Mortality and causes of death in patients with inflammatory bowel disease: a nationwide register study in Finland

Background and aim: Increased mortality has been reported in Crohn's disease (CD) but mostly not in ulcerative colitis (UC). We evaluated the overall and cause-specific mortality in a nationwide cohort of patients with inflammatory bowel disease (IBD) in Finland.

Methods: A total of 21,964 patients with IBD (16,649 with UC and 5315 with CD) from the Special Reimbursement register were diagnosed 1987-1993 and 2000-2007 and followed up to the end of 2010 by collating these figures with the national computerized Cause-of-Death Register of Statistics Finland. In each cause-of-death category, the number of deaths reported was compared to that expected in general population, and expressed as a standardized mortality ratio (SMR).

Results: Overall mortality was increased among patients with CD (SMR 1.33, 95% confidence interval 1.21-1.46) and UC (1.10, 1.05-1.15). SMR was significantly increased for gastrointestinal causes in CD (6.53, 4.91-8.52) and UC (2.81, 2.32-3.34). Patients with UC were found also to have increased SMR from pulmonary (1.24, 1.02-1.46) and cardiovascular disease (1.14, 1.06-1.22) and cancers of the colon (1.90, 1.38-2.55), rectum (1.79, 1.14-2.69) and biliary tract (5.65, 3.54-8.54), whereas SMR from alcohol-related deaths was decreased (0.54, 0.39-0.71). Patients with CD had a significantly increased SMR for pulmonary diseases (2.01, 1.39-2.80), infections (4.27, 2.13-7.63) and cancers of the biliary tract (4.51, 1.23-11.5) and lymphoid and hematopoietic tissue (2.95, 1.85-4.45).

Conclusions: In this Finnish nationwide study increased overall mortality in both CD and UC was observed. The excess mortality of 14% in IBD is mainly due to deaths related to inflammation in the gut.