Irahara 2001.

Study characteristics
Methods	Trial design: Randomised controlled trial
Participants	Participants: 21 women were randomised and analysed. Mean age:   Group 1: 36.0 ±10.0 years, group 2: 35.5 ± 8.6 years Inclusion criteria: Negative smear and negative mammogram in 6 months prior to the start of the study No previous hormonal treatment received for endometriosis Exclusion criteria: not stated Setting: Japan Timing: not stated
Interventions	Group 1: monthly injection of 3.75 mg leuprolide acetate depot (n = 10) versus  Group 2: monthly injection of 3.75 mg leuprolide acetate + 0.625 mg conjugated equine oestrogen + 2.5 mg medroxyprogesterone acetate every other day from 2nd month of GnRHa treatment (n = 11)
Outcomes	Bone mineral density Laboratory results
Notes	Intention‐to‐treat analysis: not stated Sample size calculation: not stated Funding: not stated Author contacted for further information; awaiting response
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomised controlled trial. No further details of method used to generate the randomisation sequence were provided.
Allocation concealment (selection bias)	Unclear risk	No details of method used to conceal allocation were provided.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	No details provided of blinding of participants or personnel
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No details provided of blinding of outcome assessment
Incomplete outcome data (attrition bias) All outcomes	Low risk	No losses to follow‐up
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