Benoit Follin-Arbelet [1,2], Milada Småstuen Cvancarova [2,3], Øistein Hovde [2,4], Lars-Petter Jelsness-Jørgensen [5,6], Bjørn Moum [1,2]

Affiliates

Oslo University Hospital, Department of Gastroenterology [1], University of Oslo, Institute of Clinical Medicine [2], Oslo Metropolitan University, Department of Public Health [3], Innlandet Hospital Trust, Gjøvik [4], Østfold University College [5], Østfold Hospital Trust [6]

Abstract

Background: Previous longitudinal studies have shown increased mortality in patients with inflammatory bowel disease (IBD).
The objectives of this study were to determine overall and cause specific mortality risk rates in the IBSEN cohort 30 years after diagnosis compared to the general population.

Methods: The IBSEN study included all incident IBD patients from four Norwegian counties from January 1990, to December 1993. All patients were age- and gender- matched with five controls from the same county.
Mortality data was obtained from the Norwegian Cause of Death Registry. Causes of death were categorised as: all cancers, gastrointestinal cancers, cardiovascular diseases, infections, or all other causes.
Difference in cumulative mortality was assessed using the log-rank test. Mortality Hazard Ratios (HR) were modeled with conditional Cox regression stratified by matched sets.

Results: 519 patients with ulcerative colitis (UC) and 237 with Crohn’s disease (CD) were included. There was no difference in overall mortality rate for IBD patients and matched controls (p=0.2). However, male CD patients showed elevated mortality compared to their controls (Table 1).
When CD patients were stratified according to clinical characteristics, elderly onset, colonic disease, and penetrating behavior were associated with higher mortality rates.
IBD patients were at a higher risk of death due to cardiovascular disease.
Infection was not significantly more frequent in patients compared to their matched controls. Additionally, infection was often a secondary cause of death when IBD was recorded as the main underlying cause (n=6).
Mortality due to all malignancies was not significantly increased although it was observed an elevated incidence of all cancers for CD patients, in particular lung cancers, and of biliary tract cancer and lymphoma for UC patients.

Conclusions: After 30 years of follow up, overall mortality rates were similar in IBSEN study patients and their matched controls despite higher mortality due to cardiovascular diseases and infections.
For CD patients only, we found that male sex, elderly onset, penetrating disease and colonic disease were associated with increased mortality.