ANALYSIS OF THE GEOGRAPHIC-DISTRIBUTION O F THE INCIDENCE OF DIABETES-MELLITUS TYPE-I IN CATALONIA (SPAIN)

BACKGROUND: The aim of the present study was to evaluate the geographi c distribution of the incidence of diabetes mellitus type I (DMI) in C atalonia from 1987-1990. METHODS: The base of the study is the Catalon ian registry of incidence of DMI in the period from 1987-1990. The def inition criteria were: diagnostic criteria of diabetes (WHO norms 1985 ), age of diagnosis under 30 years, residence in Catalonia in the peri od of diagnosis and exclusion of other types of diabetes. The populati on at risk was estimated according to the general census of the popula tion of 1986. The total incidence of Catalonia was calculated by provi nces and counties according to the Poisson distribution. RESULTS: The incidence of DMI observed in Catalonia was of 11.5/100,000 inhabitants per year (CI 95 %, 10.6-12.4) in the age group from 0-14 years and 10 .7/100,000 inhabitants per year (CI 95 % 10.1-11.3) in the age group f rom 0-29 years. The exhaustivity in the detection of the cases was of 90.3 %. No differences were found in interprovincial incidence in the 0-14 age group: Barcelona 11.6 (10.6-12.7), Girona 10.2 (7.2-13.4), Ll eida 11.7 (7.7-15.8), Tarragona 10.5 (7.6-13.5). In the 15-29 age grou p a lower incidence was observed in Tarragona. The incidence by counti es varied between 2.9 and 15.0/100,000 inhabitants per year with those of greatest incidence being observed in the Valles Oriental (15.0/100 ,000 inhabitants/years), Alt Penedes (14.5/100,000 inhabitants/year), Segria (15.0/100,000 inhabitants/year) and the Priorat (13.7/100,000 i nhabitants/year). CONCLUSIONS: No differences were found in the incide nce of diabetes mellitus type I in the four Catalonian provinces. Dist ribution by counties was more heterogeneous without defining zones wit h a much higher incidence to that observed in the whole of Catalonia.