State Out-Of-Pocket Caps On Insulin Costs: No Significant Increase In Claims Or Utilization
Kelly E. Anderson, Nathorn Chaiyakunapruk, Eric J. Gutierrez, Howard Weston Schmutz, Michael R. Rose, Diana Brixner, R. Brett McQueen
Abstract
Nearly all patients with type 1 diabetes and 20-30 percent of patients with type 2 diabetes use insulin to manage glycemic control. Approximately one-quarter of patients who use insulin report underuse because of cost. In response, more than twenty states have implemented monthly caps on insulin out-of-pocket spending, ranging from $25 to $100. Using a difference-in-differences approach, this study evaluated whether state-level caps on insulin out-of-pocket spending change insulin usage among commercially insured enrollees. The study included 33,134 people ages 18-64 who had type 1 diabetes or who used insulin to manage type 2 diabetes with commercial insurance coverage that was subject to state-level oversight and was included in the 25 percent sample of the IQVIA PharMetrics database during 2018-21. Insulin out-of-pocket caps did not significantly increase quarterly insulin claims for enrollees who had type 1 diabetes or who used insulin to manage type 2 diabetes. State-level caps on insulin out-of-pocket spending for commercial enrollees did not significantly increase insulin use; that may be in part because of out-of-pocket expenses being lower than cap amounts.