ABSTRACT
A useful medical test must satisfy a variety of criteria, including identifying disease that is serious, prevalent in the target population, and treatable; and that the test is not harmful to the individual and is accurate (1–4). An exception is the need for accurate diagnosis of some infectious diseases without serious morbidity in the host or effective treatments, as this diagnosis may aid in the prevention of transmission to others in whom morbidity may vary. This chapter describes the last criterion alone, the accuracy of the test.
