Study selection and characteristics
Of 22,016 studies identified 125 met the inclusion criteria involving 250,574 participants (Figure 1). Characteristics of included and excluded studies are shown in Table S1. Details of included studies by number of participants and index test(s) are shown in Appendix Table 1.
Mean number of index tests per study was 2 (range 1-6). A total of 241 were assessed across all studies. Included studies were geographically varied: 45 from Europe, 34 North America, 19 Asia/Oceania, 13 the Middle East/Africa, 12 South America, and 2 transcontinental. Publication date ranged from 1986 to 2022 with 57% since 2010: 4 before 1989; 22, 1990-1999; 18, 2000-2009; and 71, 2010-2022.
Most studies (75) were ‘single-gate’ design with 50 of ‘two-gate’ design, including all studies in the partial verification and database/self-reporting groups. The mean prevalence of endometriosis in studies of a ‘single-gate’ design was 52% (range 9-93%), due to the selection of matched controls, prevalence in ‘two-gate’ studies was not relevant. There was heterogeneity in population selection, with participants having surgery for a broad range of indications such uterine fibroids or adnexal cysts as well as pelvic pain or sub-fertility.
In the 61 studies assessing symptom-based tests 20 did so by self-administered questionnaire; 14 by structured interview; 12 by clinical history taking, and 15 were undefined.