Quality assessment using the QUADAS tool
| Domain | Participant selection | Index test | Reference standard | Flow and timing of signs and symptoms |
| Description | Describe methods of participant selection: included participants (prior testing, presentation, intended use of index test and setting). | Describe the index test (symptoms and signs) and how it was conducted and interpreted. | Describe the reference standard and how it was conducted and interpreted. | Describe any participants who did not receive the index test(s) and/or reference standard (diagnostic criteria). Describe the time interval and any interventions between index test(s) and reference standard, that is, any intervention/medication given prior to diagnosis. |
| Signalling questions (yes/no/unclear) | Was a consecutive or random sample of participants enrolled? Was a case-control design avoided? Did the study avoid inappropriate exclusions? | Were the index test results interpreted without knowledge of the results of the reference standard? If a threshold was used, was it prespecified? | Is the reference standard likely to correctly classify the target condition? Were the reference standard results interpreted without knowledge of the results of the index test? | Was there an appropriate interval between index test(s) and reference standard? Did all participants receive a reference standard? Did all participants receive the same reference standard? Were all participants included in the analysis? |
| Risk of bias (high/low/unclear) | Could the selection of participants have introduced bias? | Could the conduct or interpretation of the index test have introduced bias? | Could the reference standard, its conduct or its interpretation have introduced bias? | Could the participant flow have introduced bias? |
| Concerns regarding applicability: (High/low/unclear) | Are there concerns that the included participants do not match the review question? | Are there concerns that the index test, its conduct, or interpretation differ from the review question? | Are there concerns that the target condition as defined by the reference standard does not match the review question? |