Incidence of IDDM During 1984–1986 in Population Aged <30 Yr: Residents of Turin, Italy

The goal of this study was to measure the incidence of insulin-dependentdiabetes mellitus (IDDM) during 1984–1986 in residents of Turin, Italy, aged <30 yr. The primary data source was the list of all subjects diagnosed with IDDM who attended diabetes clinics in Turin. Other data sources were the general register of death certificates, the list of hospital discharges, andthe computerized data base of insulin prescriptions. Eighty incident cases of IDDM were identified during the study in 1,130,284 person-yr for those <30 yr of age. Ageadjusted (world standard) incidence rates were 8.05, 8.10, and 6.96/100,000 in the age-groups 0–14, 0–19, and 0–29 yr, respectively. Estimated completeness of the primary data source compared with all other data sources was 91%, whereas the estimated completeness of ascertainment ofthe registry was 99%. Incidence rates of IDDM in northern Italy compare withthose of European countries with low-medium incidence. A population-based register is being established for the province of Turin (951,445 inhabitants aged 0–29 yr) for the collection of incident cases since 1984.