Al‐Zubeidi 2015.

Study characteristics
Methods	Randomised controlled trial Location of the trial: quote: San Diego, USA Method of randomisation: quote: “Each patient was randomly assigned to group 1 or group 2 using concealed assignments from random numbers that were computer generated.” Method of allocation concealment: not stated. Source of funding: not stated.
Participants	Inclusion criteria: inclusion of patients in the study was based on the NIH criteria for the diagnoses of PCOS in this age group, which includes irregular menses or amenorrhoea and elevated free or total testosterone. Irregular menses or amenorrhoea was defined as less than or equal to eight menses per year. In addition, other causes of hyperandrogenism were excluded including: adrenal tumours, late congenital adrenal hyperplasia, and prolactinomas. Patients were only enrolled 2 years post‐menarche given the potential for menstrual irregularity in normal maturation post‐menarche. Exclusion criteria: exclusion criteria included: current treatment or treatment within the last 3 months with metformin or OCP and personal or family history of blood clotting disorders, breast cancer, stroke, severe migraines with aura, elevated BP, defined as either systolic and/or diastolic BP ≥ 95th percentile measured upon three or more occasions, and smoking defined by more than one pack per day for the past 6 months. Number of women randomised: 34 MET: 16 OCP: 18 Number of women analysed: 22 MET: 10 OCP: 12 Number of withdrawal and reasons: MET: no shows and unreachable: 5 /31.2% No insurance: 1/ 6.2% OCP: no shows: 4/ 22.2% No insurance: 1/ 5.6% Decline treatment: 1/ 5.6% Summary characteristics: PCOS, adolescent 12 to 18 years, 68% Hispanic Age (years): MET: range: 14 to 18 OCP: range: 15 to 17 BMI (kg/m2): MET mean (+ SD): 33.7 (6) OCP mean ( + SD): 33.4 (9)
Interventions	Treatment: MET 1g twice a day gradual increase maximum dose was reached over 3‐week period Control: OCP (Ethinyl Estradiol 30mcg Noresthisterone 1mg) Duration: 6 months Co‐intervention(s): routine counselling about diet and exercise was done in clinic, but no specific exercise or diet prescription was offered.
Outcomes	Primary outcomes: Hirsutism score Adverse events: severe (requiring stopping of medication) and minorSecondary outcomes: Menstrual cyclicity, initiation of menses or significant shortening of cycles BMI (kg/m2) Serum total testosterone (nmol/L) Fasting insulin (mIU/L) Fasting HDL cholesterol (mmol/L) Fasting triglycerides (mmol/L)
Subjective outcomes	(a) Clinical parameters 1. Hirsutism score
Objective outcomes	(a) Clinical parameters 1. Adverse events: severe (requiring stopping of medication) and minor 2. Menstrual cyclicity, initiation of menses or significant shortening of cycles 3. BMI ((kg/m2) (b) Hormonal parameters 1. Serum total testosterone (nmol/L) (c) Metabolic parameters 1. Fasting insulin (mIU/L) 2. Fasting HDL cholesterol (mmol/L) 3. Fasting triglycerides (mmol/L)
Notes	Power calculation: yes, a priori, on FT and BMI (secondary outcomes)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: “Each patient was randomly assigned to group 1 or group 2 using concealed assignments from random numbers that were computer generated.”
Allocation concealment (selection bias)	Unclear risk	Method of allocation concealment not stated. Insufficient information available to permit a judgement of ‘low risk’ and ‘high risk’.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Insufficient information available to permit a judgement of ‘low risk’ or ‘high risk’. Blinding not stated.
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: "No show, unreachable" unclear reasons for withdrawal and could be related to the intervention. Insufficient report of attrition/exclusions to permit a judgement of ‘low risk’ or ‘high risk’.
Selective reporting (reporting bias)	High risk	Measurement of hirsutism and improvement in menstrual pattern described in methods but not reported in the result or reported without giving the number of patient with improvement in menstrual pattern. HDL cholesterol, SD not reported for OCP group therefore could not be included in the meta‐analysis. Hirsutism is one of our primary outcomes, not all of the study's prespecified primary outcomes have been reported.
Other bias	Low risk	The study appears to be free of other sources of bias.