[Incidence of inflammatory bowel disease in the health area of Navalmoral de la Mata (Caceres, Spain) between 2000 and 2009]

Abstract

Objectives: To determine whether the incidence of inflammatory bowel disease (IBD) has changed in our area and whether it has been influenced by the growing immigrant population.

Population and methods: From 2000 to 2009, a prospective population-based study was conducted in the population aged over 15 years old and was compared with a study carried out from 1994 to 1998 in the health area of Campo Arañuelo. The distribution of Crohn's disease (CD), ulcerative colitis (UC) and age and sex were analyzed and compared with European rates for the standard population, both for the total population and for the local population.

Results: From 2000 to 2009, IBD was diagnosed in 73 patients (36 men and 37 women). CD was diagnosed in 25 patients (34.2%), UC in 46 (63.0%) and there were two cases (2.8%) of indeterminate colitis (IC), which were excluded from the analysis. The mean annual incidence of CD was 5.70 per 100,000 inhabitants (5.79 in men and 5.60 in women). The annual incidence of UC was 11.47 per 100,000 inhabitants (10.79 in men and 12.17 in women). The incidence of UC was significantly higher than that of CD. The UC/CD ratio was 1.87. The mean age of patients with CD was 31.44 ± 15.81 years (range: 15 to 79 years), which was significantly lower than that for patients with UC: 43.26 ± 18.63 years (range: 15 to 85 years), with a difference of 11.82 years (confidence interval [CI]: 3.05-20.59 years). No immigrants were diagnosed. The incidence related to the total population aged between 15 and 64 years old was 5.74 per 100,000 inhabitants per year (95% CI: 3.43-8.04) in CD and 9.48 per 100,000 inhabitants per year (CI: 5.63-13.32) in UC. The incidence related to the local population aged between 15 and 64 years old was 5.90 per 100,000 inhabitants per year (95% CI: 3.52-8.28) in CD and 9.75 (CI: 5.80-13.70) in UC.

Conclusions: The incidence of UC in our area is one of the highest in Spain. Although this incidence is lower than that from 1994 to 1998, this decrease is not significant. The number of CD cases has not increased. Both diseases affect men and women equally. CD is diagnosed in earlier ages than UC. Exclusion of immigrants from the study increases these rates but not significantly.