3.3.2 | Index test
Four studies[33, 34, 36, 37] had a high ROB in this area because they did not use a preset threshold for identifying positive results. Four studies[31, 32, 35, 38] had an unclear ROB in this area because they did not report whether they interpreted indicator test results without knowledge of the OFC results. Only one study had a low ROB in this area[30].
3.3.3 | Reference standard
One study[33], in which some patients did not undergo OFC, was therefore rated as having unclear ROB in this area, and its applicability to the research questions in this review was rated as uncertain.
3.3.4 | Patient flow and timing
One study[35] specified a time to compare the metrics for all patients with the interval of the reference trial based on the same reference criteria that were included in the analysis of the data for all patients and were therefore classified as having a low ROB in this area; the remaining seven studies[30-32, 34, 36-38] failed to meet at least one of the criteria and were therefore scored as having an unclear ROB. One study[33] was rated as high ROB for flow and timing due to different reference tests between participants, some patients in the same group received DBPCFC while others were administered by OFC, and the other part did not receive OFC.
Table 1 Main characteristics of included studies
3.4 | Diagnostic accuracy of CRD
3.4.1 |