Increasing prevalence of coeliac disease in Denmark: a linkage study combining national registries.

AIM To determine the prevalence and incidence of diagnosed coeliac disease (CD) in Danish children and adolescents and to describe trends over time. METHODS All children with a CD diagnosis registered in the Danish National Patient Registry (DNPR) were included in the study. Data were validated by combining this information with registrations of small-bowel biopsies in the National Registry of Pathology (NRP) and with a selected sample of hospital records. RESULTS Data were obtained from 1996 to 2010. The prevalence of CD registered in DNPR increased from 43.2 [95% CI 39.3-47.1] to 83.6 [95% CI 78.4-88.7] per 100,000, and the incidence increased from 2.8 [95% CI 1.9-3.9] to 10.0 [95% CI 8.4-12.0] per 100,000; 56% of the children had at least one biopsy compatible with CD registered in NRP. The incidence of biopsy-verified CD increased from 0.8 [95% CI 0.3-1.4] to 6.9 [95% CI 5.4-8.4] per 100,000. The mean age at diagnosis increased from 5.1 [95% CI 3.5-6.6] to 8.1 [95% CI 7.2-9.0] years of age. The proportion of children with associated diseases did not change over time. CONCLUSION The prevalence of diagnosed CD in Danish children and adolescents has increased over the last 15 years.