prognostic

Prognostic is an adjective used to describe factors, indicators, or approaches that relate to prognosis—the forecast of the likely course and outcome of a disease or condition. In clinical settings, prognostic information helps clinicians estimate survival, risk of progression, or likelihood of specific events such as relapse, independent of treatment. A prognostic factor is any patient characteristic or disease attribute that is associated with the outcome of interest; common examples include age, stage of disease, performance status, tumor grade, and molecular markers. Molecular or genetic features can serve as prognostic markers or be incorporated into multivariable prognostic models or scores, which combine several factors to estimate an individual’s risk.

These models are distinct from diagnostic factors, which indicate the presence of disease, and from predictive factors, which indicate the likely effect of a particular treatment. Prognostic information is used to stratify patients into risk groups, guide treatment choices, and inform patients about their expected disease course. Development and application of prognostic models require validation in independent populations and attention to calibration and discrimination; overfitting and population differences can limit generalizability.

Beyond medicine, prognostic principles also appear in other fields such as engineering, where prognostics estimate the remaining useful life of a component or system. Etymologically, prognostic derives from prognosis, the forecast of the likely outcome.