Epidemiology of Complications and Total Treatment Costs from Diagnosis of Type 2 Diabetes in Germany (ROSSO 4)

Abstract

To determine the occurrence of complications and treatment costs in the first 6 years from diagnosis of Type 2 diabetes in the primary care level. The German multi-centre, retrospective epidemiological cohort study ROSSO observed patients from diagnosis in 1995-1999 until the end of 2003 or loss to follow-up. 192 randomly contacted primary care practices and all patient records of newly diagnosed type 2 diabetes patients. All 3,142 patients insured in a public health insurance plan. Diabetes-related complications were documented from patient files. Treatment costs were attributed using the doctor's tariff, hospital DRGs and medication price lists for Germany. At diagnosis, already 22.4% of patients presented with CHD, 15.4% with CHF, 5.8% with pAOD, 3.1% with stroke and 3.9% with AMI, but less than 0.5% with documented microvascular complications. 7.4% of patients were diagnosed with prior depression and, 5.0% with polyneuropathy. Within a mean of 6.5 years of follow-up 114 patients (3.6%) died. The cumulated occurrence of AMI and stroke rose without a lag phase almost linearly from diagnosis reaching 6.7% for AMI and 7.7% for stroke. The total number of strokes was significantly higher than AMI (181 strokes vs. 109 AMI; p</=0.001). As expected, the rate of microvascular complications was low during this early disease stage but nevertheless reached 2.8 % of patients (amputation, dialysis and blindness combined). Mortality and stroke rates did not differ significantly between sexes but men suffered more frequently from AMI (4.8% men, 2.2% women; p < 0.001). Total costs of diabetes care was 1,288 euro (1,610 $)for the first treatment year with diagnosed diabetes and rose to 3,845 euro (4,806 $) in year seven. Costs for treating complications dominated already in the first year after diagnosis. The mean direct treatment costs amounted to 3,210 euro (4,013 $) per patient and year for the first 6.5 years. ROSSO is the first epidemiological cohort study examining longitudinal epidemiological data of the same patients over more than five years (up to eight years) for type 2 diabetes mellitus in primary care practices, starting from diagnosis. The rate of complications rose linearly from diagnosis without a lag phase. Stroke occurred more often than myocardial infarction, the latter more often in men. Total treatment costs were dominated by costs of treating complications from early on, suggesting a costs saving potential by early detection of diabetes as well as by secondary prevention and patient empowerment in the period following diagnosis.