Cost effectiveness of multiphasic screening: old controversies and a new rationale.

The cost effectiveness of multiphasic screening is evaluated from a conceptual as well as from a practical viewpoint. Conceptual analysis includes a consideration of the technical sensitivity and specificity of the tests used, of the prevalences of the screened diseases, and of the costs and values associated with different outcomes of screening. Practical considerations include the potential of multiphasic screening for increasing productivity, for reassuring patients, and for reducing morbidity and mortality. Although all these issues can be cogently formulated, at present none can be documented by a comprehensive set of data leading to irrefutable conclusions. Therefore, the issue of who should be screened continues to be obfuscated by controversy and prejudice. To resolve this dilemma a new rationale for the use of multiphasic screening is developed. This is based on a small number of uncontroversial facts and leads to practical proposals relating to how standards for useful test batteries can be constructed.