Table 2 Risk of bias assessment using Phase 3 of the QUADAS-2 tool
Domain | Item | Population-based, single-gate | High-risk,single-gate | Other | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
Barnetson 2006 [16] | Southey 2005 [23] | Poynter 2008a [21] | Caldes 2004 [17] | Mueller 2009 [19] | Overbeek 2007 [20] | Poynter 2008 a [21] | Shia 2005 [22] | Hendriks 2003 [18] | ||
Patient selection | Was a consecutive or random sample of patients enrolled? | Y | Y | U | U | U | U | U | U | U |
Was a case-control design avoided? | Y | Y | Y | Y | Y | Y | Y | Y | Nb | |
Did the study avoid inappropriate exclusions? | Y | Y | U | Y | U | U | U | U | Y | |
Could the selection of patients have introduced bias? | L | L | U | U | U | U | U | U | Uc | |
Is there concern that the included patients do not match the review question? | L | L | L | L | L | L | L | L | L | |
Index test | Were the index test results interpreted without knowledge of the results of the reference standard? | U | U | U | U | U | U | U | U | U |
If a threshold was used, was it pre-specified? | U | U | U | U | U | U | U | U | U | |
Could the conduct or interpretation of the index test have introduced bias? | U | U | U | U | U | U | U | U | U | |
Is there concern that the index test, its conduct, or interpretation differ from the review question? | L | L | L | L | L | L | L | L | L | |
Reference standard | Is the reference standard likely to correctly classify the target condition? | Y | Y | Y | Y | Y | Y | Y | Y | Y |
Were the reference standard results interpreted without knowledge of the results of the index test? | U | U | U | U | U | U | U | U | Y | |
Could the reference standard, its conduct, or its interpretation have introduced bias? | U | U | U | U | U | U | U | U | L | |
Is there concern that the target condition as defined by the reference standard does not match the review question? | L | L | L | L | L | L | L | L | L | |
Flow and timing | Was there an appropriate interval between index test(s) and reference standard? | U | U | U | U | U | U | U | U | U |
Did all patients receive a reference standard? | Y | N | N | Y | Y | Y | Y | Y | Y | |
Did patients receive the same reference standard? | Y | N | N | N | U | U | N | N | U | |
Were all patients included in the analysis? | N | N | N | N | Y | U | N | U | N | |
Could the patient flow have introduced bias? | U | U | U | U | U | U | U | U | U | |