The risky business of studying prognosis.

Prognosis studies provide important healthcare information. Clinicians use prognostic factors to predict disease progress, thus allowing individualization of disease management. Prognosis is the issue in many translational studies that aim to identify biomarkers to predict outcomes. In a clinical trial, researchers may use prognostic factors to sort patients into risk groups, to clarify the effects of a new therapeutic agent. Prognosis studies can have significant effects on clinical practice.