Chapter III

In total, 224 patients (124 surgery, 100 medication) were recruited between May 2019-May 2023. Participants/materials, setting, methods We recruited patients with ovarian endometrioma of ≥3cm and pain. Those with deep endometriosis (DE) were not eligible.

Surgical approach was guideline-based. Medication comprised hormonal therapy and/or analgesics. In both groups, continuation or initiation of (hormonal) medication was allowed.

The primary outcome was ≥30% pain reduction (numeric rating scale: NRS) at 6 months. Secondary outcomes were, among others, change in NRS and QoL (EHP-30). Treatment effects were estimated using augmented inverse probability weighting (AIPW), targeting the average treatment effect and reported as adjusted risk difference (RD) and marginal odds ratio (OR).

Main results and the role of chance After six months, ≥30% pain reduction was achieved in 76% after surgery versus 62% after medication (marginal OR: 1.83, 95% CI 1.0 to 3.3, P=0.047). Pelvic pain and dysmenorrhea scores at six months were lower following a surgical management, whereas no statistically significant difference was observed for dyspareunia. QoL improved in both groups, favoring surgery in four subscales.

Limitations, reasons for caution The RCT was prematurely discontinued after 22 inclusions, resulting in a predominantly patient preference cohort with potential for residual confounding. Specific surgical and medical treatment strategies were heterogeneous, and follow-up was limited to six months. Wider implications of the findings The observed benefits of surgical management, with or without adjunctive medication, at six months should be considered alongside patient preferences and the benefits and risks of both treatment strategies.

It remains unclear whether these effects are sustained over time. Key words Endometrioma, pain, quality of life, dysmenorrhea, dyspareunia