Table 1 Quality assessment of included studies using ‘QUADAS’ questionnaire
QUADAS questionnaire | Abdullah et al. 2012 [ 13 ] | Parente et al. 2012 [ 14 ] | Mulder et al. 2007 [ 10 ] | Hardt et al. 2004 [ 15 ] | Koss et al. 2007 [ 16 ] | Tonus et al. 2006 [ 17 ] | Shastri et al. 2008 [ 11 ] | Haug et al. 2007 [ 18 ] |
|---|---|---|---|---|---|---|---|---|
Was the spectrum of participants representative of the patients who will receive the test in practice? | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
Were selection criteria clearly described? | Yes | Yes | Yes | No | Yes | Yes | Yes | Yes |
Was the reference standard likely to classify the target condition correctly? | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
Was the period between performance of the reference standard and the index test short enough to be reasonably sure that the target condition did not change between the two tests? | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
Did the whole sample or a random selection of the sample receive verification using the reference standard? | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
Did participants receive the same reference standard regardless of the index test result? | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
Was the reference standard independent of the index test? (That is, the index test did not form part of the reference standard) | No | Yes | Yes | Yes | Yes | No | Yes | Yes |
Was the execution of the index test described in sufficient detail to permit its replication? | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
Was the execution of the reference standard described in sufficient detail to permit its replication? | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
Were the index test results interpreted without knowledge of the results of the reference standard? | No | Unclear | Yes | No | No | No | No | No |
Was the reference standard results interpreted without knowledge of the results of the index test? | No | No | No | No | No | Unclear | Yes | Unclear |
Were the same clinical data available when the test results were interpreted as would be available when the test is used in practice? | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
Were un-interpretable, indeterminate or intermediate test results reported? | No | Yes | Yes | No | No | No | Yes | Unclear |
Were withdrawals from the study explained? | Unclear | Yes | Yes | No | No | No | Yes | Unclear |