Metformin Prescription Rates for Patients with Prediabetes

Prediabetes is a serious public health concern, with 34.5% of US adults meeting the criteria for prediabetes. The American Diabetes Association has highlighted metformin therapy as a consideration for individuals with BMI ≥ 35 kg/m², those aged < 60 years, and women with a history of gestational diabetes. We examined metformin prescription rates among a national sample of commercially insured, higher risk patients with prediabetes.

We gathered 2012 to 2018 demographic, laboratory, and prescription data for 53,551 patients with prediabetes from the IBM MarketScan research database. Our primary outcome was metformin prescription rates 1 or 3 years after a laboratory confirmation of prediabetes among patients who have a BMI ≥ 35 kg/m² or are aged < 60 years.

Overall, 2.4% (n = 1,124) of patients received a metformin prescription within 1 year of a laboratory confirmed prediabetes result, including 2.4% of patients aged < 60 years and 10.4% of those with BMI ≥ 35 kg/m². By a 3 year follow-up, 4.1% (n = 1901) received a metformin prescription, including 3.9% of patients aged < 60 years and 14.0% with BMI ≥ 35 kg/m². Patients who developed type 2 diabetes within the 1 (n = 2,769) or 3 year (n = 7,268) follow-up periods were excluded from analysis.

Few prediabetes patients who were either obese or aged < 60 years received a metformin prescription between 2012 and 2018. Prescription rates increased slightly between 1 and 3 years after a prediabetes diagnosis, so strategies to support timely intervention among higher risk patients with prediabetes are critically needed.