From 2002 to 2013, the mean price of insulin increased 197 percent from $4.34 per mL to $12.92 per mL, according to a survey of more than 27,000 people treated for diabetes.
The mean price of oral medications such as dipeptidyl peptidase-4 inhibitors increased by 34 percent from $6.67 per tablet in 2006 to $8.92 per tablet in 2013, while the mean price of metformin decreased by 93 percent from $1.24 per tablet in 2002 to $0.31 per tablet in 2013.
Lead researcher Xinyang Hua, MSc, of the University of Melbourne in Australia, and colleagues published their findings online in JAMA on April 5.
“We were unable to separate out generics from branded medications; however, unlike oral therapies, the mean price of insulin is unlikely to decline as a result of generic competition because of the stringent regulations and substantial costs of bringing biosimilar insulins to market,” they wrote.
The researchers analyzed data from the Medical Expenditure Panel Survey (MEPS), which includes noninstutionalized residents. The mean age of the 27,878 participants was 60.4 years old, and 44.4 percent of participants were men.
The prevalence of treated diabetes increased from 5.2 percent in 2002-2004 to 6.2 percent in 2005-2007 to 7.1 percent in 2008-2010 to 7.7 percent in 2011-2013. Meanwhile, the quantity of insulin per participant increased from 171 mL in 2002-2004 to 206 mL in 2011-2013, while the estimated spending for insulin per patient increased from $231.48 in 2002 to $736.09 in 2013.
In 2013, the estimated expenditure per patient was $507.89 for analog insulin, $228.20 for human insulin and $502.57 for all other antihyperglycemic medications.
The researchers cited a few limitations of the study, including changes in the MEPS beginning in 2007 that may have increased reported drug expenditures by 10 percent. They also did not include the cost of insulin delivery systems except for prefilled pens in their estimates of expenditures and prices.
“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 wrote.