About 13% of the nearly one in 10 U.S. adults diagnosed with diabetes did not take their medication as prescribed in 2018 because of the drug's cost, according to a CDC brief released on Wednesday.

Five ways to control the flow of drug expenditures

Background

The cost of diabetes medications such as insulin has increased over past few years. Although the patent on insulin expired about 75 years ago, its price has more than doubled since 2012. A single vial of insulin now has a list price of more than $250—and most patients require two to four vials monthly.

The high prices are due in part to recent improvements that drugmakers have made to the drug, which have yielded new products with new patents. Some of the innovations were substantial: For instance, Eli Lilly's product Humulin was the first bioengineered version of the drug sold in the United States.

But experts say other tweaks to insulin have allowed drugmakers to sell the products at higher prices without resulting in any significant clinical benefits.

Report details

For the report, CDC researchers analyzed data from the 2017–2018 National Health Interview Survey to examine strategies used by adults with diabetes to lower their prescription drug costs.

The researchers found the annual per capita expense for outpatient medication for diabetes patients reached nearly $5,000 in 2017. Further, the researchers found those high costs prompted patients to take measures to lower those costs.

For instance, the researchers found in 2018, 13.2% of adults with diabetes delayed filling a prescription, took less medicine, or skipped a dose because of the cost of their medication.

The researchers found this trend was more common among diabetes patients under age 65 than among seniors ages 65 and older. Specifically, the researchers found 17.9% of adults with diabetes under 65 did not take their medication as prescribed, compared with 7.2% of seniors with diabetes. Among those under age 65, the researchers found who lacked health insurance were more likely not to take their medication as prescribed than those who had private or Medicaid coverage:

Another way diabetes patients sought to lower their prescription drug costs was to ask their physicians for lower-cost medications. The researchers found 24.4% of adults with diabetes asked their providers for a lower-cost medication.

The researchers found patients under age 65 were more likely than seniors to ask their providers for a lower-cost prescription. In particular, they found 26.3% of adults with diabetes under 65 asked their physicians for a lower-cost prescription, compared with 21.9% of seniors.

Among those under age 65, the researchers found patients who lacked health insurance were more likely to have those cost-savings provider conversations than those with private or Medicaid coverage:

Among those ages 65 and older, patients who were dually eligible for Medicare and Medicaid were less likely than others to ask their physician for a lower-cost prescription:

The researchers concluded that "the burden associated with high prescription drug costs remains a public health concern for adults with diagnosed diabetes," despite a recent "shift toward … lower-cost options as the first line of therapy for diabetes management" (Sullivan, The Hill, 8/21; Owens, "Vitals," Axios, 8/21; Wu Tan, Washington Times, 8/21; Busko, Medscape, 8/21).