Switch from analogue to human insulin reduces part D coverage gap risk for Medicare beneficiaries

ORLANDO, Fla. — Medicare beneficiaries with type 2 diabetes switched from analogue to human insulin were less likely to reach the spending limit for their Part D drug plan — commonly known as the “donut hole” — with no changes in hospitalization rates for hypoglycemia or hyperglycemia and only a slightly increased mean HbA1c, according to a speaker here.

“The unit price of insulin has risen dramatically across a variety of settings, and while newer analogue insulins are more expensive than comparable human insulin products, they may not result in substantially improved clinical outcomes for most patients with type 2 diabetes,” Jing Luo, MD, MPH, professor of medicine at Harvard Medical School and a faculty member in the division of pharmacoepidemiology and pharmacoeconomics in the department of medicine at Brigham and Women’s Hospital, said during a presentation at the American Diabetes Association Scientific Sessions.

Luo and colleagues analyzed data from 14,635 participants who filled 221,866 insulin prescriptions between 2014 and 2016, identified from the CareMore Medicare Advantage and prescription drug plan operating in Arizona, California, Nevada and Virginia (mean age, 73 years; mean baseline HbA1c, 8.46%). In 2015, CareMore piloted an intervention to switch members from analogue to human insulin after an increase in insulin prices, Luo said.

“At the time, most members were using higher-cost insulin analogues and prices were driving many of these members into the Part D coverage gap, also known as the donut hole,” Luo said. “The objective was to evaluate the effectiveness of this intervention on clinical and economic outcomes.”

Providers switching patients from analogue to premixed human insulin were advised to stop sulfonylurea therapy if prescribed and start premixed insulin at 80% of the total daily dose, Luo said, with two-thirds given at breakfast and one-third at dinner. Outcomes were mean HbA1c, rates of severe hypoglycemia or hyperglycemia events and risk of reaching the Part D coverage gap. Researchers used an interrupted time series method and segmented regression analyses, with cut points at the beginning and end of 2015.

Within the cohort, the fill rate for analogue insulins decreased from 90% to 30% during the intervention, Luo said.

During 2014, mean HbA1c for patients switched to human insulin decreased at a rate of –0.02% per month, Luo said. The beginning of the conversion program in 2015 was associated with a mean level change of 0.14% (P < .01) and a slope change of 0.02% (P < .01).

The baseline rate of severe hypoglycemia was 4.21 per 1,000 person-years and increased at a rate of 0.36 per 1,000 person-years during 2014. The baseline rate of severe hyperglycemia was 22.33 per 1,000 person-years and increased at a rate of 0.3 per 1,000 person-years. For both hypoglycemia and hyperglycemia, the level and slope changes during the 12-month intervention and postintervention segments were not statistically significant, Luo said.

For 2016, patients switched from analogue to human insulin were 55% less likely to reach the Medicare Part D coverage gap (HR = 0.45, 95% CI, 0.43-0.48), Luo said.

In a sensitivity analysis of switchers vs. nonswitchers, there were no between group differences for HbA1c and clinical outcomes, Luo said.

“Patients with type 2 diabetes and their clinical providers should strongly consider human insulin as a clinically viable and cost-effective option,” Luo said. – by Regina Schaffer

Reference:

Luo J, et al. 4-OR. Presented at: American Diabetes Association 78th Scientific Sessions; June 22-26, 2018; Orlando, Fla.

Disclosures: Luo reports he is a consultant for the nonprofit organization Alosa Health Inc. and has received money from Health Action International for travel. Please see the abstract for the other authors’ relevant financial disclosures.