OBJECTIVE To provide reliable data on the incidence and prevalence of insulin–dependent diabetes mellitus (IDDM) in children in Slovakia.

RESEARCH DESIGN AND METHODS A total of 754 Slovak children with IDDM, aged 0–14 years, were identified during an 8-year study period. There were 369 boys and 385 girls from an average population of 1,363,499 children. All patients were prospectively recorded. The primary ascertainment was based on notifications by physicians from outpatient departments. The second independent source of information was from all hospitals where the diabetic patients were hospitalized. The completeness of ascertainment was based on the capture-recapture procedure.

RESULTS The completeness of the ascertainment was 95%. In 1992, the annual incidence rate of IDDM (per 100,000) in the 0- to 14-year-old age-group was 8.92 for both sexes (7.95 for boys and 9.93 for girls). In the youngest age-group, an increase in the incidence rates from 2.89 in 1985 to 6.54 in 1992 was observed. Seasonality, with a higher incidence in autumn and winter, was observed in children older than 4 years. The prevalence rates of IDDM (per 1,000) were 0.28–0.50% in the 8-year period.

CONCLUSIONS The incidence of IDDM in Slovak children (0–14 years) is similar to what has been found in other Central European countries. In children younger than 4 years of age, in the last 2 years (1991 and 1992) more patients with diabetes were found than in any period during the preceding 6 years. The recent conspicuous increase in the incidence of IDDM among the younger children in Slovakia urges us to study its mechanisms, so far unknown, and to search for possible means of prevention.