Bergqvist 1998.

Study characteristics
Methods	Trial design: "Prospective, randomised, placebo‐controlled, double‐blind, parallel study"
Participants	Participants: 49 women eligible; 49 were randomised and 46 were analysed Age: mean of 31 years (19‐44years) Stage: most mild‐to‐moderate (IV n = 1) Inclusion criteria: Menstruating regularly 3 months before study Clinical symptoms of endometriosis Not taken oral contraceptive or oral steroid therapy for 3 months Not taken long‐acting depot gestagens or GnRHas within past 6 months Not pregnant in prior 3 months Not breastfeeding No history of osteoporosis or coagulation disorders Exclusion criteria: Intraperitoneal adhesions making visual inspection and careful evaluation of the extension of endometriotic lesions difficult or impossible Setting: Sweden Timing: Not stated
Interventions	Triptorelin 3.75 mg IM depot every 4 weeks for 24 weeks (n = 24) versus Placebo IM every 4 weeks for 24 weeks (n = 25)
Outcomes	Relief of overall pain Adverse effects Visible endometriosis extension rAFS Frequency and amount of bleeding Serum concentrations of estradiol
Notes	Intention‐to‐treat analysis: not stated Sample size calculation: not stated Funding: not stated Note previous version: Needs raw score for pain. Authors contacted and awaiting response
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No details were provided of method used to generate the randomisation sequence.
Allocation concealment (selection bias)	Unclear risk	No details were provided of method used to conceal treatment group allocation.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Participants and researchers were blinded through the use of identical kits for injections.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Participants and researchers were blinded through the use of identical kits for injections.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Three participants withdrew from the study. Two from the placebo group (1 prior to the first injection due to pregnancy, and one after 4 months due to lack of effect), and one from the triptorelin group due to hypoestrogenic side effects and depression.
Selective reporting (reporting bias)	Low risk	The study protocol was not available but it was clear that the published reports included all expected outcomes, including those that were prespecified.
Other bias	Low risk	No other risk of bias detected