Table 1 The assessment items of methodological quality of studies

Judgments on Bias

 Patient selection

1. Was a consecutive or random sample of patients enrolled?

2. Did the control group include other respiratory diseases?

3. Did the study include appropriate exclusions?

 Index test

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

2. If a threshold was used, was it pre-specified?

 Reference standard

1. Is the reference standards likely to correctly classify the target condition?

2. Were the reference standard results interpreted without knowledge of the results of the index tests?

 Flow and timing

1. Was there an appropriate interval between index test and reference standard?

2. Did all patients receive the same reference standard?

3. Were all patients included in the analysis?

Applicability

 Patient selection

Are there concerns that the included patients and setting do not match the review question?

 Index test

Are there concerns that the index test, its conduct, or its interpretation differ from the review question?

 Reference standard

Are there concerns that the target condition as defined by the reference standard does not match the question?