1.3 million US adults with diabetes rationed insulin in the past year

Insulin rationing is common among patients with diabetes, especially younger adults, those of middle income and those who are uninsured, a recent study published in Annals of Internal Medicine found.

“Insulin is life saving for many patients with diabetes, but high prices and inadequate insurance coverage may impede access to it,” Adam Gaffney, MD, MPH, an assistant professor of medicine at Harvard Medical School, and colleagues wrote.

While previous research has suggested that cost-related insulin nonadherence is common, “reliable national data are lacking,” according to the researchers.

To report on the prevalence and correlations of insulin rationing, Gaffney and colleagues analyzed responses from adults with diabetes who participated in the 2021 National Health Interview Survey, which asked respondents whether they skipped insulin doses, took less than needed or delayed buying insulin.

The study included 982 insulin users, representative of 1.4 million adults with type 1 diabetes, 5.8 million adults with type 2 diabetes and 0.4 million adults with unknown or other types of diabetes.

The researchers found that of total insulin users, 1.3 million (16.5%; 95% CI, 13.8%-19.6%) rationed within the last year, with delaying insulin purchases being the most common form of rationing (14.2%).

Among adults aged 65 years and younger, 20.4% reported rationing insulin, a sizeable increase compared with adults aged 65 years and older (11.2%; 95% CI, 8.4%-14.9%).

Middle-income respondents were the highest-reported income group that rationed insulin (19.8%), followed by lower-income respondents (14.6%) and higher-income respondents (10.8%).

Uninsured respondents possessed a rationing rate of 29.2% (95% CI, 14.9%-49.2%), higher than those with private insurance (18.8%), other coverage (16.1%) and Medicare (11.6%).

Gaffney and colleagues reported on factors that likely contributed to results.

“Insulin prices in the United States are far higher than in other nations. Moreover, pharmaceutical firms have increased insulin prices year upon year, even for products that remain unchanged,” they wrote.

Self-reporting of outcomes and diagnosis were among the study limitations, as well as inadequate data on the consequences of insulin rationing — an area that the researchers said requires further investigation.

“By limiting Medicare copays to under $35 a month, the 2022 Inflation Reduction Act may improve insulin access for seniors, who experienced substantial rationing in our study. However, a similar cap for the privately insured was removed from the bill, and copay caps do not aid the uninsured,” Gaffney and colleagues wrote. “Further reform could improve access to insulin for all Americans.”

References:

• 1.3 million American adults with diabetes ration their insulin due to cost; younger adults and the uninsured are most likely to ration. https://www.eurekalert.org/news-releases/967634. Published Oct. 18, 2022. Accessed Oct. 18, 2022.
• Gaffney A, et al. Ann Intern Med. 2022;doi:10.7326/M22-2477.