7919 External Validation of the Recently Published “Aagl 2021 Endometriosis Classification” Staging System

Abstract

<h3>Study Objective</h3> We aim to externally validate the "2021 AAGL Endometriosis Classification" system. <h3>Design</h3> A multicenter, retrospective, diagnostic accuracy study. <h3>Setting</h3> 2 gynecology units in metropolitan Sydney, Australia. <h3>Patients or Participants</h3> Patients with suspected endometriosis who underwent laparoscopy between January 2016 and October 2021 (n=272). <h3>Interventions</h3> Databases from three previous research studies were examined. Patients with comprehensive coded surgical data were identified. All patients were staged surgically by three assessors, according to the 2021 American Association of Gynecologic Laparoscopists (AAGL) classification staging tool. The AAGL 4-level surgical complexity scale was used as the validation tool. <h3>Measurements and Main Results</h3> 272 surgical cases were analyzed. Breakdown of surgical complexity levels were as follows: A 149 (54.8%), B 23 (8.5%), C 80 (29.4%) and D (20 (7.4%). The diagnostic accuracy for all observers to predict each level in terms of sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were: stage 1 to predict level A = 97.9-98.7%, 60.2-64.2%, 75.0-76.9% & 96.3-97.5%; stage 2 to predict level B = 26.1-30.4%, 93.2-95.6%, 26.3-35.3% & 92.9-93.6%; stage 3 to predict level C = 7.5-10.0%, 93.8-94.8%, 33.3-42.1% & 70.9-71.5%; stage 4 to predict level D = 90.-95.0%, 90.1-91.7% &, 41.9-47.5% & 99.1-99.6%. For all three assessors, AUROC for A vs B/C/D (cut-point 9) 0.75-0.88, A/B vs C/D (cut-point 16) 0.81 and A/B/C vs D (cut-point 22) 0.95-0.96. <h3>Conclusion</h3> This external validation study demonstrates that the highest AAGL stage performs reasonably well for the prediction of surgical complexity, albeit with low NPV. However, the three lower stages perform poorly. The AUROC scores for AAGL stage to discriminate surgical complexity levels was less promising than in the original publication of the staging tool. This is the first external validation study of the AAGL 2021 classification system. The results suggest that in its current form, it is not generalizable.