Biomarkers

A biomarker is broadly defined as a substance that can be measured and evaluated as an indicator of normal or pathogenic biologic processes or of a biologic response to a therapy or intervention. In epidemiology, biomarkers are often used to measure internal dose, biologically effective dose, early [Page 86]biologic response, altered structure or function, and susceptibility. By incorporating biomarkers into epidemiologic assessments, researchers may more precisely measure exposures or outcomes, reduce exposure and/or disease misclassification to produce less biased estimates of association, and elucidate biologic processes underlying exposure-disease relationships. The increasing integration of biomarkers in epidemiologic studies has fostered the creation of a distinct multidisciplinary subspecialty called molecular epidemiology in which molecular, cellular, and other biologic measurements are incorporated into cross-sectional, retrospective, and prospective observational ...