BACKGROUND: A quality assessment tool for diagnostic accuracy studies, namedQUADAS, has recently been developed. Although QUADAS has been used in severalsystematic reviews, it has not been formally validated. The objective was toevaluate the validity and usefulness of QUADAS.METHODS: Three reviewers independently rated the quality of 30 studies usingQUADAS. We assessed the proportion of agreements between each reviewer and thefinal consensus rating. This was done for all QUADAS items combined and for each individual item. Twenty reviewers who had used QUADAS in their reviews completed a short structured questionnaire on their experience of QUADAS.RESULTS: Over all items, the agreements between each reviewer and the finalconsensus rating were 91%, 90% and 85%. The results for individual QUADAS itemsvaried between 50% and 100% with a median value of 90%. Items related touninterpretable test results and withdrawals led to the most disagreements. Thefeedback on the content of the tool was generally positive with only smallnumbers of reviewers reporting problems with coverage, ease of use, clarity ofinstructions and validity.CONCLUSION: Major modifications to the content of QUADAS itself are notnecessary. The evaluation highlighted particular difficulties in scoring theitems on uninterpretable results and withdrawals. Revised guidelines for scoring these items are proposed. It is essential that reviewers tailor guidelines forscoring items to their review, and ensure that all reviewers are clear on how to score studies. Reviewers should consider whether all QUADAS items are relevant totheir review, and whether additional quality items should be assessed as part of their review.
Evaluation of QUADAS, a tool for the quality assessment of diagnostic accuracy studies
Rutjes A;
2006-01-01
Abstract
BACKGROUND: A quality assessment tool for diagnostic accuracy studies, namedQUADAS, has recently been developed. Although QUADAS has been used in severalsystematic reviews, it has not been formally validated. The objective was toevaluate the validity and usefulness of QUADAS.METHODS: Three reviewers independently rated the quality of 30 studies usingQUADAS. We assessed the proportion of agreements between each reviewer and thefinal consensus rating. This was done for all QUADAS items combined and for each individual item. Twenty reviewers who had used QUADAS in their reviews completed a short structured questionnaire on their experience of QUADAS.RESULTS: Over all items, the agreements between each reviewer and the finalconsensus rating were 91%, 90% and 85%. The results for individual QUADAS itemsvaried between 50% and 100% with a median value of 90%. Items related touninterpretable test results and withdrawals led to the most disagreements. Thefeedback on the content of the tool was generally positive with only smallnumbers of reviewers reporting problems with coverage, ease of use, clarity ofinstructions and validity.CONCLUSION: Major modifications to the content of QUADAS itself are notnecessary. The evaluation highlighted particular difficulties in scoring theitems on uninterpretable results and withdrawals. Revised guidelines for scoring these items are proposed. It is essential that reviewers tailor guidelines forscoring items to their review, and ensure that all reviewers are clear on how to score studies. Reviewers should consider whether all QUADAS items are relevant totheir review, and whether additional quality items should be assessed as part of their review.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
