Tsai 2004.

Methods	Location: Taiwan No. of centres: one Recruitment period: June 1988 to December 2001
Participants	Inclusion criteria: women of reproductive age with infertility and stage III or IV endometriosis planning to undergo controlled ovarian hyperstimulation and intrauterine insemination or in vitro fertilisation and embryo transfer. All had surgery for endometriosis ‐ either laparotomy or laparoscopy for cystectomy, adhesiolysis, ablation of endometriosis Exclusion criteria: NS No. randomised: 45 No. analysed: 41
Interventions	Post‐operative medical therapy (either danazol or GNRH analogue) Gr A (n=15 ): either 3 months 400 mg danazol orally, twice daily for 3 months or 3.75 mg leuprolide acetate depot SC every 28 days for 3 months Gr B (n= 30): no post‐operative medical treatment
Outcomes	Pregnancy rate, recurrence
Notes	Power calculation: NS Funding: NS
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"simple randomisation with a computer generated list unknown to physicians"
Allocation concealment (selection bias)	Low risk	list "unknown to physicians"
Blinding (performance bias and detection bias) All outcomes	High risk	not mentioned, no placebo
Incomplete outcome data (attrition bias) All outcomes	High risk	4 lost to follow up from Gr A (27%)
Selective reporting (reporting bias)	Low risk	pregnancy and recurrence reported
Other bias	Unclear risk	13 years of recruitment ‐ ? associated changes in surgical techniques over this time