Trends in outpatient prescription drug costs in diabetic patients in Germany. 1994-2004

OBJECTIVE - New antidiabetic medications have been introduced during the last decade, but their impact on health care cost is largely unknown. Prescription costs in diabetic patients in primary care in Germany were evaluated (1994-2004). RESEARCH DESIGN AND METHODS - A total of 46,017 diabetic patients and 46,017 age- and sex-matched control subjects in 400 nationwide practices (2004) were compared with 29,956 diabetic patients and 13,226 control subjects (361 practices) in 1994 (data from IMS HEALTH). Inflation-adjusted age- and sex-standardized costs (ex-manufacturer prices) were calculated. RESULTS - Mean annual total prescription costs per diabetic patient were euro 559 in 2004 (euro 372 in 1994), equaling a 60% (standardized) increase (P < 0.01). Average costs for antidiabetic medication were euro 172 in 2004, a 100% increase (P < 0.01). The major antidiabetic cost factor was insulin and analogs, which accounted for 22% of total drug costs in diabetic patients in 2004 (17% in 1994). All oral antidiabetic drugs together accounted for 8% of total costs (6% in 1994). New drugs (glitazones, glinides, and insulins) accounted for 15% of total costs (40% of antidiabetic drugs) in 2004. A 40% increase (euro 387 vs. 286) in all non-diabetes-related drugs was due mainly to cardiovascular and lipid-lowering drugs. In nondiabetic patients, only a 30% cost increase was found (euro 210 vs. 147; P < 0.01). CONCLUSIONS - Prescription drug costs among diabetic patients increased 60% during the last decade, which was twofold higher than the increase in nondiabetic patients. New types of antidiabetic drugs accounted for a substantial cost share of the overproportional increase for diabetes treatment. Progress in pharmacological therapy is a key driver of drug expenditure growth in diabetes treatment.