Proposals for a phased evaluation of medical tests.

Background: In drug development, a 4-phase hierarchical model for the clinical evaluation of new pharmaceuticals is well known. Several comparable phased evaluation schemes have been proposed for medical tests.
Purpose: To perform a systematic search of the literature, a synthesis, and a critical review of phased evaluation schemes for medical tests.
Data Sources: Literature databases of Medline, Web of Science, and Embase.
Study Selection and Data Extraction: Two authors separately evaluated potentially eligible papers and independently extracted data.
Results: We identified 19 schemes, published between 1978 and 2007. Despite their variability, these models show substantial similarity. Common phases are evaluations of technical efficacy, diagnostic accuracy, diagnostic thinking efficacy, therapeutic efficacy, patient outcome, and societal aspects.
Conclusions: The evaluation frameworks can be useful to distinguish between study types, but they cannot be seen as a necessary sequence of evaluations. The evaluation of tests is most likely not a linear but a cyclic and repetitive process.