Table 3 Quality analysis by QUADAS tool of all studies included

1.

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

Y

Y

Y

Y

U

Y

Y

Y

Y

Y

Y

2

Were selection criteria clearly described?

U

Y

N

N

U

U

N

Y

Y

Y

Y

3.

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

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

4.

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?

U

Y

U

U

U

U

Y

U

Y

Y

Y

5.

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

Y

Y

U

Y

Y

Y

Y

Y

Y

Y

Y

6.

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

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

7.

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

Y

Y

U

U

U

U

U

Y

Y

U

Y

8.

Was the execution of the index test described in sufficient detail to permit replication of the test?

N

N

N

N

N

N

N

N

N

N

N

9.

Was the execution of the reference standard described in sufficient detail to permit its replication?

N

N

Y

N

N

Y

N

Y

N

N

Y

10.

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

U

U

U

U

U

U

U

U

Y

U

U

11.

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

U

U

U

U

U

U

U

U

Y

U

U

12.

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

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

13.

Were uninterpretable/intermediate test results reported?

N

N

N

N

N

N

N

N

N

N

N

14.

Were withdrawals from the study explained?

N

Y

N

Y

N

N

N

N

Y

Y

N