Memorandum for the evaluation of diagnostic measures.

In contrast to therapeutic methods no general guidelines have as yet been formulated for the investigation of diagnostic measures. Previous studies have often delivered results that have not been interpretable. This situation was obviously unsatisfactory since staff, apparatus and financial resources were not being meaningfully employed. For these reasons the present memorandum was drawn up by a working group of the GMDS. It is intended to provide a framework for the evaluation of diagnostic measures. The process for the evaluation of diagnostic tests has by analogy to the procedure for the registration of drugs been divided into four clearly defined phases: Phase 1: preliminary technical and methodological investigations; Phase 2: estimation of test parameters in selected patients; Phase 3: Controlled diagnostic study; Phase 4: Investigation of the effectiveness; continuing risk-benefit analysis. Studies on new diagnostic tests should be designed according to the guidelines formulated in this memorandum. Many already established tests will require examination according to the criteria described here.