Table 2.
Detailed QUADS-2 tool assessment after the two reviewers reached a consensus.
| Authors and year | Patient selection | Index test | Reference standard | Flow and timing |
|---|---|---|---|---|
| Cho et al. 2018 | The experiment was designed to be a retrospective study and did not include a random sample. However, the study avoided inappropriate exclusion (high risk) | The index test results were interpreted knowing the results of the reference standard. It was unclear whether a prespecified threshold was used (high risk) | It was unclear whether the reference standard was likely to classify the target condition accurately. The reference standard results were interpreted knowing the results of the index test (low risk) | It was unclear whether there was an appropriate interval between the index test and reference standard and whether all patients were included in the analysis. All patients received a reference standard, but it is unclear whether it was the same reference standard (unclear) |
|
| ||||
| Tian et al. 2018 | The experiment was designed to be a retrospective study and did not include a random sample. However, the study avoided inappropriate exclusion (high risk) | The index test results were interpreted knowing the results of the reference standard. However, a pre specified threshold was used (high risk) | The reference standard was likely to classify the target condition accurately. The reference standard results were interpreted without knowing the results of the index test (low risk) | It was clear whether there was an appropriate interval between the index test and reference standard. All patients received a reference standard, but it was unclear whether it was the same reference standard. Not all patients were included in the analysis (low risk) |
|
| ||||
| Hashido et al. 2018 | The experiment was designed to be a retrospective study and did not include a random sample. However, the study avoided inappropriate exclusion (high risk) | The index test results were interpreted without knowing the results of the reference standard. Furthermore, a pre specified threshold was used (low risk) | The reference standard was likely to classify the target condition accurately. The reference standard results were interpreted without knowing the results of the index test (low risk) | It was unclear whether there was an appropriate interval between the index test and reference standard. All patients received a reference standard, but it was unclear whether it was the same reference standard. Not all patients were included in the analysis (unclear) |
|
| ||||
| Vamvakas et al. 2019 | The experiment was designed to be a retrospective study and did not include a random sample. In addition, it was unclear whether the study avoided inappropriate exclusion (high risk) | The index test results were interpreted knowing the results of the reference standard. It was unclear whether a prespecified threshold was used (high risk) | The reference standard was likely to classify the target condition accurately. The reference standard results were interpreted knowing the results of the index test (high risk) | It was unclear whether there was an appropriate interval between the index test and reference standard and included all patients in the analysis. All patients received a reference standard, but it was unclear whether it was the same reference standard (unclear) |
|
| ||||
| Zhao et al. 2020 | The experiment was designed to be a retrospective study and did not include a random sample. In addition, it was unclear whether the study avoided inappropriate exclusion (high risk) | The index test results were interpreted without knowing the results of the reference standard. However, it was unclear whether a prespecified threshold was used (low risk) | It was unclear whether the reference standard was likely to classify the target condition accurately. The reference standard results were interpreted without knowing the results of the index test (low risk) | It was unclear whether there was an appropriate interval between the index test and reference standard. All patients received a reference standard, but it was unclear whether it was the same reference standard. Not all patients were included in the analysis (unclear) |