Strengths and Limitations
This retrospective study used descriptive data rather than laparoscopic images to simulate endometriosis staging, and therefore might not be as representative as real time intraoperative staging. A prospective study where scoring and staging is performed in the usual contemporaneous fashion would overcome this. The three assessors in this study were either MIGS or fellows in their final year of MIGS training, and data were obtained from tertiary pelvic pain referral centres. Selection bias has been identified as a challenge in endometriosis research (22), whereby sample populations recruited to studies are not always representative of the 11% (23) of the female population that suffer from endometriosis. These findings therefore might not be generalizable to general gynaecology clinics and generalist obstetricians and gynaecologists who might use this tool, for example.
A strength of our study was the use of a consensus process to reduce heterogeneity between assessors interpreting the AAGL system. The rationale for this was that the authors identified several potential areas of ambiguity within the tool. While this improved consistency between the three assessors in this experiment, it does not necessarily represent the real-world application of endometriosis staging tools. In addition, the fact that three observers were used and the best of three results was considered for discussion demonstrates that all due effort was made assess the AAGL system fairly. Bias was mitigated by blinding between observers, and also between the staging and skill level allocations.