LAUSR

Insulin is considered an essential medicine for people with diabetes, but its price has doubled during the past decade, posing substantial financial barriers to patients in the US. In this article we describe out-of-pocket spending on insulin and consider risk factors that could contribute to the likelihood of a person experiencing catastrophic spending, defined as spending more than 40 percent of their postsubsistence family income on insulin alone. Using nationally representative data from the 2017 and 2018 Medical Expenditure Panel Surveys, we examined out-of-pocket spending on insulin among people who filled at least one insulin prescription. Among Americans who use insulin, 14.1 percent reached catastrophic spending over the course of one year, representing almost 1.2 million people. Nearly two-thirds of patients who experienced catastrophic spending on insulin were Medicare beneficiaries. Catastrophic spending was 61 percent less likely among Medicaid beneficiaries than among Medicare beneficiaries, suggesting that factors other than income, such as different types of insurance coverage, may influence catastrophic insulin spending. Policy reform is needed to curb out-of-pocket spending, especially for Medicare beneficiaries and people with low incomes, who appear to be particularly vulnerable to catastrophic spending.