Table 1 QUADAS

1.

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

2.

Were selection criteria clearly described?

3.

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

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? (disease progression bias)

5.

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

6.

Did patients receive the same reference standard regardless of the index test result? (differential verification bias)

7.

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

8.

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

9.

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

10.

Were the index test results interpreted without knowledge of the results of the reference standard? (test review bias)

11.

Were the reference standard results interpreted without knowledge of the results of the index test? (diagnostic review bias)

12.

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

13.

Were uninterpretable/ intermediate test results reported?

14.

Were withdrawals from the study explained?