Shaw 2001.

Methods	Location: UK and Republic of Ireland No. of centres: 7 Recruitment period: not stated
Participants	Inclusion criteria: 18‐50 year old women referred for symptom management or infertility Exclusion criteria: cervical intraepithelial neoplasia (CIN) No. randomised: 48 No. analysed: 40
Interventions	Pre‐operative goserelin versus no treatment Gr A (n=21 ): goserelin 3.6 mg SC monthly for 3 months pre‐operatively Gr B (n=27 ): no medical therapy
Outcomes	Change in endometrioma size, recurrence, pregnancy
Notes	Power calculation: yes Funding: Astra Zeneca, Macclesfield, UK
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	participants were stratified by endometrioma size and "randomly allocated using computer generated randomization lists"
Allocation concealment (selection bias)	Unclear risk	not mentioned
Blinding (performance bias and detection bias) All outcomes	High risk	not mentioned, no placebo
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	33%(7) and 41% (11) of patients in Gr A & B withdrew from trial before surgery. Reasons given but are different in each group. 4 withdrawals from goserelin group pre surgery due to serious AE ‐ migraine/headache/hot flushes, groin pain, muscle cramps, pain iliac fossa/sciatica. However all patients are included in outcome evaluation provided there is >1 post baseline measurement of endometrioma, but these numbers are not stated
Selective reporting (reporting bias)	Low risk	primary outcome is change in size of endometrioma, range of other outcomes including ease of surgery and pregnancy reported
Other bias	Unclear risk	some differences between the groups at baseline in mean endometrioma size. Difficulty in recruiting patients made trial underpowered, with different numbers in each group