Dutch diabetes prevalence estimates (DUDE-1)

Background: Recent decades have seen a constant upward projection in the prevalence of diabetes. Attempts to estimate diabetes prevalence rates based on relatively small population samples quite often result in underestimation. The aim of the present study was to investigate whether the Dutch diabetes prevalence estimate of 930 000 for 2013, based on a relatively small sample, still holds true when a larger population is studied using actual prevalence data. Methods: Data were collected from 92 primary care groups, including the total number of people with and without diabetes in 2013. Patients with diabetes were identified using the International Classification of Primary Care codes T90.02 (diabetes mellitus type 2; T2DM), T90.01 (diabetes mellitus type 1) and T90 (diabetes mellitus). Prevalence data were compared with previous estimates made in 2009. Diabetes prevalence was estimated using linear extrapolation. Results: Complete data were available from 67 (73%) care groups, which together provided care for 7 922 403 subjects; 431 396 patients were coded as having diabetes, of whom 406 183 were coded as having T2DM. Based on these results, the extrapolated Dutch diabetes prevalence was 914 387 (5.45%). Conclusions The results show that the previous estimate (reported in 2009), which was based on data collected in 2007, resulted in a <2% (~16 000) overestimation in diabetes prevalence in 2013 compared with the analysis presented. These results indicate that no upward adjustment in Dutch diabetes prevalence estimates is necessary. Repeated large-scale monitoring can help develop more accurate prevalence estimates and improve future prevalence predictions.