Current concepts of "normal values," "reference values," and "discrimination values," in clinical chemistry.

The term "normal values" is seriously afflicted by sylleptic ambiguities and conceptual problems, and it is gradually being discarded from the lexicon of clinical chemistry. The neutral term "reference values" preferable on semantic and scientific grounds, and its use in clinical chemistry is rapidly gaining acceptance. The term "discrimination value" has been added to the lexicon of clinical chemistry. Use of the "discrimination value" for the results of a laboratory test in a specified clinical situation provides the optimal discrimination between the "healthy" and the "diseased," or between "those who need not be investigated further" and "those who do."