A recent study indicated that using sulfonylurea after metformin for the treatment of type 2 diabetes has as much of an effect as using other conventional treatments, but costs far less. The study was published online on the 26th of February in the journal Diabetes Care. The study was led by Yuanhui Zhang, a PhD candidate at North Carolina State University, Raleigh.
There are currently 11 classes of approved glucose-lowering medication, and metformin has a long-standing evidence for efficacy and for safety at lower cost and is chosen as the primary first-line treatment for type 2 diabetes. When the treatment with metformin does not show enough effects, another agent should be chosen. However, there is no consensus or sufficient evidence supporting the use of one second-line agent over another.
“In light of an incomplete understanding of the pros and cons of second-line medications and the high cost associated with newer medications, the decision to use newer medications should be weighed against the additional cost burden to patients and/or the health system,” said Brian Denton, PhD, of the University of Michigan, Ann Arbor, told Medscape Medical News.
In the study, researchers analyzed the data of 37,501 patients with type 2 diabetes who were over 40 and diagnosed with the disease between 1995 and 2010. Outcomes were compared among patients received sulfonylurea, DPP-4 inhibitor, GLP-1 agonist, or insulin for the intensification of metformin mono therapy. The researchers evaluated their life-years (LYs), quality-adjusted life-years (QALYs), mean time to insulin dependence, and expected medication cost per QALY from diagnosis to first diabetes-related complications (ischemic heart disease, myocardial infarction, congestive heart failure, stroke, blindness, renal failure, amputation) or death.
As a result, all regimens resulted in similar LYs and QALYs. However, sulfonylurea treatment incurred significantly lower cost per QALY and resulted in the longest time to insulin dependence (about 1 year vs 0.53–0.62 years for the other 2 regimens). Average medication costs per month were $81.75 for metformin, $54.85 for sulfonylurea, $232.84 for DPP-4 inhibitor, $325.97 for GLP-1 agonist, and $245.70 for insulin.
However, Alan J. Garber, MD, PhD, of Baylor College of Medicine, Houston, Texas, noted to Medscape Medical News that “the use of retrospective data means that the study is subject to both ascertainment and physician-choice bias,” and that “Patients value things differently. If you had a hypoglycemic episode and you don’t like that, you’re willing to pay a lot more of your discretionary income to avoid having another one,” which undoubtedly affected the outcome of the study.
Expected medication costs per QALY ranged from a low of $2600/QALY for metformin/sulfonylurea in women to a high of $2891/QALY for metformin/GLP-1 agonist in men. Compared with the metformin/sulfonylurea regimen, which was the least expensive, additional cost per QALY incurred with the other second-line agents ranged from $141/QALY for DPP-4 inhibitor in women to $216/QALY for GLP-1 agonist in men.
“The differences in cost per patient among the 4 treatment regimens were substantial and thus of potential importance to patients as well as healthcare providers and payers,” commented the authors.