Fig. 2.

Summary of QUADAS-2 assessments of included studies.

Patient selection: describes methods of patient selection; index text: describes the index test and how it was conducted and interpreted; reference standard: describes the reference standard (gold standard test) and how it was conducted and interpreted; flow and timing: describes any patients who did not receive the index tests or reference standard or who were excluded from the 2 × 2 table, and describes the interval and any interventions between index tests and the reference standard [30].