Diagnostic Studies

Abstract

Abstract Diagnostic studies are performed to investigate the clinical usefulness of a new diagnostic procedure, for example, a new contrast agent for imaging or a new laboratory test to detect antibodies or antigens in blood. Sometimes, these studies are invented to substitute the standard procedure by an improved or less expensive procedure, which is not inferior in terms of efficacy and has some benefit compared with the standard procedure. Before starting a diagnostic study, first the unit for analysis should be defined in the terms “experimental unit” and “observational unit.”