Literature search and study selection
Medline, Embase, Web of Science and Scopus were searched from conception to September 2022. Search strategies are shown in Appendix S1. Review article references were also screened.
Titles and abstracts were screened independently by two authors (TB; SJ) using EndNote-X9 and duplicate or irrelevant studies removed.29 Full texts were screened and justification for inclusion or exclusion recorded, differences were resolved by discussion with the senior author (AR).
We included published peer reviewed studies reporting accuracy estimates to predict pelvic endometriosis (peritoneal; ovarian; or invasive disease >5mm retroperitoneal invasion) for one or more index tests in participants with reported presence/absence of endometriosis. Included tests were dysmenorrhoea; pelvic pain; dyschezia; dyspareunia; nulligravidity; BMI ≥30kg/m2; family history of endometriosis; transvaginal ultrasound finding (TVUSS) of endometrioma; TVUSS finding of invasive disease; and serum CA-125 >35U/mL.
Target population was reproductive age women excluding pregnancy or systemic co-morbidities. Studies reporting non-reproductive age participants were included only where their data could be excluded from meta-analysis. Studies were included where a 2x2 contingency table for index test(s) could be constructed. We imposed no limits to language, setting, or number of participants. All non-English studies were translated by a medically trained native speaker.
Studies reporting laboratory tests and imaging were included only when performed prior to reference standard and with ultrasound using only standard 2D protocols. Definitions for each test for the purposes of study selection are shown in Appendix Table 1.
We excluded reviews; case reports; studies where information on recruitment or study population was unavailable; letters; and abstracts. Studies reporting non-pelvic endometriosis were included only where pelvic endometriosis was reported separately. Authors were contacted only to obtain full texts or, failing this, they were obtained through the British Library. Studies with incomplete data preventing determination of inclusion, exclusion or test accuracy were excluded.