Insulin underuse due to costs remains high in primary care settings

In a recent survey, nearly half of primary care patients with type 1 or type 2 diabetes reported suboptimal insulin use due to costs.

According to Tess Willcoxon, a student at East Tennessee State University Bill Gatton College of Pharmacy, and Rick Hess, PharmD, CDCES, BCACP, an associate professor at the same institution, previous research has shown that high costs of insulin contribute to a lack of patient treatment. For example, a 2019 JAMA Internal Medicine study found that 25% of patients with diabetes receiving care at an endocrinology clinic reported cost-related insulin underuse.

“It is less clear, however, what the frequency of cost-related suboptimal insulin use is among an older primary care population where the vast majority have [type 2 diabetes],” Willcoxon and Hess wrote in Annals of Family Medicine.

The researchers administered a 29-item survey to 90 patients in a primary care setting in Tennessee who had been diagnosed with type 1 diabetes or type 2 diabetes within the last year and were prescribed insulin. The participants had a mean age of 68 years and 59% were men. Most had type 2 diabetes (83%), and the monthly out-of-pocket cost for prescription was $84.10.

Overall, Willcoxon and Hess found that 44% of the primary care patients reported experiencing cost-related suboptimal insulin therapy.

Speaking to Healio, Hess said the overall underuse was surprising.

“I expected cost-related insulin underuse in the Appalachian population to be high, but I would not have predicted it be as high as 44%,” he said.

Respondents who reported underuse were more than nine times likely to have difficulty purchasing diabetes supplies (OR = 9.4; 95% CI, 2.6-34.1). In addition, 76% of those dealing with cost-related issues reported discussing it with their providers, which impacted the likelihood of them changing their insulin (OR = 8.4; 95% CI, 1.6-15).

Willcoxon and Hess noted that the higher number of respondents reporting cost-related suboptimal insulin use in their study compared with the JAMA Internal Medicine study “could be due to the differences between study populations as our respondents were older and a larger majority diagnosed [with type 2 diabetes].”

Additionally, “most respondent characteristics were not associated with increased insulin underuse including poor diabetes control,” they wrote. “This finding could be a result of a smaller sample size.”

Hess said that “insulin still remains one of medicine’s all-time greatest discoveries,” but “barriers to its use in primary care today seem to go beyond the fact that it is administered by injection and may cause hypoglycemia.”

“There is the problem with access to insulin that I believe is not assessed in every patient the same way as their blood glucose would be evaluated,” he said. “I feel the best strategy to reduce this barrier is for primary care providers to ask the patient’s opinion about the cost of their medications and not just once, but with every visit.”

Hess encouraged physicians to use a “normalization technique” when asking patients about costs, such as, “I have patients who tell me the price of their diabetes medications is too high. Have you experienced that before?”

“This will allow you to identify those patients at risk for cost-related underuse,” he said.

Willcoxon and Hess referenced ongoing federal efforts to eliminate cost barriers. Those include the Affordable Insulin Now Act that, if signed into law, would require private health groups and insurers to cap insulin copays at $35 per month.

Through the Inflation Reduction Act, insulin copays are already capped at $35 per month for Medicare Part D beneficiaries. Starting July 1, the $35 cap will be extended to Part B beneficiaries.

However, the researchers wrote that the costs of non-insulin diabetes medications are rising, meaning that patients who are not treated with insulin could still experience cost-related barriers to treatment.

Study limitations included a small response rate, recruitment methods being affected by the COVID-19 pandemic and nonadherence being underestimated if participants were not truthful about insulin prescription behaviors, according to the researchers.

“Nevertheless, our results indicate insulin underuse remains a significant problem in the primary care setting,” they concluded.

References:

• Herkert D, et al. JAMA Intern Med. 2019;doi:10.1001/jamainternmed.2018.5008.
• Saving money with the Inflation Reduction Act. https://www.medicare.gov/about-us/inflation-reduction-act. Accessed Jan. 25, 2023.
• Willcoxon C, Hess R. Ann Fam Med. 2023;doi:10.1370/afm.2899.