WIA Biomarker Data Standard Guide

A number becomes a biomarker only when we know what was measured, how, in whom, and what decision it is meant to support. This chapter builds that vocabulary and shows where each part of WIA-BIO-004 fits.

A laboratory analyser that prints "CRP 12.5 mg/L" has produced a measurement. It has not yet produced clinical knowledge. To turn that number into something a physician can act on, several further facts are needed: the assay that generated it, the specimen it came from, whether the specimen was haemolysed or left on the bench too long, the interval of values seen in comparable healthy people, and, above all, the question the result is supposed to answer. Is it being used to diagnose an acute infection, to monitor an inflammatory disease under treatment, or to estimate long-term cardiovascular risk? The same analyte, measured on the same analyser, plays a different role in each case and must be judged by different evidence.