[Normal ranges and accuracy of laboratory analyses].
For many reasons, it is impossible to make a distinction between the laboratory indices of health and disease (to establish the normal ranges); there is always an uncertainty portion wherein the result of an analysis allows the conclusion to be made only with a definitive probability. The real uncertainty (i.e. inaccuracy) of an analysis extends this portion. The generally recognized recommendations on blood glucose and cholesterol should be taken as a model, which identifies three zones: 1) health; 2) disease; and 3) intermediate one when well-being cannot be stated, but a significant disease is absent. The uncertainty of the result of analysis is best assessed by the statistical shift scattering method that characterizes the wide spectrum of not only analytical, but also some preanalytical errors. The ranges of normal values (a reference interval) established by a traditional population-based study may be taken only as interim ones, by introducing the half-width intermediate zone of one shift scatter.
D019411:Clinical Laboratory Techniques / Q000592:standards*; D006801:Humans; D012016:Reference Values; D015203:Reproducibility of Results