Medicare Beneficiaries With High Out-of-Pocket Costs May Reduce Insulin Adherence

By Carolyn Crist

February 19, 2021

NEW YORK (Reuters Health) - Patients with diabetes who face high out-of-pocket costs under Medicare Part D may buy or use less insulin than they're prescribed, according to a new study.

New policy changes could reduce out-of-pocket costs and help patients to afford their insulin, the research team suggests in JAMA Network Open.

"This is an essential medicine, and it is important to understand how this increased financial burden impacts patient adherence and health," said lead author Dr. Erin Trish of the University of Southern California Schaeffer Center for Health Policy and Economics in Los Angeles.

More than 3 million Medicare beneficiaries take insulin, she told Reuters Health by email, and out-of-pocket spending on insulin under Medicare Part D has quadrupled during the past decade. Although some Part D plans will limit cost-sharing on insulin in 2021, it's a "patch" on a larger problem, she said.

"The time has come for policymakers to fix Part D so it works better for everyone," she said.

Dr. Trish and colleagues calculated out-of-pocket spending and insulin adherence from 2018 Medicare Part D claims before and after reaching the "coverage gap," where beneficiaries face increased cost-sharing. The team looked at two groups - beneficiaries on individual plans whose cost-sharing can vary widely across coverage phases and those enrolled through an employer group-waiver plan where cost-sharing is low and constant across coverage phases.

The research team found that, among the more than 303,000 individual-plan enrollees, the mean cost-sharing for insulin was about $50 per month in the initial coverage phase, which jumped to about $117 per month in the coverage gap. The 171,313 employer-plan enrollees paid about $32 across all benefit phases.

"We were surprised by how much more patients have to pay for insulin when they reach the Part D doughnut hole," Dr. Trish said. "Policymakers have worked toward closing the doughnut hole, but this shows that their efforts have come up short."

In addition, individual-plan enrollees who ended the year in the coverage gap reduced their use of insulin by 5.4 percentage points compared to their use in the initial coverage phase, shifting from 67.5% to 62.1%.

Those in the employer plan who ended the year in the coverage gap increased their use by 2.8 percentage points, shifting from 70.1% to 72.9%. About half of the Medicare Part D beneficiaries ended the year in the coverage gap.

"Insulin is a perfect example of what is wrong with our prescription-drug supply chain. Rebates on insulin are huge, often 50% to 60% of the price, but patients don't benefit from these discounts at the pharmacy counter," Dr. Trish said. "Instead, they pay high out-of-pocket prices and sometimes forego needed medicine. We need to overhaul the system to get rid of these problematic incentives and make it work for patients."

In 2021, some Part D plans are limiting cost-sharing on insulin to $35 per month under the Senior Savings Model. This shift could improve adherence and help patients who opt for these plans, she said, though it's not an overall solution.

"Though this program has yet to be evaluated, this $35 flat copayment program is likely to be effective at improving adherence to insulin," said Dr. Stacie Dusetzina of the Vanderbilt University School of Medicine in Nashville, Tennessee. Dr. Dusetzina, who wasn't involved in this study, has researched Medicare Part D and insurance affordability.

"However, there could be some differences between people who are in Part D alone versus those with employer benefits," she told Reuters Health by email. "It will still be important to evaluate the $35 copayment test to be sure."

SOURCE: JAMA Network Open, online January 26, 2021.