Laboratory test selection.

One of the most frequent and perhaps frustrating problems in laboratory medicine today relates to the appropriate selection of laboratory tests. We all know that many laboratory tests are not always selected with care and results are not used to benefit the patient. If unnecessary tests are performed, then the laboratory is providing little or no new information to the clinician. This is costly and time consuming for the laboratory and wasteful of health care resources. In addition, unnecessary tests will serve to complicate the diagnostic process and adversely affect medical decision making. While precision and accuracy have been long standing concerns for the laboratorian, it is clear that our perspective about the tests we perform must be broadened if we are going to keep up with the changing pace of health care. The selection, interpretation and evaluation of laboratory tests can be facilitated by the use of some newer concepts in laboratory medicine They include sensitivity, specificity and predictive value. These concepts will be introduced together with examples of their application.