Diabetes Care, Vol 21, Issue 3 389-397, Copyright © 1998 by American Diabetes Association
Prescription drug use and costs among diabetic patients in primary health care practices in Germany
W Rathmann, B Haastert, JM Roseman, FA Gries and G Giani
Department of Biometrics and Epidemiology, Diabetes Research Institute, Dusseldorf, Germany. rath@dfi.uni-duesseldorf.de
OBJECTIVE: To evaluate drug prescriptions and costs among diabetic patients
in primary care practices in Germany. RESEARCH DESIGN AND METHODS:
Computerized data on prescriptions and costs (drug company sales prices)
were analyzed in 30,604 diabetic and 17,723 (5% random sample) nondiabetic
patients from 362 primary care practices during 1994. Relative use ratios
for drug groups were obtained from logistic regression models (odds ratio
[OR] for diabetes) controlling for age, sex, and other covariates. Relative
costs (diabetic:nondiabetic) were estimated by direct age and sex
standardization. RESULTS: Diabetic patients had an increased prescription
use for most drugs. A substantial increased use (OR > or = 1.4) was
found for cardiovascular drugs, fibrates, gout medication, laxatives, and
wound care products. Diabetic subjects (7.9% of all patients) accounted for
21% of total annual prescription costs in the practices. Total costs (U.S.
dollars) per patient-year were threefold higher (diabetic patients $384;
control subjects $123). After excluding antidiabetic agents and age- and
sex-standardization, relative costs were still 1.5 times higher (P <
0.05). Diabetes treatment accounted for 24% of total costs in diabetic
patients (insulin 12%; oral antidiabetics 6%). The most important cost
factor was cardiovascular drugs (CVDs) (39%). Three CVD groups accounted
for about 50% of total CVD costs in diabetic patients (ACE inhibitors 25%;
Ca-antagonists 16%; nitrates 10%). CONCLUSIONS: Prescription use among
diabetic patients in primary health care practices was predominantly
increased for cardiovascular drugs and for treatment of diabetes-associated
disorders. Diabetic patients accounted for over one-fifth of the total
pharmacy costs in primary practices, indicating that diabetes is a major
economic factor in drug use.