Predicting clinical states in individual patients. Ann Intern Med

A probability model expresses the relation between the presence of clinical findings (input or independent vari-ables) and the probability that a clinical state will occur (the dependent variable); for example, it expresses the probability that a disease is present or will develop or the probability that an outcome state will be reached. Proba-bility models are developed by using selected study groups. Although these models are most often used to make predictions for groups of patients, they can also predict clinical states for individual patients. The following seven criteria provide a basis for the critical appraisal of probability models. In particular, phy-sicians can use these criteria to decide when a specific probability model should be used to make a prediction in an individual patient. Five of the criteria are concerne