Retrospective multicenter case-control study based on collection of clinical and laboratory data. The incidence of complicated coeliac disease was studied among coeliac patients directly diagnosed in four Italian centres. Patients referred to these centres after a diagnosis of coeliac disease and/or complicated coeliac disease in other hospitals were therefore excluded.
Between 1/1999 and 10/2011, 1840 adult coeliac patients were followed up for 7364.3 person-years. Fourteen developed complications. Since five patients died, at the end of the observation period (10/2011), the prevalence of complicated coeliac disease was 9/1835 (1/204, 0.49%, 95% CI 0.2-0.9%). The annual incidence of complicated coeliac disease in the study period was 14/7364 (0.2%, 95% CI 0.1-0.31%). Although complications tend to occur soon after the diagnosis of coeliac disease, Kaplan-Meier curve analysis showed that they can actually occur at any time after the diagnosis of coeliac disease.
Complications of coeliac disease in our cohort were quite rare, though characterised by a very high mortality.