Petta 2005.

Study characteristics
Methods	Trial design: multi‐centre randomised, controlled clinical trial
Participants	Participants: 83 women were randomised; 71 were analysed. Mean age: LNG‐IUS = 29.4 ± 4.8 years and Lupron depot = 30.5 ± 6.4  years Inclusion criteria: Laparoscopically and histologically confirmed endometriosis within 3 to 24 months prior to study enrolment 18‐40 years old Complaints of cyclic chronic pelvic pain with or without dysmenorrhoea VAS pain score of greater or equal to 3 during the pretreatment cycle Regular menstrual cycle of 25‐35 days for at least 3 months prior to study Exclusion criteria: Hormone treatment within 3 months of entering study Long acting progestins or GnRHa within 9 months prior to study Pregnant or breastfeeding within 3 months prior to study Osteoporosis, coagulation disorders or contraindications to LNG‐IUS Setting: Brazil ( 3 centres) Timing: February 2002 to May 2004
Interventions	LNG‐IUS (Mirena) 20 mcg/day 5 years IU for 6 months (n = 39) versus Lupron 3.75 mg every 28 days IM for 6 months (n = 43)
Outcomes	Pain as defined by VAS score Psychological general well‐being index
Notes	Intention‐to‐treat analysis: Data analysis did not follow intention‐to‐treat principles but included only those women who had completed the VAS pain diary correctly throughout the entire study period of 6 months (n = 71). Sample size calculation: yes Funding:The levonorgestrel‐releasing intrauterine system (Mirena) and GnRH analogue ampoules were provided free of charge by Schering, Sao Paulo, Brazil. Note previous version: Authors contacted regarding data; awaiting response
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation was by "computer generated system". Three centres participated in the study and randomisation was performed separately for each centre.
Allocation concealment (selection bias)	Unclear risk	"sealed envelopes" were used to conceal allocation to treatment groups.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	"Blinding of participants would not have been possible due to nature of the intervention". No details provided of blinding of participants or personnel
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Outcome assessors were blinded according to author.
Incomplete outcome data (attrition bias) All outcomes	Low risk	"data analysis did not follow intention‐to‐treat principles" but details given for attrition: 6 each from both groups withdrew 1 pregnant and 5 did not complete pain diary (LNG‐IUS) 6 did not complete pain diary (Lupron)
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