State caps on insulin costs for commercially insured didn't increase insulin use
Limits on out-of-pocket costs did lower patients' insulin expenses, but the effect was mostly limited to those with health savings accounts, a pre-post comparison among U.S. states found.
Caps on out-of-pocket costs for insulin reduced costs for patients with health savings accounts but didn't increase overall use of insulin, a study found.
The pre-post study looked at insulin costs for commercially insured patients in eight states that implemented caps of $25 to $30, $50, or $100 in January 2021 versus in 17 control states that did not implement caps. All studied patients were insulin users younger than 65 years. Results were published by Annals of Internal Medicine on March 26.
Overall, state insulin caps were not associated with any significant change in insulin use (relative change in fills per month, 1.8%; 95% CI, −3.2% to 6.9%). The caps were associated with a 17.4% decrease (95% CI, −23.9% to −10.9%) in out-of-pocket costs for insulin. That change was driven by the proportion of studied patients who were enrolled in health savings accounts; costs did not drop significantly for the rest of the population. Lower price caps ($25 to $30) were associated with a larger savings (40.0%; 95% CI, −62.5% to −17.6%).
The study authors noted that their findings differed from a recent study of Medicare's $35 insulin cap, which found that it increased insulin use among Medicare beneficiaries. They noted that "commercially insured persons might have more resources to afford insulin and thus might be less affected by [out-of-pocket] OOP cap policies." In fact, the current study found that higher-income insulin users saved more thanks to the caps than lower-income users did, suggesting that future efforts may need to more specifically target lower-income patients, the study authors said. They also called for more work on solutions that actually lower overall insulin prices.
"Our findings suggest that the proposed national $35 insulin cap for commercially insured persons would reduce OOP costs by a large degree for HSA plan members but have little effect on OOP costs for nonaccount plan members, who comprise the vast majority of the commercial market," the authors wrote. "Improving insulin underuse is probably more complex and challenging. Approaches would likely need to be multifaceted, involving publicity about insulin OOP cost reductions, identification of barriers to appropriate insulin use, and enhanced identification of affected patients."