4.6.2      Assessment of methodological quality table

Please note: This section only describes QUADAS, but RevMan 5.2 also supports QUADAS-2. It was not possible to include an updated Handbook in this version of RevMan, but you can check the Diagnostic Test Accuracy Working Group website for all the latest Handbook chapters. For basic guidance on using QUADAS-2 in RevMan, see the RevMan Help file.

 

This table is used to record the methodological quality of each study.  The table contains eleven predefined quality assessment items from the QUADAS tool (see Table 4.6.b).  These items are strongly recommended, but can be deleted in exceptional circumstances when not relevant.  In addition it is possible to enter custom quality items by creating ‘user defined’ fields.  Details of how to edit the table can be found in RevMan5 Help.  Full details of how to assess quality and how to decide which quality items to assess can be found in Chapter 9

 

For each item in the quality assessment the author must enter both a description of how the study addressed the issue, and a classification as to whether this was adequate (‘yes’), inadequate (‘no’), or whether not enough detail was presented for a judgement to be made (‘unclear’).  For both the standard and the user defined items details of the criteria for classifying studies as ‘yes’, ‘no’ and ‘unclear’ must be stated in the review protocol, probably using an additional table (see Section 4.6.1.7).

 

It is possible to attribute quality assessments either to a study, or to each test within each study.  In the former, all tests within a study are classified the same way, in the latter, tests within the same study can have different quality assessments.  In RevMan5 this is described as ‘by test’ or ‘by study’.  It is possible to specify a mixture of ‘by test’ and ‘by study’ quality assessment items within a review.  For details of how to define the quality assessment table please refer to RevMan5 Help.

 

 

Table 4.6.b: Guide to the contents of the Assessment of methodological quality table

 

Representative spectrum?

Was the spectrum of patients representative of the patients who will receive the test in practice?

Acceptable reference standard?

Is the reference standard likely to correctly classify the target condition?

Acceptable delay between tests?

Is the time period between reference standard and index test short enough to be reasonably sure that the target condition did not change between the two tests?

Partial verification avoided?

 

Did the whole sample or a random selection of the sample, receive verification using a reference standard of diagnosis?

Differential verification avoided?

 

Did patients receive the same reference standard regardless of the index test result?

Incorporation avoided?

 

Was the reference standard independent of the index test? (i.e. the index test did not form part of the reference standard).

Reference standard results blinded?

 

Were the index test results interpreted without knowledge of the results of the reference standard?

Index test results blinded?

 

Were the reference standard results interpreted without knowledge of the results of the index test?

Relevant clinical information?

 

Were the same clinical data available when test results were interpreted as would be available when the test is used in practice?

Uninterpretable results reported?

 

Were uninterpretable/ intermediate test results reported?

Withdrawals explained?

 

Were withdrawals from the study explained?