Creus 2008

Methods	Randomised controlled trial
Participants	Infertile women with mild to moderate endometriosis (n = 104) post‐laparoscopic surgery Inclusion criteria: at least 12 months with asymptomatic primary infertility, regular menstruation, aged between 23 and 37 years with normal BMI. Women with other infertility factors were included if those factors were correctable and were non‐contributory Exclusion criteria: women with other pelvic disorders such as adhesions and tubal obstructions in addition to endometriosis
Interventions	1. Pentoxifylline 400 mg: 1 tablet twice a day (n = 51) 2. Placebo (n = 53) Other procedures given post‐laparoscopy included biopsies, tubal dye perfusion and destruction of endometriotic implants by cautery Treatment was started with the first menses after laparoscopic surgery; then participants were observed for 6 months. During this time, participants with other infertility factors were treated (e.g. male problems or ovulatory defects). Treatments included IUI or ovulation induction, or both. Not all participants were treated or received the same treatment, thus the potential for bias.
Outcomes	Pregnancy Miscarriage
Notes	6 women dropped out: 4 from the treatment group and 2 from the control group. Reasons explained. No ITT. Trial held in Barcelona, Spain Work supported in part by the Comissionat per Universitat i Recerca‐Generalitat de Catalunya Authors were also involved in Balasch 1997 Author emailed 23rd November 2011 regarding live birth data. No reply.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Computer‐generated randomisation list generated using the method of simple randomisation".
Allocation concealment (selection bias)	Low risk	"Concealment of treatment allocation was achieved with the use of sealed opaque envelopes, each containing a unique study number and prepared independently by a secretary".
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Trial was blinded, not stated whether single, double or triple; "randomised controlled blind trial".
Incomplete outcome data (attrition bias) All outcomes	Low risk	Small numbers of dropouts and reasons explained, no ITT
Selective reporting (reporting bias)	Low risk	Outcomes reported
Other bias	Unclear risk	Some women with other fertility issues apart from endometriosis were treated for these additional conditions (i.e. male factor (receiving bromocriptine), oligo‐ovulation (receiving ovulation induction and some additional IUI), poor post‐coital test, hyperprolactinaemia). Numbers of women in treatment and control in each of these categories are given. However, treatments may bias the results, as nearly double the control women in the additional treatment group received IUI compared with the treatment group