Occurrence of inflammatory bowel disease in central Italy: a study based on health information systems.

BACKGROUND: The burden of inflammatory bowel diseases, including Crohn's disease and ulcerative colitis, has never been estimated in Italy using administrative data sources. Our objective was to measure the occurrence of inflammatory bowel diseases in the Lazio region (Italy) using administrative data and to test the sensitivity of the Crohn's disease case-finding algorithm with respect to clinical diagnosis.

METHODS: We conducted a population-based cross-sectional study identifying prevalent and incident cases. We estimated occurrence rates of inflammatory bowel diseases using hospital discharges or activation of copayment exemptions. Sensitivity was calculated from 2358 subjects with clinical diagnosis of Crohn's disease.

RESULTS: Exemptions identified more than 20% of the cases. Prevalence rates (per 100,000) on December 31, 2009 for males and females were 177 and 144 for ulcerative colitis and 91 and 81 for Crohn's disease, respectively. The incidence rates during the years 2008-2009 were 14.5 and 12.2 for ulcerative colitis and 7.4 and 6.5 for Crohn's disease for males and females, respectively. The sensitivity of the administrative sources was 82.2%.

CONCLUSIONS: Health and population data sources allow the estimation of inflammatory bowel diseases occurrence. The age-specific peaks of diagnosis were consistent with those reported in other studies. Sensitivity may be affected by temporal changes in the quality of the data sources.