Health Technology Assessment of Diagnostic Tests: A state of the art review of methods guidance from international organisations

OBJECTIVES: To identify which international HTA agencies are undertaking evaluations of medical tests, summarise commonalities and differences in methodological approach, and highlight examples of good practice. METHODS: A methodological review incorporating: systematic identification of HTA guidance documents mentioning evaluation of tests; identification of key contributing organisations and abstraction of approaches to all essential HTA steps; summary of similarities and differences between organisations; and identification of important emergent themes which define the current state of the art and frontiers where further development is needed. RESULTS: Seven key organisations were identified from 216 screened. The main themes were: elucidation of claims of test benefits; attitude to direct and indirect evidence of clinical effectiveness (including evidence linkage); searching; quality assessment; and health economic evaluation. With the exception of dealing with test accuracy data, approaches were largely based on general approaches to HTA with few test-specific modifications. Elucidation of test claims and attitude to direct and indirect evidence are where we identified the biggest dissimilarities in approach. CONCLUSIONS: There is consensus on some aspects of HTA of tests, such as dealing with test accuracy, and examples of good practice which HTA organisations new to test evaluation can emulate. The focus on test accuracy contrasts with universal acknowledgement that it is not a sufficient evidence base for test evaluation. There are frontiers where methodological development is urgently required, notably integrating direct and indirect evidence and standardising approaches to evidence linkage.