QUADAS-2

QUADAS-2
Name	QUADAS-2
Purpose	Quality assessment of diagnostic accuracy studies
Developed by	University of Oxford
First published	2011

QUADAS-2 QUADAS-2 is a standard tool for assessing the methodological quality of diagnostic accuracy studies used in systematic reviews and meta-analyses. It provides a structured approach to judge risk of bias and applicability through signaling questions and domain-based judgments, informing evidence syntheses conducted by organizations such as the Cochrane Collaboration, World Health Organization, National Institute for Health and Care Excellence, and academic centers like the University of Oxford and Johns Hopkins University.

Background and development

QUADAS-2 was developed to update and replace earlier checklists during an era when systematic review methods advanced at institutions including the Cochrane Collaboration, Centre for Reviews and Dissemination, National Institute for Clinical Excellence, and research groups at the University of Oxford and University College London. Influential contributors to its methodology drew on precedent tools used by panels involving experts from the World Health Organization, European Commission, National Institutes of Health, and leading academic publishers such as Elsevier and Wiley. The initiative paralleled methodological advances promoted at conferences hosted by bodies like the International Society for Pharmacoeconomics and Outcomes Research and workshops at the Royal Society.

Structure and domains

QUADAS-2 organizes assessment around four primary domains: patient selection, index test, reference standard, and flow and timing, mirroring frameworks used by evidence bodies such as Cochrane Collaboration, National Health Service, European Medicines Agency, and academic centers like Harvard Medical School and Stanford University. Each domain contains signaling questions adapted from concepts applied by committees at the U.S. Food and Drug Administration and panels convened by the World Health Organization. Review teams from institutions such as Imperial College London and McMaster University commonly tailor the signaling questions to match clinical contexts encountered in studies from hospitals like Mayo Clinic, Cleveland Clinic, and research networks including the National Cancer Institute.

Application and scoring

Users apply QUADAS-2 during systematic reviews to classify domains as "low", "high", or "unclear" risk of bias, a judgmental process akin to grading performed by guideline panels from National Institute for Health and Care Excellence, American College of Physicians, and consortia such as the Global Evidence Synthesis Initiative. Scoring relies on predefined signaling questions that echo methods used by groups at Cochrane Collaboration, Johns Hopkins University, and systematic reviewers in institutions like University of Toronto and Karolinska Institutet. Pragmatic application often involves two independent reviewers with arbitration by a third party from organizations such as CONSORT-aligned groups or evidence centers at Oxford University Press.

Strengths and limitations

Strengths of QUADAS-2 include domain-based transparency and adaptability, attributes emphasized by guideline developers at World Health Organization, National Institutes of Health, and research councils like the Medical Research Council. Limitations noted by methodological critics at universities such as Columbia University, University of Sydney, and University of Melbourne include subjectivity in judgments, variability across reviewers from centers like Yale School of Medicine and UCSF, and challenges in summarizing across heterogeneous diagnostic technologies developed by firms such as Roche and Siemens Healthineers. Commentaries in journals associated with publishers like Elsevier and BMJ Publishing Group have discussed these constraints.

Reporting and interpretation

Reporting of QUADAS-2 assessments is often required in systematic review standards promoted by the Cochrane Collaboration, Preferred Reporting Items for Systematic Reviews and Meta-Analyses groups, and guideline developers at National Institute for Health and Care Excellence. Interpretation of domain judgments typically informs subgroup analyses and sensitivity analyses conducted by review teams affiliated with institutions such as Johns Hopkins University, McMaster University, and Imperial College London. Stakeholders including regulators like the European Medicines Agency and funders such as the Wellcome Trust use QUADAS-2–informed syntheses to contextualize diagnostic performance claims from manufacturers including Abbott Laboratories and Thermo Fisher Scientific.

Impact and updates

QUADAS-2 has influenced systematic review methodology at organizations such as the Cochrane Collaboration, World Health Organization, National Institute for Health and Care Excellence, and academic networks across Europe, North America, and Asia. Subsequent methodological work from groups at University of Oxford, McMaster University, and the Cochrane Collaboration has produced guidance on tailoring signaling questions, integrating QUADAS-2 results with meta-analytic techniques used by statisticians at University of Bristol and University of Washington, and prompting proposals for extensions aligned with diagnostic research priorities championed by the National Institutes of Health and the European Commission.

Category:Diagnostic accuracy