Reference change values- how useful are they?
- Fierdoz Omar (fierdoz.omar{at}uct.ac.za)
- George Frederick van der Watt (george.vanderwatt{at}uct.ac.za)
Abstract
Clinicians use several approaches in the interpretation of laboratory results. These include comparison with pre-determined cut-off values or reference values, or a comparison between two sequential results for a specific analyte1. Each has its own merits. The latter is the focus of this editorial.
A simple comparison between two sequential results is not as straightforward as it seems. It should be remembered that each result is associated with its own inherent random variation, meaning that each result obtained is, in fact, a dispersion rather than a singular value. This random variation is comprises both variation associated with laboratory activity (pre-analytical and analytical variation) and inherent biological variation (intra-individual).
