Palomba 2010.

Methods	A randomised controlled trial
Participants	50 women who were CC‐resistant were recruited between February 2003 and May 2004, conducted in 2 university hospitals in Naples, Italy
Interventions	The participants were randomised to clomiphene + metformin (6 cycles) (n = 25) versus LOD alone (n = 25) and followed up for 6 months. LOD was by 3 ‐ 6 punctures of 3 mm diameter and 4 ‐ 5 mm depth, for 2 ‐ 3 seconds at 40 W)
Outcomes	Amenorrhoea at cycle day 35. No operative complications were identified, no drug‐related adverse effects resulting in treatment discontinuation.
Notes	Funding source: "Authorship and contribution to the article is limited to the 8 authors indicated. There was no outside funding or technical assistance with the production of this article" Declarations of interest: Not stated.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated randomization
Allocation concealment (selection bias)	Low risk	"concealed in sealed dark envelopes until intervention was assigned"
Blinding of participants and personnel (performance bias) All outcomes	High risk	Not stated but not possible with study design
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not stated
Incomplete outcome data (attrition bias) All outcomes	Low risk	3 were lost to follow‐up
Selective reporting (reporting bias)	Low risk	None detected
Other bias	Low risk	None detected