The average price per milliliter of insulin increased by 197% between 2002 and 2013 to $12.92, according to a study reported today in the Journal of the American Medical Association. The authors analyzed individual and prescription-level data from the Medical Expenditure Panel Survey to compare trends in expenditure and price of anti-hyperglycemic medications in the United States from 2002 through 2013. Based on a sample of 27,878 people treated for diabetes, average annual spending for insulin per patient increased from $231 to $736 over the period.