Allen 2005.

Study characteristics
Methods	Randomised controlled trial Location of the trial: quote: Massachussets, USA Method of randomisation: quote: "Random numbers table" Method of allocation concealment: not stated Source of funding: not stated
Participants	Inclusion criteria: hyperandrogenaemia (total T > 60 ng/dL and free T > 1.1 pg/mL), no evidence of androgen secreting tumour, oligomenorrhoea (< 6 menses in the previous 6 months) and obesity (> 95th percentile BMI for age), hyperinsulinaemic (fasting insulin > 20 µU/mL) but not diabetic (fasting glucose < 126 mg/dL). PCOS diagnosis consistent with NIH. Exclusion criteria: reported current or past sexual activity, OCP use within previous 6 months, positive urine pregnancy test (performed on all participants at baseline), abnormal BUN, Cr, AST or positive personal or family history of thrombosis, primary adrenal source of androgeneses. Number of women randomised: 35 MET: 18 OCP: 17 Number of women analysed: 31 MET: 16 OCP: 15 Number of withdrawal and reasons: MET: 2/ 11% OCP: 2/ 12% All unreachable or refused to come to further visits. No breakdown by MET versus OCP. Summary characteristics: PCOS, 12 to 21 years, obese, hyperinsulinaemic, oligoamenorrhoeic and hyperandrogenaemia Age (years): MET Mean (range): 15.4 years (13.1 to 18.4) OCP Mean (range): 15.3 years (12.5 to 21) BMI (kg/m2): MET (mean ± SEM): 37.3 (1.3) OCP (mean ± SEM): 40.1 (2.1)
Interventions	Treatment: MET 500 mg twice a day 2 weeks and dose increased to 1 g twice a day if tolerated Control: OCP (Ethinyl Estradiol 35mcg norgestimate 0.25 mg) Duration: 6 months Co‐intervention(s): none
Outcomes	Primary outcomes: Hirsutism score Secondary outcomes: Menstrual cyclicity, initiation of menses or significant shortening of cycles Acne score Body weight (kg) BMI (kg/m2) Serum total testosterone (ng/dL) Fasting insulin (µU/L) Fasting glucose (mmol/L) Fasting total cholesterol (mg/dL) Fasting HDL cholesterol (mg/dL) Fasting LDL cholesterol (mg/dL) Fasting triglycerides (mg/dL)
Subjective outcomes	(a) Clinical parameters 1. Hirsutism score 2. Acne score
Objective outcomes	(a) Clinical parameters 1. Menstrual cyclicity, initiation of menses or significant shortening of cycles 2. Body weight (kg) and/or BMI (kg/m2) (b) Hormonal parameters 1. Serum total testosterone (ng/dL) (c) Metabolic parameters 1. Fasting insulin (µU/L) 2. Fasting glucose (mmol/L) 3. Fasting total cholesterol (mg/dL) 4. Fasting HDL cholesterol (mg/dL) 5. Fasting LDL cholesterol (mg/dL) 6. Fasting triglycerides (mg/dL)
Notes	Authors contacted about: Ferriman‐Gallwey score, menstrual rate and acne score because expressed with graph. Authors were also contacted to ask about free testosterone because calculated in the methods as total testosterone/SHBG. Power calculation: yes, a priori on free testosterone
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Random numbers table".
Allocation concealment (selection bias)	Unclear risk	Method of allocation concealment not stated. Insufficient information available to permit judgement of ‘low risk’ or ‘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: "All unreachable or refused to come to further visits" unclear reason for withdrawal could be related to intervention. Insufficient reporting of attrition/exclusions to permit a judgement of 'low risk' or 'high risk.
Selective reporting (reporting bias)	High risk	From results section of paper, all of the studies pre‐specified (primary and secondary) outcomes that are of interest in the review have been reported in the pre‐specified way with the exception of blood pressure, Ferriman‐Gallwey score, acne score, menstrual improvement. These 3 last outcomes are presented with graphs. One or more outcomes of interest in the review have been reported incompletely so that they cannot be entered in a meta‐analysis.
Other bias	Low risk	The study appears to be free of other sources of bias.