OBJECTIVES: Colorado became the first state to pass a law capping insulin out-of-pocket (OOP) costs at $100 per month. Following Colorado's lead, 22 other states passed the co-pay cap legislation. The insulin co-pay caps in different states limit the OOP costs, ranging from $25 to $100 for a 30-day supply. This study aims to evaluate the impact of OOP costs of insulin on healthcare care resource utilization (HCRU) and healthcare-related costs.

METHODS: A surrogate population based on OOP costs was generated using the Medical Expenditure Panel Survey (MEPS) 2016-2018 to mimic the insulin co-pay cap legislation. Patients diagnosed with diabetes and taking insulin were included in the study. Patients were grouped by their OOP costs of insulin for the 30-day supply. Two cohorts were created considering Utah’s insulin co-pay cap legislation ($0-$30, >$30). Patients with insulin OOP $0-$30 were matched 1:1 with those paying >$30 on age, race, sex, income, education, and marital status. HCRU outcomes included emergency room (ER) visits, office-based visits, and hospital admissions, and cost outcomes included total spending, ER visits, hospitalization, and office visits. HCRU and costs were evaluated with zero-inflated negative binomial regressions and generalized linear models, respectively

RESULTS: Total healthcare spending (co-efficient= $4057, P=0.041) and office visits spending (co-efficient= $947, P=0.05) were higher among patients with insulin OOP >$30. There was no significant difference in spending for ER visits and hospitalization. There was no significant difference in utilization of ER, office-based visits, and hospital admissions.

CONCLUSIONS: Patients with OOP costs >$30 had higher total healthcare and office visits spending. However, this increased spending did not extend to other cost categories, and there is no significant difference in HCRU outcomes. These findings suggest that while higher OOP costs may be associated with increased utilization of specific healthcare services, it does not translate into a broader impact on overall HCRU.