Data extraction and quality assessment
For each included study, two authors (TB; SJ) independently recorded information on study characteristics and data was extracted to form 2x2 tables. Where there was unreliability in data extraction from some non-English language studies, these were excluded.
Risk of bias and applicability was assessed independently by two authors (TB; SJ) using the Quality Assessment of Diagnostic Test Accuracy Studies (QUADAS 2) tool.30 For studies regarding serum CA-125 or TVUSS we included the additional signalling questions: ‘was the index test performed by a single operator?’ to assess inter-observer bias; and ‘was timing in the participants’ menstrual cycle controlled for?’. We adjusted the original question ‘if a threshold was used, was it pre-specified?’ to ‘was there a clear definition of what was considered a positive test?’.