Quality assessment (risk of bias)
All included studies will be assessed for risk of bias and their
applicability based on the QUADAS 2 instrument12. The
four key domains covering patient selection, index test, reference
standard (comparator), and flow and timing will be evaluated. Any
studies deemed to have a high risk of bias i.e. scoring ‘high’ for three
or more of the four risk of bias domains, or concerns regarding
applicability i.e. scoring ‘high’ for two or more of the three
applicability domains will be excluded from further meta-analyses.