Equivocal notions of accuracy and genetic screening of the general population.

The explosive growth in genetic technology quickly will make possible an unprecedented number of tests for genetically based conditions. A necessary condition for the use of such tests without risk of harm to the patient is their accuracy. However, most discussions of test accuracy in the literature have equivocated between two importantly different meanings of the word. In particular, it must be remembered that a high analytic accuracy does not imply a high diagnostic accuracy. Questions about the diagnostic accuracy of genetic tests presently loom large because of our limited knowledge of the complex etiology of disease and the distribution within the general population of the causal factors involved. Our current inability to supply patients with accurate diagnosis based on genetic information, however, is less problematic when examined in the context of new reproductive technologies such as in vitro fertilization and intraplasmic sperm injection.