RISING INCIDENCE OF TYPE-1 DIABETES IN SCOTTISH CHILDREN, 1984-93

Objectives - To calculate the incidence of type 1 diabetes in Scottish children aged less than 15 years between 1984 and 1993; to examine ch anges in incidence; and to calculate the prevalence of diabetes at the end af this period. Design - Three data sources were used to construc t the Scottish Study Group for the Care of Young Diabetics register: a ctive reporting of all new cases; reports from the Scottish Morbidity Register 1; and local registers. Subjects - All children resident in S cotland diagnosed with primary insulin dependent diabetes mellitus whe n less than 15 years of age between 1984 and 1993. Main outcome measur e - Annual incidence and prevalence rate for Scotland; time trend in i ncidence over the 10 years; differences in incidence between the three different age groups; and completeness of the register. Results - The average annual incidence far Scotland was 23.9/100 000 children. The prevalence rate was 1.5/1000 in 1993. A total of 2326 cases was identi fied from the three sources, Capture-recapture analysis suggests a cas e ascertainment of 98.6%. The annual incidence rates increased at a ra te of 2% each year (rate ratio = 1.02, 95% confidence interval (CI) 1. 01 to 1.03). The incidence was higher in boys than girls (rate ratio = 1.08, 95% CI 1.00 to 1.18), and the incidence rates increased with ag e: 15.3/100 000/year for age 0-4 years, 24.4/ 100 000/year for age 5-9 years, and 31.9/ 100 000/year for age 10-14 years,Conclusions - The i ncidence of type 1 diabetes in Scotland is increasing and the prevalen ce is relatively high. These findings have important implications for health service resource allocation. The Scottish Study Group for the C are of Young Diabetics' register provides a base for monitoring and re search.