Comparison 8. Adult ‐ OCP versus Metformin combined with OCP (Hormonal parameters).

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
8.1 Serum total testosterone (nmol/L)	12	715	Mean Difference (IV, Fixed, 95% CI)	0.08 [0.01, 0.16]
8.1.1 BMI ≤ 25 kg/m2	6	327	Mean Difference (IV, Fixed, 95% CI)	0.08 [‐0.01, 0.17]
8.1.2 BMI > 25 kg/m2 < 30 kg/m2	6	369	Mean Difference (IV, Fixed, 95% CI)	0.10 [‐0.04, 0.24]
8.1.3 BMI ≥ 30 kg/m2	1	19	Mean Difference (IV, Fixed, 95% CI)	0.90 [‐4.23, 6.03]
8.2 Free androgen index (FAI) (%)	7	482	Mean Difference (IV, Fixed, 95% CI)	0.51 [0.30, 0.71]
8.2.1 BMI ≤ 25 kg/m2	3	215	Mean Difference (IV, Fixed, 95% CI)	0.47 [‐0.12, 1.06]
8.2.2 BMI > 25 kg/m2 < 30 kg/m2	4	267	Mean Difference (IV, Fixed, 95% CI)	0.51 [0.29, 0.73]