State-level insulin cost caps are ineffective in increasing insulin use among people with diabetes

In a first-of-its-kind study, a group of researchers led by the University of Colorado Anschutz Medical Campus evaluated the impact of state-level insulin copay caps across states, payers, and over time. The team found that state-level insulin copay caps do not significantly increase insulin bills for people with type 1 diabetes or those who use insulin to manage their type 2 diabetes. The findings could inform policy development aimed at better providing capped insulin to patients who struggle to afford insulin.

About a quarter of patients who use insulin to manage their diabetes report underusing it because of cost, a problem that state-mandated cap relaxations are intended to alleviate. Health issuesevaluated the effectiveness of these caps in providing insulin access to patients who rely on insulin to manage their diabetes.

“We found that these caps did not lead to meaningful increases in insulin use. This is in part because these caps focus on privately insured patients with state-level oversight. The vast majority of patients subject to the caps were already paying out-of-pocket amounts below the caps prior to their implementation.”

Kelly E. Anderson, PhD, MPH, assistant professor at the University of Colorado Skaggs School of Pharmacy and lead author of the study.

Using difference-in-differences methods, the researchers assessed out-of-pocket spending and insulin use among more than 33,000 privately insured people with type 1 diabetes or insulin-using type 2 diabetes in both states with and without copayment caps. Results showed that not only did these caps not increase insulin use over time, but even the most generous caps ($25-35) were not used effectively, in part because most private enrollees paid copayments below the mandated caps.

Anderson says these findings could help shape more effective policies. “As the current administration proposes expanding private out-of-market price caps nationwide, it would be beneficial to better assess who is struggling most to afford insulin,” Anderson says. “The administration has capped insulin copayments for Medicare beneficiaries. Providing additional caps for patients who struggle to afford insulin, such as those who are uninsured or have high-deductible health plans, may be more beneficial than a national cap for all private enrollees.”

“Furthermore, expanding cap policies to include additional classes of medications that are often more expensive, such as GLP-1 and SGLT-2, has the potential to make them affordable for more patients. While the majority of people with type 1 diabetes use insulin to manage their blood sugar levels, only 20-30 percent of people with type 2 diabetes do so. Considering other management tools could significantly increase the number of patients covered by these policies.”