In individuals with a confirmed diagnosis, the presence or level of a prognostic biomarker is used to identify the likelihood of a clinical event, disease recurrence or progression, independent of the effects of a specific intervention. 

Prognostic biomarkers may be used to refine criteria for disease diagnosis or staging. A biomarker may be both prognostic and predictive.

Example

• CD4+ lymphocyte count in individuals with human immunodeficiency virus, to identify those at elevated risk of progression to Acquired Immunodeficiency Syndrome.