Metformin rarely prescribed for prediabetes, study finds

Very few patients with prediabetes are prescribed metformin, according to a recent study of working-age adults.


Very few patients with prediabetes are prescribed metformin, according to a recent study of working-age adults.

The retrospective cohort study used a health plan database to study 17,352 adults age 19 to 58 who had been diagnosed with prediabetes and were followed from 2010 through 2012. Researchers found that only 3.7% of the patients were prescribed metformin. Certain subgroups were more likely to receive the drug—prescriptions were almost twice as high among women and obese patients as the others, and patients with 2 or more comorbidities were 1.5 times as likely to take metformin.

The results show “underuse of a highly effective prevention strategy,” the authors concluded. Barriers to use of metformin for prediabetes may include lack of knowledge about the supporting evidence, the absence of FDA approval of the drug for this indication, and reluctance on the part of patients and/or clinicians to “medicalize” prediabetes, they speculated. The authors also recognized that their data was claims-based and thus the analysis would not have captured a prescription for metformin if a patient either paid out of pocket or chose not to fill the prescription. They noted that the patient population they studied was broader than the one recommended for metformin treatment under American Diabetes Association guidelines but that even among the guideline-indicated subset of patients, only 7.8% were receiving metformin.

The authors called for tools, incentives, or public awareness campaigns to encourage informed decision making on prediabetes treatment and to bring evidence on metformin into real-world practice. The study was published in the April 21 Annals of Internal Medicine.