Introduction: To evaluate incremental drug prescription costs before diabetes diagnosis in primary care patients in Germany.
Material and methods: Based on 400 primary care practices throughout Germany (Disease Analyzer, IMS Health, Frankfurt, Germany), we selected only patients receiving continuous treatment (age >or= 40 years) and ascertained drug prescriptions and costs up to 6 years before diabetes was diagnosed. For control, we selected age- and sex-matched nondiabetics (n = 6,294 pairs, age 65.5 +/- 10.5 years, 44 % male). We evaluated incremental prescriptions and costs by calculating differences and ratios between patients with and without a diabetes diagnosis. We also evaluated predictors of cost differences using multivariate regression models. The data used for the evaluation was taken from the period 1993 to 2002.
Results: The mean number of prescriptions in the year preceding diagnosis in men and women increased 15 % and 19 %, respectively (p < 0.001). Prescription costs were 21 % (men) and 28 % (women) higher in subjects who were destined to receive a diabetes diagnosis (269 and 264 Euros per person) compared to controls (p < 0.001). Incremental prescriptions and costs were already present six years preceding diagnosis. Cardiovascular drugs had the largest impact, accounting for about two-thirds of incremental prescriptions and costs. Women had higher numbers of prescriptions and costs, however, differences and ratios were comparable to men. Incremental costs were higher in patients with private compared to statutory health insurance, and in Western compared to Eastern Germany.
Discussion: Numbers of prescriptions and costs in primary care patients with future diabetes diagnosis in Germany were already increased six years before clinical detection, reflecting increased cardiovascular risk even before clinical diabetes diagnosis.