Diabetes prevalence from health insurance data: evaluation of estimates by comparison with a population-based...

At present in Germany, data on the prevalence of diabetes can only be obtained by modelling health insurance data. The National Diabetes Register of the former (East) German Democratic Republic which, between 1960 and 1990, monitored approximately 98% of all diabetic subjects, provides a tool for evaluating epidemiological estimates from other data sources. Therefore, the following data bases were compared for the year 1988: (1) a 5% random-sample (n = 6478) of all subjects insured at a local statutory health insurance company in the city of Dormund; (2) related data from the population-based diabetes register of former East-Berlin and (3) of the former German Democratic Republic. All data were standardized by sex and age according to the 1988 population statistics of the Federal Republic of (West) Germany thus resulting in the apparent diabetes prevalence of the Western part of Germany at that time.

total prevalence rates were (1) 4.8%, (2) 4.9%, and (3) 4.4% (p < 0.05). The percentages of insulin-treated patients were (1) 18%, (2) 19%, and (3) 16%, respectively. 54% (1), 37% (p < 0.05) (2), and 42% (p < 0.05) (3), of the patients received oral antidiabetic drugs. It is concluded that the three samples are comparable and that the diabetes prevalence rates as estimated from health insurance data and from the two population-based registers give corresponding conclusions. Sample-based health insurance data may provide a useful and reliable tool for epidemiological studies on diabetes mellitus.