Inter-observer reproducibility of the 2021 AAGL Endometriosis Classification

Jason Nicholas Mak; Cansu Uzuner; Mercedes Espada; Allie Eathorn; Shannon Reid; Mathew Leonardi; Mike Armour; George Stanley Condous

doi:10.1111/ajo.13851

Inter-observer reproducibility of the 2021 AAGL Endometriosis Classification

Aust N Z J Obstet Gynaecol. 2024 Jun 19. doi: 10.1111/ajo.13851. Online ahead of print.

Authors

Jason Nicholas Mak¹, Cansu Uzuner¹, Mercedes Espada^{2

3}, Allie Eathorn⁴, Shannon Reid^{5

6}, Mathew Leonardi⁷, Mike Armour⁸, George Stanley Condous^{1

3

9}

Affiliations

¹ Acute Gynaecology, Early Pregnancy, and Advanced Endosurgery Unit, Nepean Hospital, Penrith, New South Wales, Australia.
² Department of Obstetrics and Gynaecology, Blue Mountains District ANZAC Memorial Hospital, Katoomba, New South Wales, Australia.
³ OMNI Ultrasound & Gynaecological Care, Sydney, New South Wales, Australia.
⁴ Medical Research Institute of New Zealand, Wellington, New Zealand.
⁵ Department of Obstetrics and Gynaecology, Western Sydney University, Sydney, New South Wales, Australia.
⁶ Department of Obstetrics and Gynaecology, Campbelltown Private Hospital, Sydney, New South Wales, Australia.
⁷ Department of Obstetrics and Gynecology, McMaster University, Hamilton, Ontario, Canada.
⁸ NICM Health Research Institute, Western Sydney University, Sydney, New South Wales, Australia.
⁹ Sydney Medical School Nepean, The University of Sydney, Penrith, New South Wales, Australia.

PMID: 38896105
DOI: 10.1111/ajo.13851

Abstract

Background: Inter-observer agreement for the American Association of Gynecologic Laparoscopists (AAGL) 2021 Endometriosis Classification staging system has not been described. Its predecessor staging system, the revised American Society for Reproductive Medicine (rASRM), has historically demonstrated poor inter-observer agreement.

Aims: We aimed to determine the inter-observer agreement performance of the AAGL 2021 Endometriosis Classification staging system, and compare this with the rASRM staging system.

Materials and methods: A database of 317 patients with coded surgical data was retrospectively analysed. Three independent observers allocated AAGL surgical stages (1-4), twice. Observers made their own interpretation of how to apply the tool in the first staging allocation. Consensus rules were then developed for a second staging allocation.

Results: First staging allocation: odds ratio (OR) (and 95% CI) for observer 1 to score higher than observer 2 was 8.08 (5.12-12.76). Observer 1 to score higher than observer 3 was 12.98 (7.99-21.11) and observer 2 to score higher than observer 3 was 1.61 (1.03-2.51). This represents poor agreement. Second staging allocation (after consensus): OR for observer 1 to score higher than observer 2 was 1.14 (0.64-2.03), observer 1 to score higher than observer 3 was 1.81 (0.99-3.28) and observer 2 to score higher than observer 3 was 1.59 (0.87-2.89). This represents good agreement.

Conclusions: These findings suggest that in its current format the AAGL 2021 Endometriosis Classification staging system has poor inter-observer agreement, not superior to the rASRM staging system. However, performance improved when additional measures were taken to simplify and clarify areas of ambiguity in interpreting the staging system.

Keywords: endometriosis; laparoscopic surgery; observer variation.

© 2024 The Author(s). Australian and New Zealand Journal of Obstetrics and Gynaecology published by John Wiley & Sons Australia, Ltd on behalf of Royal Australian and New Zealand College of Obstetricians and Gynaecologists.