“…In particular, 5 of the included studies did not report details of patient selection [29,31,32,35,43], and 4 provided unclear information on patient selection [30,40,48,50], resulting in a high and unclear bias in patient selection. Moreover, the threshold was not prespecified in one study [39], leading to a high risk of bias in the index test, and 8 studies provided unclear information on how to perform the index test [30,[34][35][36][37][38]42,46], leading to an unclear risk of bias. Furthermore, one study interpreted the results of reference standards when the results of the index test were known [41], leading to a high risk of bias in the reference standard, and another did not explain this [28], which was considered to be an unclear risk of bias.…”