Medical guidelines may not always be compatible with laboratory practice
Michel R. Langlois, MD, PhD
Dept. of Laboratory Medicine, AZ St-Jan Bruges, and University of Ghent, Belgium.
Medical guidelines on the use of in vitro diagnostic biomarkers are usually based on population studies that assessed the diagnostic performance of the biomarker (with a certain analytical method). However, these guidelines and the recommended cut-off values of the biomarker may not always be universally applicable, e.g., due to lack of standardization and between-method/between-laboratory variability. Often the recommended biomarkers are not completely validated according to essential criteria for medical use: analytical performance, clinical (diagnostic) performance, clinical- and cost-effectiveness. In the example of medical guidelines for cardiovascular disease prevention, LDL-cholesterol targeted strategies are based on population studies using the older precipitation methods and, therefore, not validated for use of the contemporary direct (homogeneous) assays.