Potential Change in Insulin Out-of-Pocket Spending Under Cost-Sharing Caps Among Pediatric Patients With Type 1 Diabetes

This cross-sectional study estimates the potential change in insulin out-of-pocket spending among privately insured children and young adults with type 1 diabetes if national caps were implemented.

Methods | We conducted a cross-sectional analysis of the 2018 IBM MarketScan Commercial Database, which includes nonelderly patients across the US with private insurance coverage from medium to large employers. 4 We included patients aged 1 to 21 years with continuous enrollment in 2018, 1 or more suggests that insulin demand is inelastic. Third, we assumed that capping insulin out-of-pocket spending would not affect whether and when patients met deductibles or annual out-of-pocket maximums. Finally, we assumed that self-insured employers-who are typically exempted from state-imposed caps under the Employee Retirement Income Security Act-would not be exempted because the cap we modeled was national (ie, instituted by federal legislation). e May not equal difference between the numbers in the 2 rows above due to rounding error.
type 1 diabetes diagnosis codes in 2017 (to limit the population to established patients), and 1 or more insulin pharmacy claims in 2018. The Institutional Review Board of the University of Michigan Medical School exempted this study from review, and informed consent was not required. This article followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline. We calculated mean and median annual insulin out-ofpocket spending (sum of copays, deductibles, and coinsurance) without caps. We assessed changes under national caps that constrained out-of-pocket spending for a 30-day insulin supply to $25 or $100, assuming caps were applied per prescription. Under a $25 cap, we constrained out-of-pocket spending for insulin prescriptions to $25 if days supplied was 30 days or less, $50 if days supplied was between 31 and 60 days, $75 if days supplied was between 61 and 90 days, and so on. Under a $100 cap, the corresponding maximums were $100, $200, and $300, respectively. Under each cap, we determined the proportion of patients who would benefit and changes in annual out-of-pocket spending among those who would benefit. We repeated analyses among high-deductible health plan (HDHP) enrollees and nonenrollees.
We compared proportions and changes in out-of-pocket spending using χ 2 and Wilcoxon rank sum tests. Two-sided P values less than .05 were considered statistically significant. Analyses were conducted using SAS version 9.4 (SAS Institute).
Discussion | In 2018, mean out-of-pocket spending for insulin among privately insured children and young adults with type 1 diabetes was $494; for 1 in 8, spending was more than $1000. For perspective, 40% of those in the US lacked the savings to pay for a $400 emergency in 2018. 5 For 60% and 18% of patients, out-of-pocket spending would decrease under national $25 and $100 caps, respectively. Caps would benefit HDHP enrollees more than nonenrollees.
Caps have limitations. They do not address rising insulin prices, improve insulin affordability for the uninsured, or limit cost-sharing for diabetes-related supplies, such as insulin pumps. Additional policies are needed to alleviate the financial burden among patients with type 1 diabetes.