Incidence of type 1 diabetes over twenty six consecutive years among 15-39-year-old Lithuanian inhabitants

Abstract

Background and aims: The objective of the study - to document the database of the incidence of type 1 diabetes mellitus in the Lithuanian 15-39-year-old population from 1991 to 2016. Materials and methods: Electronic registration of newly identified patients with type 1 diabetes in the Lithuanian Compulsory Health Insurance Information System was considered as the primary data source. A specifically developed contact system with all general practitioners and family physicians involved in the diabetes care covering 100% of the 15-39-year-old Lithuanian inhabitants registered in primary health care units, was the secondary data source for case ascertainment. Information from all sources was entered into the computer-based information system. The capture-recapture method was employed to detect the number of missing cases and to adjust count for the accurately estimated number of people who had type 1 diabetes. Results: A total of 2424 new cases (1587 males and 837 females) of type 1 diabetes mellitus were recorded among the 15-39-year-old Lithuanian inhabitants during the period 1 January 1991-31 December 2016. The overall completeness of case ascertainment was estimated at 78.86%. The cumulative incidence density per person-year was 7.59/100,000 (95% Poisson distribution confidence interval (CI) was 6.93-7.50) and was slightly higher among males (9.88/100,000, 95%CI 8.94-9.86) than among females (5.02/100,000, 95%CI 4.69-5.37), p<0.0001. World Standard Population standardized age-adjusted overall incidence rates for males and females were 9.71 and 5.07, respectively. The male/female ratio was 1.85. Results from linear regression models showed that the incidence density for type 1 diabetes mellitus in the 15-39-year-old Lithuanian inhabitants had a pronounced tendency to decrease. Conclusion: Our data demonstrated the male predominance in the primary incidence of type 1 diabetes mellitus in 15-39-year-aged population in Lithuania. The incidence density [...].