Defining over- and underuse of laboratory diagnostics: a consensus-oriented E-Delphi study

Laboratory diagnostics are essential for the detection, management, and monitoring of diseases. Most of the clinical decisions are facilitated by the test results of laboratory diagnostics. However, there is a reasonable risk that laboratory diagnostics may be used inappropriately. However, defining this concept is difficult as there is a general lack of consensus on how to define over- and underuse. This complexity is well demonstrated by the great variety in definitions used to classify laboratory diagnostics as being over- or underused, which highlights the need for a clear definition. The objective of this E-Delphi study is to reach a consensus on a definition of over- and underuse of laboratory diagnostics when taking into account the perspectives of the user, provider and, payer in primary and secondary care.