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QUADAS-2 Tool for Diagnostic Accuracy Studies

Record QUADAS-2 risk of bias and applicability judgements for each diagnostic accuracy study, and download the traffic light and summary plots for your review.

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Domains and how to use them
  1. Risk of bias: patient selectionConsecutive or random sampling, avoidance of case-control designs and inappropriate exclusions.
  2. Risk of bias: index testIndex test interpreted without knowledge of the reference standard; threshold pre-specified.
  3. Risk of bias: reference standardReference standard likely to classify the condition correctly and interpreted blind to the index test.
  4. Risk of bias: flow and timingAppropriate interval between tests, same reference standard for all, and all patients analysed.
  5. Applicability: patient selectionWhether the included patients and setting match the review question.
  6. Applicability: index testWhether the index test, its conduct or interpretation differ from the review question.
  7. Applicability: reference standardWhether the target condition defined by the reference standard matches the review question.

Answer the signalling questions in the official tool, then record your judgements here: QUADAS resources (University of Bristol).

Risk of biasApplicability concerns
StudyPSITRSFTPSITRSRisk of biasApplicability
LowLow
HighHigh
HighUnclear
UnclearUnclear

Your entries are saved in this browser only. Nothing is uploaded.

Low only when every domain is low. A study rated high or unclear in any domain is 'at risk of bias' (or has 'applicability concerns'); the summary shows the most severe rating.

Summary plot

Traffic light plot

Risk of biasApplicability concernsStudyPSITRSFTPSITRSRisk of biasApplicabilityExample study 1+++++++++Example study 2×?++×++××Example study 3+??×++?×?Example study 4?++?+?+??+Low?Unclear×High

Summary plot

Risk of bias: patient selection50%25%25%Risk of bias: index test50%50%Risk of bias: reference standard75%25%Risk of bias: flow and timing50%25%25%Applicability: patient selection75%25%Applicability: index test75%25%Applicability: reference standard75%25%Overall risk of bias25%25%50%Overall applicability25%50%25%0%25%50%75%100%LowUnclearHigh
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How to Use the QUADAS-2 Tool

  1. 1

    Answer the official signalling questions

    Use the linked tool document for each study or result.

  2. 2

    Record your judgements

    One row per study, one column per domain; the overall judgement is suggested for you.

  3. 3

    Download the figures

    Traffic light and summary plots as PNG or SVG, plus a CSV of your table.

What is QUADAS-2?

QUADAS-2 assesses the quality of diagnostic accuracy studies in four domains: patient selection, index test, reference standard, and flow and timing. All four are rated for risk of bias, and the first three also for concerns about applicability to the review question.

Judgements are low, high or unclear. A study rated low in every domain can be judged at low risk of bias overall; a high or unclear rating in any domain means it may be at risk of bias.

A modified version of QUADAS-2 is recommended for Cochrane diagnostic test accuracy reviews. Its developers have since released QUADAS-3.

How it is calculated

Sources

QUADAS-2 Tool: FAQ

Should I use QUADAS-2 or QUADAS-3?

Follow your protocol and the guidance for your review type. QUADAS-3 is the newest version; QUADAS-2 is still widely used and recommended in modified form for Cochrane DTA reviews.

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