RESUMO
BACKGROUND AND OBJECTIVE: Incidence of type 1 diabetes mellitus (DM) varies importantly worldwide, including European countries, and even among regions within a country. The aim of this study is to describe the incidence of type 1 DM in the Madrid Region. MATERIAL AND METHOD: We included 1130 new cases of type 1 DM in children below 15 years of age, which were notified to the diabetes registry from January, 1997 to December, 2005. Case ascertainment was evaluated through the capture-recapture method. The data was analysed using Poisson regression models. RESULTS: The incidence rate in this period was 15.9/100,000 persons-years (95% confidence interval, 15.0-16.8). Completeness of ascertainment was 82%. The incidence by age group was 12.1 (0-4 years), 18.2 (5-9 years) and 17.4 by 100,000 persons-years (10-14 years). The incidence data showed no significant changes in the studied period. We observed a seasonal variation in the incidence, with the greatest incidence in the cold months. CONCLUSIONS: The estimated incidence of type 1 DM ranks in an intermediate position with regard to that estimated more recently in other Spanish regions. During the period 1997-2005, the incidence has maintained stable in the Madrid Region.