Increased incidence of coeliac disease autoimmunity rate in Israel: a 9-year analysis of population-based data

Background: Incidence rate and temporal trends in coeliac disease and coeliac disease autoimmunity incidence vary worldwide with most data available from North American and European countries. Aims: To explore temporal trends in incidence of coeliac disease autoimmunity and their relation to increase in screening tests in Israel. Methods: A large retrospective population-based study was conducted in Maccabi Healthcare Services, a 2.3-million-member health maintenance organisation operating in Israel. The cohort included all patients with newly diagnosed coeliac disease autoimmunity based on first positive anti-tissue transglutaminase type 2 IgA antibodies. Data were analysed for the years 2007-2015. Results: During the study period (17.3 million person-years), a total of 403 283 patients were tested for coeliac disease autoimmunity, of whom 6444 were positive, representing an average incidence rate of 36.64 per 100 000 person-years (95% CI: 35.74-37.55). Incidence of coeliac disease autoimmunity increased from 25.4 per 100 000 in 2007 to 52.3 per 100 000 person-years in 2015 (Incidence rate ratio of 2.06, 95% CI 1.81-2.26). Coeliac disease autoimmunity incidence was highest in the paediatric age groups, especially in children aged 0-5, and was 4 times higher than the incidence in adults aged 26-55 (Incidence rate ratio of 0.24, 95% CI (0.22-0.26). The increase in incidence surpassed the increase in testing for new patients. Positive trends in incidence were highest in small children, whereas the incidence in adults was stable over the years. Conclusions: There was a steady increase in coeliac disease autoimmunity incidence in our cohort between the years 2007-2015. The paediatric population was the only contributor to this trend.