1853 Learning Curve for the Detection of Pouch of Douglas Obliteration and Deep Endometriosis of the Rectum in Gynecology Trainees

Abstract

Study Objective Evaluate the learning curve of gynecology trainees to correctly classify pouch of Douglas (POD) obliteration state and identify rectal deep endometriosis (DE) in real-time while simultaneously performing and interpreting transvaginal ultrasound (TVS). Design Learning curve using the cumulative sum (LCCUSUM) prospective study. Setting A tertiary healthcare center in Sydney, Australia. Patients or Participants Three observers of varying pre-study ultrasound experience. Interventions Observers performed a pre-determined 150 supervised examinations (50 each) to asses for POD obliteration and rectal DE, having been blinded to the clinical history and reference standard findings. Immediate feedback and hands-on teaching were provided. Measurements and Main Results The acceptable performance rate (proficiency) was set at 15% failure, the unacceptable performance rate was set at 30%, and the equivalence zone was set at 5%. 150 examinations were performed on 145 patients, with rectal DE in 26 (17.3%) and negative sliding sign in 34/145 (22.7%). The overall accuracy of presence or absence of rectal DE was 90%, ranging from 82-94% amongst the observers. The overall accuracy of POD state classification was 92.7%, ranging from 90-96% amongst the observers. LCCUSUM for rectal DE demonstrated observer 1 did not reach proficiency, whereas observers 2 and 3 required 21 and 25 scans, respectively. For POD obliteration, observer 2 did not reach proficiency, whereas observers 1 and 3 required 40 and 22 scans, respectively. Conclusion One gynecology trainee became proficient in diagnosing rectal DE and POD obliteration in less than the 50 planned supervised ultrasounds. Contrary to similar studies, we propose that not all trainees can reach proficiency during a program based upon a pre-defined number of scans and competency-based education may be more appropriate.