Moro 2013.

Study characteristics
Methods	Randomised controlled trial Location of the trial: quote: "Roma, Italy" Method of randomisation: quote: "computer‐generated randomization list" Method of allocation concealment: quote: "staff member independent of the study controlled the randomization" Source of funding: None
Participants	Inclusion criteria: the PCOS was diagnosed on the basis of the presence of 2 of the 3 following criteria: oligomenorrhoea, biochemical/clinical hyperandrogenism, and polycystic ovary (PCO) on ultrasound, according to the Rotterdam criteria. Exclusion criteria: the exclusion criteria were inflammatory/autoimmune disease, cancer, treatment with clomiphene citrate, OC, antiandrogens, anorexic, or insulin‐sensitizing drugs during the last 6 months prior to our evaluation, DM2, hypertension, major surgery in the last 3 months, or other hormonal dysfunctions (hypothalamic–pituitary, thyroidal, or adrenal causes). Patients with normoinsulinaemic PCOS, with insulinaemic area under the curve (AUCi) < 7000, were also excluded. Number of women randomised: 93 MET + OCP: 31 MET: 31 OCP: 31 Number of women analysed: 76 MET + OCP: 25 MET: 25 OCP: 26 Number of withdrawal and reasons: MET + OCP: Incomplete data: 2 /6.5% GI adverse events: 2/ 6.5% Voluntary drop out: 1/ 3.2% MET: Incomplete data: 3/9.7% GI adverse events: 2/ 6.5% Voluntary drop out: 1/ 3.2% OCP: Incomplete data: 5/16% Voluntary drop out: 1/ 3.2% Summary characteristics: PCOS Non normoinsulinaemic Age (years): MET + OCP mean (+SD): 25 (4) MET mean (+SD): 25 (5) OCP mean (+SD): 26 (3) BMI (kg/m2): MET + OCP median (range): 26.5 (21.3 to 30) MET median (range): 25.1 (21.9 to 28.3) OCP median (range): 23.7 (20.8 to 28.6)
Interventions	OCP (Ethinyl Estradiol 30 mcg drospirenone 3 mg) + MET 500 mg three times a day OCP (Ethinyl Estradiol 30 mcg drospirenone 3 mg) MET 500 mg three times/day Duration: 6 months Co‐intervention(s): induced menstrual cycle with medroxyprogesterone acetate 10m g/day for 7 days
Outcomes	Primary outcomes: Adverse events: severe (requiring stopping of medication) and minor Secondary outcomes: BMI (kg/m2) Serum total testosterone (nmol/L) Free androgen index (FAI) (%) Fasting total cholesterol (mmol/L) Fasting HDL cholesterol (mmol/L) Fasting LDL cholesterol (mmol/L) Fasting triglycerides (mmol/L)
Subjective outcomes	None
Objective outcomes	(a) Clinical parameters 1. Adverse events: severe (requiring stopping of medication) and minor 2. BMI (kg/m2) (b) Hormonal parameters 1. Serum total testosterone (nmol/L) (c) Metabolic parameters 1. Free androgen index (FAI) (%) 2. Fasting total cholesterol (mmol/L) 3. Fasting HDL cholesterol (mmol/L) 4. Fasting LDL cholesterol (mmol/L) 5. Fasting triglycerides (mmol/L)
Notes	Power calculation: unclear
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "A total of 93 consecutive eligible patients, who accepted to participate to the study, were randomly assigned to 1 of the 3 treatment groups, after age and BMI matching by giving them a code number from a computer‐generated randomization list, in order of enrolment."
Allocation concealment (selection bias)	Low risk	Quote: "Staff member independent of the study controlled the randomization."
Blinding of participants and personnel (performance bias) All outcomes	High risk	Quote: "Both the patients and the gynaecologists were informed of the assigned treatment.”
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Insufficient information available to permit a judgement of ‘low risk’ or ‘high risk’. Blinding not stated.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Quote: "Incomplete data, voluntary drop out" unclear reason for withdrawal. Insufficient reporting of attrition/exclusions to permit a judgement of 'low risk' or 'high risk'.
Selective reporting (reporting bias)	Low risk	The study protocol is not available but it is clear that the published reports include all expected outcomes, including those that were prespecified.
Other bias	Low risk	The study appears to be free of other sources of bias.