ABSTRACT
Using the clinical judgment method of prediction, all gathered information is collected and formulated into a diagnosis or prediction in the clinician's mind. The clinician selects, measures, and combines risk factors and produces risk estimate solely according to clinical experience and judgment. In the actuarial or statistical method of prediction (i.e., statistical prediction rules), information is gathered and combined systematically in an evidence-based statistical prediction formula, and established cutoffs are used.
Clinicians tend to over-estimate exceptions to the established rules (base rate neglect). A clinician's decision is likely to be influenced by past experiences. Clinicians give weight to less relevant information, and often give too much weight to singular variables. Clinicians are susceptible to representative schema biases. Clinicians are exposed to a skewed sample of humanity, and make judgments based on a prototype from their biased experiences. This is known as the representativeness heuristic.
In general, it is better to develop and use structured, actuarial approaches than informal approaches that rely on human or clinical judgment. Actuarial approaches to prediction tend to be as accurate or more accurate than clinical judgment. Nevertheless, clinical judgment tends to be much more widely used than actuarial approaches, which is a major ethical problem.
