Vegetti 1998.

Methods	Randomised trial, no method stated. Conducted at First Department of Obstetrics and Gynaecology, University of Milan and Gynaecology Unit, University of Pavia, Varese, Italy Timing: May 1996 to April 1997
Participants	29 participants randomised, 6 cycles/participant. Clomiphene‐resistant PCO women (high LH). Mean age not stated Duration of infertility 2 to 6.5 years, Infertility work‐up not stated, mean BMI not stated
Interventions	Ovarian drilling with diathermy (at least 20 drill holes per ovary), (N = 16) versus Gonadotrophins (pure FSH with low‐dose step‐up protocol) (N = 13) for ovulation induction for 6 cycles Follow‐up for 6 months
Outcomes	Pregnancy rate (per participant), miscarriage rate (per pregnancy), multiple pregnancy rate (per pregnancy)
Notes	Interim results only ‐ further patients will be randomised and a later publication is expected Conflict of interest: not stated
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not stated
Allocation concealment (selection bias)	Unclear risk	Unclear
Blinding of participants and personnel (performance bias) All outcomes	High risk	No blinding of participants or study personnel
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No details provided
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Not stated
Selective reporting (reporting bias)	Unclear risk	We could not retrieve the original protocol
Other bias	Unclear risk	Interim details only