[High incidence rates of inflammatory bowel disease in Navarra (Spain). Results of a prospective, population-based study].

Introduction: As reflected in the European Collaborative Study on Inflammatory Bowel Disease (1991-1993), differences between northern and southern European countries in the incidence of ulcerative colitis (UC) and Crohn's disease (CD) show a tendency to decrease. No data are available on the current incidence of these diseases in Navarre (northern Spain).

Aim: To determine the present incidence of inflammatory bowel disease (IBD) in Navarra.

Patients And Methods: A prospective, population-based study was performed to determine the incidence of IBD in Navarra between 2001 and 2003. Total population: 569,628 inhabitants (284,620 males). All cases of IBD diagnosed in any public or private hospital in Navarre were included in the study. Crude rates and age- and sex-specific rates adjusted to the European standard population were calculated.

Results: A total of 288 cases were diagnosed (UC 176, CD 102, indeterminate colitis 10). Crude rates of UC, CD and indeterminate colitis were 10.29, 5.96 and 0.58 cases/100,000 inhabitants/year respectively (the population aged 0-14 years of age was included). Specific rates were 9.57 (95% CI, 7.27-12.57) and 5.85 (95% CI, 3.99-8.14) cases/100,000 inhabitants/year for UC and CD, respectively.

Conclusions: The incidence of UC and CD in Navarra has increased in the last decade, with rates close to those of northern European countries and higher than those recently published in Spanish prospective studies.