Advances in Dental Research, Vol 8, 92-99, Copyright © 1994 by International & American Associations for Dental Research
Biological markers: their use in quantitative assessments
M. F. Vine
Department of Epidemiology, School of Public Health, University of North Carolina, Chapel Hill 27599-7400.
Biological markers can be conceptualized in terms of categories of markers
that form a continuum representing a sequence of events from exposure to
disease. These categories include markers of internal dose, biologically
effective dose, early response, and disease. Outside of this sequence are
susceptibility factors that can act at any point along the way to modify
the effects of external exposures on disease outcomes. Examples of the use
of these different types of markers in epidemiologic research are provided.
There are many factors that one must consider when selecting a biological
marker for use in an epidemiologic study. These factors include: the
objectives of the study, the availability and specificity of potential
markers, the feasibility of measuring the markers in various biological
media, the invasiveness of the techniques necessary to measure the markers,
the amount of biological specimen needed for analysis, the time to
appearance of the markers in the biological media, the persistence of the
markers in biological media, the variability of marker levels within and
between individuals, the stability of markers in storage, as well as the
cost, sensitivity, specificity, and reliability of the assays used to
measure the markers. Each of these characteristics is discussed. The
usefulness of biological markers in an epidemiologic study depends on the
objectives of the study and whether the properties of the markers fulfill
the objectives of the study in a feasible and cost-effective manner.
