Cost Analysis: Insulin & Other Antihyperglycemics

The price of insulin increased dramatically from 2002 to 2013 in the United States as compared with oral antihyperglycemics, according to a new study.¹

“Based on a nationally representative survey, the mean price of insulin increased from $4.34/mL in 2002 to $12.92 in 2013. The estimated expenditure per patient for insulin in the United States in 2013 was greater than all other antihyperglycemic medications combined,” stated the authors, led by senior author Philip Clarke, PhD, of the University of Melbourne in Australia.

They noted that recent studies demonstrate widespread substitution of analog for human insulin and rising out-of-pocket costs in privately insured people with type 2 diabetes mellitus in the United States. “Medicaid reimbursements have increased for both human insulin and more costly analog insulins,” they stated, noting that theirs is the first report of trends in expenditures for different classes of antihyperglycemic medications that simultaneously consider changes in use and price.

The authors conducted a pharmacoeconomic study using Medical Expenditure Panel Survey (MEPS) data to compare trends in expenditure and price of antihyperglycemic medications in the United States from 2002 through 2013.

They first described the prevalence of treated patients with diabetes, their characteristics, and use of antihyperglycemic medications. Then they estimated inflation-adjusted expenditures per patient for insulin, combining both human and analog, compared with other classes of antihyperglycemics. They evaluated individual and prescription-level data from 27,878 people treated for diabetes, mean age 60 years.

Their results indicated that the prevalence of treated diabetes increased to 7.7% in 2011–2013 from 5.2% in 2002–2004. The estimated spending for insulin per patient increased considerably to $736.09 in 2013 from $231.48 in 2002. The average price/mL of insulin rose by 197% between 2002 and 2013.

In contrast, the mean price of dipeptidyl peptidase-4 inhibitors increased by only 34%, from $6.67 per tablet in 2006 to $8.92 in 2013. And the average price of metformin decreased by 93% from $1.24 per tablet in 2002 to $0.31 per tablet in 2013.

In 2013, the cost of analog insulin was about $507.89 per patient and the cost of human insulin was about $228.20 per patient.

Increased treatment intensity may have contributed to the rising costs, they suggested. The amount of insulin used also increased from 171 mL in 2002–2004 to 206 mL in 2011–2013. Also, a change in editing rules for MEPS-prescribed medications could have overestimated drug expenditures by 10%.

“Significant changes in mean price of insulin, relative to comparator therapies, suggest a need to reassess the effectiveness and cost-effectiveness of alternative antihyperglycemic therapies,” they stated.

Last year, a study² found that Medicaid payments for all types of insulin had risen sharply between 1991 and 2014. The authors found “a near-exponential upward trend in Medicaid payments” for a wide variety of insulin products regardless of formulation, duration of action, and whether the product was patented. They concluded that “although reimbursements for newer, patent-protected insulin analogs increased at a faster rate than reimbursements for older insulins, payments increased for all products.”

References:

1. Hua X, et al. Expenditures and prices of antihyperglycemic medications in the United States: 2002-2013.  JAMA. 2016;315(13):1400-1402.

2. Luo J, et al. Trends in Medicaid reimbursements for insulin from 1991 through 2014. JAMA Intern Med. 2015;175(10):1681-1686.