such errors are most likely under conditions of INFORMATION OVERLOAD  Information overload: situation in which there is a large amount of information and no way to determine what is important and what is not Precisely the situation in clinical assessment

A Sampling of Important Cognitive Biases and Errors  Confirmatory Bias - a tendency to search for or interpret new information in a way that confirms one's preconceptions and avoid information and interpretations which contradict prior beliefs.  Illusory Correlation - the phenomenon of seeing the relationship one expects in a set of data even when no such relationship exists.  Availability Bias - a biased prediction, due to the tendency to focus on the most salient and emotionally-charged outcome.

A Sampling of Important Cognitive Biases and Errors (cont.)  Hindsight Bias - the inclination to see past events as being predictable.  Overpathologizing Bias – a tendency to assume the presence of pathology (similar to confirmatory bias)  Overconfidence - the tendency to overestimate one's own abilities