7943 Modification of the “Aagl Endometriosis Classification” to a 3-Stage System: Diagnostic Accuracy & Inter-Observer Reproducibility Study

Abstract

<h3>Study Objective</h3> We aim to assess the performance of a modified AAGL (mAAGL) endometriosis classification system and its inter-observer reproducibility. <h3>Design</h3> Retrospective diagnostic accuracy & inter-observer reproducibility 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> Patients with complete surgical data included. The original 4-stage American Association of Gynecologic Laparoscopists (AAGL) staging system was modified to three stages by merging AAGL stages 2 and 3 and surgical complexity levels B and C. Three observers independently apportioned an AAGL stage 1-3, blinded to surgical skill level (A, B and C). End points were diagnostic performance of each observer to predict level of surgical complexity for each stage, i.e., mAAGL stage 1 to predict level A, mAAGL stage 2 to predict level B, mAAGL stage 3 to predict level C. Inter-observer reproducibility was assessed using OR of a higher grade, between each pair of observers. <h3>Measurements and Main Results</h3> 272 surgical cases analyzed. The diagnostic accuracy for all observers to predict each level in terms of sensitivity, specificity, PPV and NPV were: stage 1 to predict level A: 98.0-98.7%, 60.2-64.2%, 75.0-76.9% & 96.3-97.5%; stage 2 to predict level B: 31.1-36.9%, 97.0-98.2%, 86.5-92.6% & 69.8 – 71.9%; stage 3 to predict level C: 90.0-95.0%, 90.1-91.7%, 41.8 - 47.5% & 99.1-99.6%. Inter-observer reproducibility between observer 1 & 2 was 0.81, between observer 1 & 3 was 0.69 and between observer 2 & 3 was 0.43. Overall percentage agreement between observers 1 & 2 was 93.4%, between 1 & 3 was 93.4% & between 2 & 3 was 96.3%. <h3>Conclusion</h3> The mAAGL system appears to perform well for both low and high stage endometriosis disease. The 4-stage AAGL staging system could be improved by merging AAGL stages 2 and 3 and in turn using a 3-stage system.