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One in 4 patients with diabetes underuse insulin due to cost

Approximately 25% or patients with type 1 or type 2 diabetes reported cost-related insulin underuse, which was associated with poor glycemic control, according to a study published in JAMA Internal Medicine.

“Insulin is lifesaving for people with diabetes and is included on the Model List of Essential Medicines formulated by the World Health Organization,” Darby Herkert, BS, from Yale College, and colleagues wrote. “This means it should be available at all times at a price the individual and the community can afford. However, over the past decade, insulin prices have tripled in the United States, while out-of-pocket costs per prescription doubled. High costs of medications can contribute to nonadherence, but the prevalence of cost-related insulin underuse is unknown.”

Herkert and colleagues investigated the association between sociodemographic, economic and clinical factors and cost-related underuse of insulin, as well as the association between cost-related underuse and poor glycemic control, defined as having an HbA1c of 9% or more at the time of visit or within 3 months.

They administered a survey to 354 patients (52% women; 54% white) with type 1 (34.8%) or type 2 diabetes (65.2%) who were prescribed insulin within the past 6 months and visited the Yale Diabetes Center between June and August 2017. The survey was completed by 199 patients (56.2%; 50.8% women; 60.8% white; 41.7% with type 1 diabetes).

Participants were asked if they underused insulin in the past 12 months due to cost-related reasons; specifically, if they used less insulin than prescribed, tried to prolong their insulin, took smaller doses of insulin than prescribed, ceased using insulin, did not fill an insulin prescription or failed to initiate insulin because of cost.

Overall, 25.5% of participants (n = 51) reported underusing insulin due to cost. There was no significant association between the type of prescription drug coverage and cost-related underuse.

Patients with lower incomes were more likely underuse insulin because of cost. More than one-third of these patients did not discuss the cost of insulin with their physician and only 29.4% opted to change their insulin type to one with a lower cost.

In a multivariable analysis that adjusted for sex, BMI, diabetes duration and income, poor glycemic control was more common among patients who reported cost-related underuse compared with those who did not (43.1% vs. 28.1%; OR = 2.96; 95% CI, 1.14-8.16).

“These results highlight an urgent need to address affordability of insulin,” Herkert and colleagues concluded.

“Insulin is a life-saving, essential medicine, and most patients cannot act as price-sensitive buyers,” they added. “Regulators and the medical community need to intervene to ensure that insulin is affordable to patients who need it. At minimum, individual clinicians should screen all patients for cost issues to help them address these challenges.” – by Alaina Tedesco

Disclosures: Herkert reports no relevant financial disclosures. Please see study for all other authors’ relevant financial disclosures.