Table 1.

Items of assessment in QUADAS.

Items	Assessment	Questions
Q1	Adequate spectrum composition	Was the spectrum of patient’s representative of the patients who will receive the test in practice?
Q2	Clear description of selection criteria	Were selection criteria clearly described?
Q3	Adequate reference standard	Is the reference standard likely to correctly classify the target condition?
Q4	Absence of disease progression bias	Is the period between reference standard and index test short enough to be reasonably sure that the target condition did not change between the 2 tests?
Q5	Absence of partial verification bias	Did the whole sample or a random selection of the sample, receive verification using a reference standard of diagnosis?
Q6	Absence of differential verification bias	Did patients receive the same reference standard regardless of the index test result?
Q7	Absence of incorporation bias	Was the reference standard independent of the index test (i.e. the index test did not form part of the reference standard)?
Q8	Adequate description of the index test execution	Was the execution of the index test described in sufficient detail to permit replication of the test?
Q9	Adequate description of the reference test execution	Was the execution of the reference standard described in sufficient detail to permit its replication?
Q10	Absence of index test review bias	Were the index test results interpreted without knowledge of the results of the reference standard?
Q11	Absence of reference test review bias	Were the reference standard results interpreted without knowledge of the results of the index test?
Q12	Absence of clinical review bias	Were the same clinical data available when test results were interpreted as would be available when the test is used in practice?
Q13	Report of uninterpretable results	Were uninterpretable/intermediate test results reported?
Q14	Description of withdrawals	Were withdrawals from the study explained?