[Benefits, costs and analysis in diagnostic radiology: definitions and glossary]

Cost efficiency analyses in clinical radiology require the application of methods and techniques that are not yet part of the academic qualifications of the specialists. The procedures used are borrowed from economics, decision theory, applied social sciences, epidemiology and statistics. Many expressions hail from the angloamerican literature and are presently not yet germanized unequivocally. This survey is intended to present main terms of cost efficiency analysis in the english version as well as a german translation, to give a clear definition and, if necessary, explanatory notes, and to illustrate their application by means of concrete radiologic examples. The selection of the terms is based on the hierarchical models of health technology assessment resp. clinical outcome research by Fryback & Thornbury resp. Maisey & Hutton. In concrete terms, both the differences between benefit, outcomes, and utility and the differences between effectiveness, efficacy and efficiency and the differences between direct, indirect, intangible, and marginal costs are explained. True cost efficiency analysis is compared with cost effectiveness analysis, cost identification analysis, cost minimization analysis, and cost utility analysis. Applied social sciences are represented by the Medical Outcomes Study Short Form-36 and the QALY conception. From decision theory both the analysis of hypothetical alternatives and the Markov model are taken. Finally, sensitivity analysis and the procedures of combined statistical evaluation of comparable results (meta-analysis) are quoted.