Insulin Analogs: Is Benefit Worth Cost in Type 2 Diabetes?

Miriam E. Tucker

June 10, 2014

The near-universal transition to analog insulins over the past decade has come at increased cost but without clear evidence of benefit for patients with type 2 diabetes, a new nationwide analysis of private health insurance claims data suggests.

Kasia J. Lipska, MD, an endocrinologist from the Yale School of Medicine, New Haven, Connecticut, and colleagues publish their findings in the June 11 special diabetes-themed issue of the Journal of the American Medical Association, timed to coincide with the American Diabetes Association (ADA) 2014 Scientific Sessions, which start in San Francisco on Friday. Dr Lipska will also be presenting this research as a poster at the meeting.

Short-acting insulin analogs may offer more flexible dosing and convenience, and long-acting analogs have been associated with a reduced risk for hypoglycemia compared with synthetic human insulin, say the authors.

But their cost is significantly greater. "Do all these patients find the potential benefits of analogs over human insulin worth the cost? Probably not," Dr. Lipska told Medscape Medical News.

She emphasized that she is not advocating dropping insulin-analog use or curtailing its reimbursement. However, "I do think that we need to be thoughtful and clear about the value of this transition," she added.

"If it's driven by informed patients who benefit from this, great. But I worry that a lot of this transition may have been driven by marketing, not informed patient preferences."

Almost 90% of Enrollees Using Insulin Analogs by 2010

Dr. Lipska and colleagues conducted a retrospective analysis of figures from the Optum Labs Data Warehouse, an administrative claims database of privately insured enrollees from throughout the United States.

Adults aged 18 years or older with type 2 diabetes and at least 2 years of continuous plan enrollment between January 2000 and September 2010 were included. There were 123,486 enrollees who filled at least 1 prescription for insulin, with the proportion doing so rising from 9.7% in 2000 to 15.1% in 2010 (P = .001).

Use of insulin analogs rose from 18.9% in 2000 to 91.5% in 2010 (P < 0.001). At the same time, use of synthetic human insulin dropped from 96.4% in 2000 to 14.8% in 2010 (P < .001) Use of animal insulin was less than 1% during the entire study period.

For all insulins, median out-of-pocket costs per prescription rose from $19 in the year 2000 to $36 in 2010 (P < .001).

There was a drop in the rate of severe hypoglycemic events among insulin users, but this was not significant, falling from 21.1 events per 1000 person-years in 2000 to 17.7/1000 in 2010 (P = .054).

Dr. Lipska cautioned these findings from private health insurance records may not reflect publicly insured populations. For example, analog-insulin use is lower in the Veterans' Administration system, which has a national formulary scheme.

The data also couldn't capture less severe hypoglycemia that did not result in an emergency-department visit or hospital admission, she noted.

"We are absolutely not suggesting that people stop using insulin analogs. But we hope these findings provoke a discussion about the value of healthcare for the overall population of type 2 diabetes patients," she told Medscape Medical News.

Dr. Lipska has received research grants from the Centers for Medicare & Medicaid Services and the National Institutes of Health. Disclosures for the coauthors are listed in the article.

JAMA. 2014;311:2331-2333.


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