Unusually High Incidence of Paediatric Coeliac Disease in Sweden during the Period 1973 - 2013.

OBJECTIVE: The prevalence of coeliac disease in Sweden during the "epidemic period" (1984-1996) was one of the highest in the world. The aim of this study was to assess the coeliac disease incidence in our region over the 41-year period, and how diagnostic activity and diagnostic accuracy were affected by the introduction of antibody testing. We also looked into how patients with mild enteropathy were evaluated. METHODS: In the county of Östergötland in Sweden, 2790 paediatric patients were investigated for suspected coeliac disease between 1973 and 2013. Notes were scrutinised for data on sex, age, histopathological reports and final diagnosis. For comparative purposes this period was divided into three sub-periods (1973-1983, 1984-1996 and 1997-2013) named pre-epidemic, epidemic and post-epidemic. RESULTS: Coeliac disease diagnosis was received by 1,030 patients. The peak incidence rate, 301 cases/100,000 in 1994 for the age group 0-1.9 years is the highest figure ever reported. The other age groups, 2-4.9, 5-14.9, and 15-17.9 years, also had high incidence rates. After the 1984-1996 "epidemic period" the incidence decreased for the youngest group but continued to increase for the other groups. The cumulative incidence at 18 years-of-age for children born during the epidemic reached 14 cases/1000 births, the highest figure hitherto reported. Diagnostic activity differed significantly between the three sub-periods (p<0.001) increasing gradually from 1984 and reaching a peak value of 0.87 in 2012. Cases of mild enteropathy were more frequently regarded as non-coeliac disease cases, decreasing significantly in the "post-epidemic" period (p<0.001). CONCLUSIONS: The incidence rate and cumulative incidence of coeliac disease were possibly the highest ever reported. Changes in diagnostic activity and accuracy could not be attributed to the introduction of new antibody tests, possibly because of other changes e.g. variations in the symptoms at presentation and improved knowledge of the disease among parents and health professionals.