Table 2

QUADAS-2 appraisal form

Lead author of included studiesKobayashiMasciCampbellYamane
Domain 1: patient selection
Was a consecutive or random sample of patients enrolled?YesUnclearUnclearUnclear
Was a case-control design avoided?YesYesYesYes
Did the study avoid inappropriate exclusions?YesYesYesYes
Could the selection of patients have introduced bias?LowUnclearUnclearUnclear
Are there concerns that the included patients do not match the review question?LowLowUnclearLow
Domain 2: index test
Were the index test results interpreted without knowledge of the results of the reference standard?YesYesYesUnclear
Did the study provide a clear definition of what was considered to be a ‘positive’ result?YesUnclearYesUnclear
Could the conduct or interpretation of the index test have introduced bias?LowUnclearLowUnclear
Are there concerns that the index test, its conduct, or interpretation differ from the review question? High LowLowLow
Domain 3: reference standard
Is the reference standard likely to correctly classify the target condition? No YesYes No
Were the reference standard results interpreted without knowledge of the results of the index tests? No YesYesUnclear
Did the study provide a clear definition of what was considered to be a ‘positive’ result?YesUnclearYesYes
Could the reference standard, its conduct, or its interpretation have introduced bias? High UnclearLow High
Are there concerns that the target condition as defined by the reference standard does not match the question? High LowLow High
Domain 4: flow and timing
Was there an appropriate interval between index test and reference standard?UnclearYesYesYes
Did all patients receive a reference standard? No YesYesYes
Did patients receive the same reference standard (protocol)?YesYesYesYes
Did patients receive the same index test (protocol)?YesYes No Yes
Were all patients included in the analysis?YesYesYes No
Could the patient flow have introduced bias? High Low High High
  • In each domain: signalling questions (white background) are followed by summarising questions of ROB and applicability concerns (light grey background).