Meyer 2007.

Study characteristics
Methods	Randomised controlled trial Location of the trial: quote: "Melbourne, Australia"Method of randomisation: quote: "computer‐generated random numbers"Method of allocation concealment: not statedSource of funding: pharmaceutical, quote: "This work was an investigator‐initiated trial funded by a competitive CVL grant sponsored by Pfizer Australia and through internal department funds. Pfizer Australia provided the aldactone, and Douglas Pharmaceuticals Australia provided the metformin. H.J.T is an National Health and MedicalResearch Council and National Heart Foundation Fellow. C.M. is an National Health and Medical Research Council PhD Scholar."
Participants	Inclusion criteria: PCOS diagnosis was based on perimenarchal onset of irregular cycles ( < 21 days or > 35 days) and clinical manifestations of hyperandrogenism (hirsutism or acne) or biochemical hyperandrogenism with elevation of at least one circulating ovarian androgen (according to 1990 National Institutes of Health criteria). Exclusion criteria: secondary causes of amenorrhoea and hyperandrogenism were excluded with clinical screening and early follicular 17‐hydroxyprogesterone levels. Diabetes was excluded on OGTTs. Pregnancy tests were negative before enrolment. Number of women randomised: 72: MET : 37 OCP: 35 Number of women analysed: 67 MET: 36 OCP: 31 Number of withdrawal and reasons: MET: Personal reason: 1/ 2.7% OCP: Personal reason: 3/ 9.7% Swinging mood: 1/ 3.2% Summary characteristics: PCOS, Overweight BMI > 27 kg/m2, Mean age 31 years. BMI (kg/m2): MET mean: BMI (kg/m2): 36.3 OCP mean: BMI (kg/m2): 36.5
Interventions	Treatment: MET (1000 mg twice a day 500 mg twice a day 4 weeks)Control: OCP (Ethinyl estradiol 35mcg Cyproterone acetate 2 mg)Duration: 6 monthsCo‐intervention(s): exercise and diet
Outcomes	Primary outcomes: Hirsutisme score Adverse events: severe (requiring stopping of medication) and minor Secondary outcomes: Menstrual cyclicity, initiation of menses or significant shortening of cycles Body weight (kg) BMI (kg/m2) Blood pressure (systolic) (mm Hg) Blood pressure (diastolic) (mm Hg) Serum total testosterone (nmol/L) Free androgen index (FAI) (%) Fasting insulin (mIU/L) Fasting total cholesterol (mmol/L) Fasting HDL cholesterol (mmol/L) Fasting LDL cholesterol (mmol/L) Fasting triglycerides (mmol/L)
Subjective outcomes	(a) Clinical parameters 1. Hirsutism score
Objective outcomes	(a) Clinical parameters 1. Menstrual cyclicity, initiation of menses or significant shortening of cycles 2. BMI (kg/m2) 3. Blood pressure (systolic) (mm Hg) 4. Adverse events: severe (requiring stopping of medication) and minor (b) Hormonal parameters 1. Serum total testosterone (nmol/L) 2. Free androgen index (FAI) (%) (c) Metabolic parameters 1. Fasting insulin (mIU/L) 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: yes, a priori, on insulin sensitivity (secondary outcome)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: “At randomization, 110 subjects were allocated to one of three groups based on computer‐generated random numbers”.
Allocation concealment (selection bias)	Unclear risk	Method of allocation concealment not stated. Insufficient information available to permit a judgement of ‘low risk’ or ‘high risk’.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Quote: “This was an open‐label study”.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "End point data collection was completed by the research nurse, who was blinded to treatment allocation”.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Quote: "Personnal reason" unclear reason of 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 pre‐specified.
Other bias	High risk	Population not comparable regarding androgenism status. Quote: "Groups were well matched at baseline except for Ferriman‐Gallwey score (8.8 + 0.8 vs. 6.7 + 0.7, P< 0.05) and testosterone levels (2.5 +0.1vs. 2.1 +0.1) in the metformin and high ‐dose OCP" Baseline imbalance.