Table 3 QUADAS ratings

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

N

Y

N

Y

2. Were selection criteria clearly described?

Y

Y

Y

Y

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

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 2 tests?

Y

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

Y

Y

6. Did patients receive the same reference standard regardless of the index text result?

Y

Y

Y

Y

7. Was the reference standard independent of the index test (ie, the index test did not form part of the reference standard)?

Y

Y

Y

Y

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

Y

Y

Y

Y

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

Y

Y

Y

Y

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

N

Y

Y

Y

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

N

Y

N

Y

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

13. Were interpretable/intermediate test results reported?

Y

Y

Y

Y

14. Were withdrawals from the study explained?

Y

Y

Y

Y

Total quality score

11

14

12

14