New research reveals why treatment might appear to fail to control glucose levels in many people with Type 2 diabetes: not taking their medication as prescribed.
“When patients have poor glycemic control, their physicians may assume that there was a medication failure when they were, in fact, not filling their prescriptions,” says Ken Mandl, MD, MPH, of Boston Children’s Hospital, the senior author of a new report in Diabetes Care.
The study raises the question of whether the same might be true for patients with other conditions.
As a first line of defense to control glucose, the American Diabetes Association recommends the use of an anti-hyperglycemic medication called metformin. But when Mandl and colleagues reviewed 52,544 anonymous insurance records from patients with Type 2 diabetes, they found that 22,956 patients had been further prescribed a second-line drug.
“Evidently, less than 10 percent of patients who were prescribed a second-line drug had filled their metformin prescriptions as recommended,” says Mandl, who directs the Computational Health Informatics Program at Boston Children’s.
“For nearly 30 percent of patients, there was no evidence that they had ever taken metformin even though it had been prescribed to them,” Mandl continues.
After accounting for the possibility that some patients were taking low-cost generic versions of metformin, which would not have shown up in the data, the authors estimated that between 8 and 49 percent of individuals had taken metformin according to guidelines prior to starting a second-line therapy.
“Even though pharmacy benefit managers have extensive real-time data about whether and when a patient has filled her prescriptions, this information rarely influences a physician’s practice,” Mandl says. “We need to improve drug adherence monitoring and medication management for diabetes and beyond.”