The average adult with diabetes spends $2,790 more a year treating the disease than they did in 1987, according to a new study conducted by researchers at the Centers for Disease Control and Prevention. The study is published in the journal Diabetes Care.

The researchers used the National Medical Expenditure Survey and the Medical Expenditure Panel Surveys from 1987, 2000-2001, and 2010-2011 to compare per person medical expenditures and uses among adults ≥18 years of age with and without diabetes at the three time points.

Prescription medication costs accounted for 55% of the increase.  Inpatient visits accounted for 24%, outpatient visits accounted for 15%, and ER visits and other medical spending accounted for 6%, the researchers found. The growth in prescription medication spending was due to the increase in both the volume of use and unit cost, and the increase in outpatient expenditure was almost entirely driven by more visits. The increase in inpatient and ER expenditures was caused by the rise of unit costs, the researchers found.