The rising incidence of childhood type 1 diabetes in New South Wales, Australia

Objectives: 1, To determine the incidence of type 1 (insulin dependent) dia betes in children aged 0-14 years who were resident in the state of New Sou th Wales, Australia over the period 1992-1996, 2, To analyse the trends in incidence over the period 1990-1996, Methods: Primary ascertainment of patients was performed using a prospectiv e incidence register established in 1990, The secondary source of ascertain ment was the National Diabetes Supply Scheme, a government subsidised schem e for diabetic supplies. Results: There were 1,230 patients identified over the five-year period. Us ing the capture-recapture method, ascertainment was estimated to be 99% com plete. The lowest incidence occurred in 1992 (16.9 per 10(5) person years) and the highest incidence was in 1995 (21.7 per 105), The crude incidence o f IDDM from 1990-1996 was 17.8 per 10(5) and there was a statistically sign ificant rise in the incidence of type 1 diabetes over this period (p = 0.00 03), The annual incidence has increased on average by 3.2% per year since 1 990, Conclusion: The incidence of childhood type 1 diabetes in NSW has increased significantly since 1990.