7.3. Critical appraisal of diagnostic accuracy studies

For the quality appraisal of diagnostic accuracy studies, the QUADAS 2 instrument is recommended (Whiting, 2003). The tool is structured so that 4 key domains are each rated in terms of the risk of bias and the concern regarding applicability to the research question. Each key domain has a set of signalling questions to help reach the judgments regarding bias and applicability. A background document on QUADAS 2 can be found on the website: http://www.bris.ac.uk/quadas/quadas-2.

In order to correctly appraise a diagnostic accuracy study, basic knowledge about key concepts is essential. An overview of these concepts is provided in the following table:

Three phases can be distinguished in the QUADAS tool:

• Phase 1: State the review question using the PIRT format (Patients, Index test(s), Reference standard, Target condition)
• Phase 2: Draw a flow diagram for the primary study, showing the process of recruiting, inclusion, exclusion and verification
• Phase 3: Risk of bias and applicability judgments.

 The score can be filled in using the template in attachment.