Yang 2006.

Methods	Location: Harbin, China No. of centres: one Recruitment period:March 2002 to March 2004
Participants	Inclusion criteria: women with stage 3 endometriosis who had undergone conservative or semi‐conservative surgery, with normal renal function and blood count, aged 23 to 42 Exclusion criteria: history of hypertension, heart disease, diabetes mellitis, had undergone hormone therapy in 6 months prior to surgery No. randomised: 52 No. analysed: unclear
Interventions	Post‐operative Gr A (n=20): yiweining (YWN) 200 ml orally twice daily, for 3 months, starting on 7th post‐operative day Gr B (n=19): gestrinone 2.5 mg twice weekly, SC? for 3‐6 months, starting on 7th post‐operative day Gr C (n=13): control ‐ no treatment
Outcomes	Pregnancy, recurrence of endometriosis, adverse effects
Notes	Power calculation: not stated Funding: Fund of National Science of Heilongjiang Province Email sent to corresponding author requesting additional information April 2010 ‐ mailbox not found
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"randomly divided" ‐ no details of method of sequence generation given
Allocation concealment (selection bias)	Unclear risk	not mentioned
Blinding (performance bias and detection bias) All outcomes	High risk	not mentioned, no placebo used
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	not clear how many of the randomised patients are included in the outcomes (% only given)
Selective reporting (reporting bias)	Unclear risk	pregnancy and recurrence reported ‐ no details as criteria for measuring these
Other bias	Low risk	groups are similar in age and type of surgery at baseline

NS = not stated 
 IM = intramuscular

SC = subcutaneous