The incidence of type 1 diabetes in Republic of Srpska (Bosnia and Herzegovina) and Slovenia in the period 1998-2010

Objective To establish and compare the incidence and trends of type 1 diabetes mellitus (T1DM) in Republic of Srpska and Slovenia in age group 018 yr from 1998 to 2010. Methods The subjects (413 newly diagnosed T1DM patients in the Republic of Srpska and 664 in Slovenia) were grouped into the age groups: 04, 59, 1014, and 1518 yr. Confidence intervals (CI) for crude incidence rates were estimated assuming numbers of cases were counts from the Poisson distribution. Gender and age-specific standardization was done according to the EURODIAB criteria. Statistical analysis used Poisson-regression models to analyze difference rate between countries and to investigate the incidence trend. Results Case ascertainment was estimated to be 99.95% for the Republic of Srpska and 100% for Slovenia by using the capturerecapture method. The standardized incidence of T1DM for age group 018 yr in the Republic of Srpska was 7.5/100 000/yr (95% CI: 6.88.3). For the same period and the same age group incidence in Slovenia was 12.5/100 000/yr (95% CI: 11.513.5). Annual increase in the incidence in the Republic of Srpska was 2.3% (95% CI: 0.3 to 5.0%), whereas in Slovenia 4.3% (95% CI: 2.26.5%). Conclusion The incidence for age group 018 yr standardized to the world population is remarkably higher in Slovenia than in the Republic of Srpska. Further follow-up and investigations are needed to explain the high difference in incidence of T1DM between the two geographically related countries.