LAUSR

This paper introduced the Quality Assessment of Diagnostic Accuracy Studies-Comparative (QUADAS-C), illustrated the comparison with the QUADAS-2, and using QUADAS-C together with QUADAS-2 to present QUADAS-C results through systematic reviews. Like the domain for QUADAS-2, QUADAS-C retained four domains, including patient selection, index test, reference standard, flow, and timing, and comprised additional questions for each QUADAS-2 part. Unlike the QUADAS-2 tool, the starting question of each domain for QUADAS-C was designed to summarize the risk of biased information captured by QUADAS-2. QUADAS-C only dealt with the risk of bias but did not include the part of concerns regarding applicability. The answers to signaling questions for each domain of QUADAS-C would lead to a 'low''high' or 'unclear' risk of biased judgment for the original study.