Colorado IDDM Registry. Incidence and validation of IDDM in children aged 0-17 yr

The purpose of this study was to determine the incidence of insulin-dependent diabetes mellitus (IDDM) among children aged 0-17 yr for age, sex, season, and urban and rural residence of onset in Colorado. Retrospective registration of new-onset cases was conducted from 1978 to 1980, and then prospective registration continued through 1983 with the use of physician reporting with hospital validation. The annual incidence of IDDM was 15.2/100,000 per year (95% confidence interval [CI] 14.1, 16.3), with little difference between the sexes. The highest incidence was in the 10- to 14-yr age-group for both sexes. There was a seasonal peak of winter onset in those aged 10-17 yr, with similar patterns between sex and ethnic groups. No temporal trend over the 6 yr was seen, although an excess of cases was seen for 15- to 17-yr-old boys in 1980-1982. Rates were similar for urban and rural areas of the state. Case ascertainment was estimated to be 93.2% complete (95% CI 91.5, 95.5). Incidence was similar in Colorado to other populations in the United States at similar latitudes. These data serve as a baseline for evaluation of changes in incidence over time, by region, and for the identification of possible outbreaks.