$35 Cap on Insulin Could Boost Medication Adherence, Satisfaction

January 17, 2023 - The Inflation Reduction Act’s $35 cap on insulin cost-sharing is poised to improve patient satisfaction, medication adherence, and prescription affordability, according to a research note published in JAMA Network Open.

However, the insulin cap proposal should be reexamined to account for health equity, the researchers said. Moreover, further considerations to incentivize the use of lower-cost biosimilars will be essential to tamping down on Medicare costs.

The high cost of insulin is a well-documented care access barrier, with medication adherence suffering because patients can’t afford the cost of their insulin prescriptions. In 2019, the CDC reported that 13 percent of individuals with diabetes did not take their insulin as prescribed because of the high cost of the drug ($250 at the time of the report, according to GoodRx figures).

The Inflation Reduction Act (IRA) of 2022 seeks to remedy that issue by capping out-of-pocket costs for insulin at $35 for individuals enrolled in Medicare. The researchers looked at Medicare figures from 2019 to determine that around 1.4 million individuals would benefit from the cap, as they had insulin costs exceeding $35 each month.

The IRA’s insulin cap proposal is coming just in time, the researchers added, as the proportion of individuals saddled with high insulin costs continues to grow. In 2006, around a fifth of Medicare Part D beneficiaries met the $35 insulin cost threshold; that figure grew to 44.6 percent in 2013 and remained steady through 2019.

Moreover, the insulin cap stands poised to address healthcare’s medication adherence problem. The team looked at the link between high insulin costs (defined as costs exceeding $35 monthly) and medication adherence, finding that high costs indeed stymy adherence. All said, having high insulin costs was linked with a 61 percent decrease in medication adherence.

Said otherwise, when people do not have an insulin cap, they are more likely to have poor medication adherence, likely because they cannot afford their medication.

The researchers also found a link between the insulin cap and patient satisfaction and overall prescription affordability.

Folks with high insulin costs saw an 83 percent lower likelihood for prescription satisfaction and a 50 percent lower likelihood for prescription affordability.

That all said, there is serious room for improvement in the insulin cap program, the researchers said. For example, women, younger Medicare enrollees, and racial and ethnic minorities are less likely to be eligible for the insulin cap, they found.

“This study warrants more equitable eligibility criteria for the IRA insulin cap in the future,” the researchers recommended.

Additionally, the researchers acknowledged the insulin cap’s potential to balloon overall Medicare insulin expenditures. The program offers little incentive for cap beneficiaries to select lower-cost insulins, like biosimilars.

“This lack of incentive will likely lead to higher total insulin expenditures, from a societal perspective,” the research team wrote.

“Policy makers may consider strategies (eg, encouraging use of biosimilar insulin) to control future insulin costs,” they concluded. “Attention should also be paid to expensive medications other than insulin, because patients with diabetes are increasingly being treated with these drugs.”