Mortality in Inflammatory Bowel Disease in the Netherlands 1991-2002: Results of a Population-Based Study: the IBD South-Limburg Cohort

Background: The aim was to evaluate overall and disease-specific mortality in a population-based inflammatory bowel disease (IBD) cohort in the Netherlands, as well as risk factors for mortality. Methods: IBD patients diagnosed between 1 January 1991 and 1 January 2003 were included. Standardized mortality ratios (SMRs) were calculated overall and with regard to causes of death, gender, as well as age, phenotype, smoking status at diagnosis, and medication use. Results: At the censoring date, 72 out of 1187 patients had died (21 Crohn's disease [CD], 47 ulcerative colitis [UC], and 4 indeterminate colitis [IC] patients). The SMR (95% confidence interval [CI]) was 1.1 (0.7-1.6) for CD, 0.9 (0.7-1.2) for UC and 0.7 (0.2-1.7) for IC. Disease-specific mortality risk was significantly increased for gastrointestinal (GI) causes of death both in CD (SMR 7.5, 95% CI: 2.8-16.4) and UC (SMR 3.4, 95% CI: 1.4-7.0); in CD patients, especially in patients <40 years of age at diagnosis. For UC, an increased SMR was noted in female patients and in patients <19 years and >80 years at diagnosis. In contrast, UC patients had a decreased mortality risk from cancer (SMR 0.5, 95% CI; 0.2-0.9). Conclusions: In this population-based IBD study, mortality in CD, UC, and IC was comparable to the background population. The increased mortality risk for GI causes might reflect complicated disease course, with young and elderly patients at diagnosis needing intensive follow-up. Caution in interpreting the finding on mortality risk from cancer is needed as follow-up was probably to short to observe IBD-related cancers.