Trends in Use of Pharmaceutical Therapies for Diabetes, 1997-2007

The recommended treatment goal for patients with diabetes is hemoglobin (Hb) A1C <7%. For patients with type 1 diabetes, the standard treatment is insulin, whereas patients diagnosed with type 2 diabetes follow a stepwise treatment regimen to reach that goal. Current guidelines call for initial treatment with lifestyle modification plus metformin. Other oral medications are added as necessary to achieve HbA1C <7%. Diabetes is a chronic and progressive disease that involves significant morbidity, mortality, and healthcare costs. The Agency for Healthcare Research and Quality recently published Statistical Brief #293, Trends in the Pharmaceutical Treatment of Diabetes: A Comparison of Utilization and Expenditures, 1997 to 2007. The brief presents data from the Household Component of the Medical Expenditure Panel Survey on trends in the use of antidiabetic medications as well as expenditures in the US civilian noninstitutionalized population from 1997 to 2007. The sample includes individuals with an International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnosis of diabetes (ICD-9-CM codes 249, 250) who reported treatment for diabetes during the year. Data on trends of medication use are provided for oral medication, insulin, and noninsulin injectables, in addition to the subclasses of oral medications. The expenditures for all years are expressed in constant dollars, by inflating them to 2007 US dollars using the Consumer Price Index for All Urban Consumers. Of the respondents reporting treatment for diabetes, 13.1% reported cardiovascular disease in 1997, compared with 17.2% in 2007. The proportion of those reporting treatment for diabetes who also reported hypertension was 46.1% in 1997, compared with 64.8% in 2007; for hyperlipidemia, the proportions were 15.0% in 1997, compared with 52.8% in 2007. The number of patients with diabetes who reported using oral antidiabetic medications more than doubled from 1997 to 2007. In 1997, 5.9 million reported using oral medications to control their diabetes; in 2007, that number was 14.6 million. In 1997, 3.7 million patients with diabetes were being treated with insulin; in 2007, there were 4.6 million patients with diabetes using insulin. There were 59.9% of patients with diabetes using oral medications in 1997; 77.3% were using oral medications in 2007. The proportions of patients with diabetes being treated with insulin decreased over the time period from 38.2% in 1997 to 24.4% in 2007. In 2007, 4.1% of patients with diabetes were using noninsulin injection to control their disease. The number of patients reporting treatment for diabetes with oral antidiabetic medications has changed over the time period. In 1997, 5.0 million reported using sulfonylureas, 2.1 million reported using biguanides, and 0.5 million thiazolidinediones. In 2007, the numbers were 7.6 million using sulfonylureas, 10.4 million using biguanides, and 4.6 million using thiazolidinediones. The proportions changed accordingly over the time period: in 1997, 51.2% of patients using oral antidiabetic medications were using sulfonylureas, 21.2% were using biguanides, and 4.7% were using thiazolidinediones. By 2007, the corresponding proportions were 40.2%, 55.2%, and 24.6%, respectively. The mean cost per user to all types of antidiabetic medications was $500 in 1997 compared with $944 in 2007. The mean expenditure for insulin in 1997 was $331, compared with $918 in 2007. The mean cost for sulfonylureas in 1997 was $298, compared with $211 in 2007; the mean cost for biguanides was $381 in 1997, compared with $297 in 2007. The mean expenditure for thiazolidinediones was $1013 in 1997, compared with $1121 in 2007. For patients using newer antidiabetic medications in 2007, the mean expenditures per user costs were $1297 for noninsulin injections and $577 for oral combinations. The mean out-of-pocket expenditure on medications prescribed for the treatment of diabetes was $221 in 1997 compared with $273 in 2007. For insulin, the mean out-of-pocket expenditure was $132 in 1997 and $257 in 2007; mean out-of-pocket expenditures on thiazolidinediones were $190 in 1997 and $250 in 2007. During that time period, mean out-of-pocket expenditures on sulfonylureas and biguanides decreased, from $167 and $174 in 1997 to $89 and $116 in 2007, respectively. In 2007, mean out-of-pocket expenditures on noninsulin injections were $258; for combination antidiabetic medications, the mean out-of-pocket expenditures were $179 in 2007.