For adults with type 2 diabetes, the out-of-pocket cost of each insulin prescription and refill nearly doubled during a 10-year period, rising from $19 to $36, according to a research letter to the editor published online June 11 in JAMA.
Using information from the Optum Labs Data Warehouse, an administrative claims database of privately insured patients throughout the United States, investigators calculated the proportion of 123,486 adults with type 2 diabetes who purchased every type of insulin each year from 2000 through 2010.
"We found a large increase in the prevalent use of insulin analogs," said Dr. Kasia J. Lipska, an endocrinologist in the department of internal medicine, Yale University, New Haven, and her associates.
In 2000, only 18.9% of these patients filled (and refilled) prescriptions for insulin analogs. By 2010, that proportion had risen to 91.5%. Correspondingly, out-of-pocket expenditures for insulin therapy increased from $19 to $36. However, the rate of severe hypoglycemic events in insulin users did not decline significantly in that time, going from 21.1 to 17.7 events per 1000 person-years. "The clinical value of this change is unclear," they noted (JAMA 2014;311:2331-3).