Yale researchers have found that despite new policies addressing insulin costs, the proportion of patients who ration insulin due to cost remains unchanged.
The findings were published in the Journal of General Internal Medicine.
For those with type 1 diabetes, insulin is necessary for survival, explains Yale School of Medicine’s Kasia Lipska, MD, MHS, the study’s corresponding author.
Insulin is also essential for many individuals with type 2 diabetes, who use it to control their blood sugars. The medicine, which was discovered more than 100 years ago, should be available, accessible, and affordable for all those with diabetes, Lipska says.
“When people don’t have enough money for insulin, they may ration it, meaning they take less than is prescribed to make it last longer, or skip it altogether,” says Lipska, associate professor of medicine (endocrinology and metabolism). “This can lead to devastating consequences for people who rely on insulin to stay healthy.”
For the study, the researchers conducted a survey at the Yale Diabetes Center to assess rates of insulin rationing due to barriers including high cost, insurance delays, and pharmacy shortages.
They compared the answers from 199 respondents in 2024 with 199 respondents in a previous survey study they conducted in 2017. Despite new governmental policies that have been introduced since 2017 to limit out-of-pocket costs for insulin, the researchers found that one in four patients at the center rationed insulin due to cost in 2024, a rate unchanged from 2017.
While the researchers examined the experiences of patients at the center, high prices are an issue for many of the 38 million people across the U.S. who have diabetes and for the clinicians who care for them, Lipska says.
The findings suggest that the legislative changes implemented to lower the cost of insulin may have a limited impact, Lipska says.
As an example, she points to the Inflation Reduction Act. The law, which caps insulin copays, applies only to Medicare beneficiaries and does not help most younger individuals because few under the age of 65 qualify for Medicare. In addition, Lipska says, each copay cap applies to only one type of insulin, meaning individuals who use multiple types must pay separate copays for each.
Other policy changes, such as state co-payment caps, do not benefit individuals who are uninsured or enrolled in self-insured or out-of-state plans, Lipska says.
“People assume that no one is paying more than $35 for their insulin anymore, but that’s just not true,” Lipska says. “Patients are still having issues, and this tells us that our current policies are not enough to turn the tide.”
To make matters worse, Lipska adds, many insulin manufacturers have turned their focus to the newer, more profitable weight loss medications, increasing the potential for pharmacy shortages of the life-saving drug.
“When we combined insulin rationing for three reasons—high costs, pharmacy shortages, and insurance delays—we found that 37% of patients reported rationing over the last year,” Lipska says. “Cost is certainly the largest issue, but there are other barriers to accessing insulin that we need to address.”
The study’s first authors are postgraduate research fellow Sefia Khan and chief resident Nadera Rahman, MD. Other Yale authors include Laura Nally, MD, and Darren Warren.
Endocrinology and Metabolism, one of 10 sections in the Yale Department of Internal Medicine, works to improve the health of individuals with endocrine and metabolic diseases by advancing scientific knowledge, applying new information to patient care, and training the next generation of physicians and scientists.
Serena Crawford is associate director, Communications, Yale School of Medicine. This story is used through cooperation with the school.