Abstract
Aim Prior to the work of the Irish Childhood Diabetes National Register (ICDNR) there were no reliable data regarding the incidence of Type 1 Diabetes (T1D) in Ireland (a basic WHO health indicator). Limited data suggested Ireland had the lowest incidence in Europe, at 6.8 cases/100,000/year. A 1997 feasibility national incidence study was undertaken prior to the commencement of the ICDNR in 2008. The ICDNR collaborates with EURODIAB. The aim of this study was to report the incidence rates and annual percentage change (APC) since first calculated in 1997 up to the most recent rates in 2021.
Material and Method The 1997 study and ICDNR employed the same methodology. All institutions responsible for the diagnosis and treatment of children with T1D under fifteen years nationally participate and prospectively reported all eligible new T1D cases. Following written informed consent, a detailed case report form was completed, and all cases verified. Following full registration capture-recapture methodology was applied collaborating with the Primary Care Reimbursement and Eligibility Service (PCRES). Standardised incidence rates (SIRs), using the direct method, were calculated to permit comparison internationally and over time. Population data derived from national census data from the Central Statistics Office was employed.
Results The baseline national study found the SIR for all children was 16.3 per 100,000/year, in the top 25% for Europe. In the 11-year period, to 2008, the incidence increased by 69.2% to 27.5/100,000/yr. The annual rate of change varied over the period (table 1).
Conclusions The rate of change in the SIR stabilised, with minor fluctuations to 2018 after which it increased, again prior to and during the COVID-19 pandemic. This pattern is similar to other high incidence countries. In the periods of highest increase, the age category of diagnosis changed from 10–14 years to the younger 5–9.99 year age category, likely due to increased environmental pressure.
