Persistence with Oral Contraceptive Pills Versus Metformin in Women with Polycystic Ovary Syndrome

Objective: We studied patient persistence with oral contraceptive pills (OCPs) compared to metformin for treatment of polycystic ovary syndrome (PCOS) in an urban university clinic population. Methods: We conducted a retrospective cohort study of women with PCOS who were treated in our specialty clinic between 2004 and 2006. All women with the diagnosis of PCOS, defined as oligomenorrhea or amenorrhea in conjunction with clinical or biochemical evidence of hyperandrogenism, with exclusion of other causes, were included in the study. We abstracted data on demographic characteristics, medical history, anthropometrical measures, desire for pregnancy, prescribed treatment, and patient report of persistence with treatment at 3, 6, and 12 months. The primary outcome measure was persistence with prescribed treatment. Results: One hundred nineteen subjects were included in the study. Demographic and anthropometrical characteristics were similar between the groups. At 3 months, 57.1% were persistent with OCPs, and 57.8% were persistent with metformin (p = 0.93). At 6 months, the percentages dropped to 38.1% with OCPs and 43.9% with metformin (p = 0.46). At 12 months, only 21.7% continued with OCPs compared to 31.2% with metformin (p = 0.19). Subjects were significantly more likely to be persistent with either OCPs or metformin at 3 months compared to either 6 or 12 months (p < 0.01). Conclusions: Women with PCOS showed similar persistence rates with OCPs compared to metformin. Persistence with either treatment precipitously decreases over time and is modest at 12 months.