Cost and effectiveness of clinical investigation: The state of the art

Clinical investigation by means of special technical tests has increased in clinical practice during recent years. Pressures causing this increase are said to include: rapid technological change making many more tests available, clinical uncertainty, peer pressure, greater patient awareness, and concern for diagnostic completeness. Cost factors do not appear to have influenced test-ordering behaviour to any large extent, and those ordering investigations are frequently ignorant of the cost of the tests which they are ordering, both to the patient and the community. The relation of clinical investigational activity to quality of outcome of patient care remains largely unestablished. Studies of the possible modification of test-ordering behaviour through educational and institutional policy pressures are reviewed. A rational approach to investigating the effectiveness of techniques designed to encourage the more economic and effective use of investigations is presented in brief on the basis of this review of previously published work.