Cause-specific mortality and 30-year relative survival of Crohn's disease and ulcerative colitis

Data from the northern hemisphere suggest that patients with ulcerative colitis (UC) have similar survival to the general population, whereas mortality in Crohn's disease (CD) is increased by up to 50%. There is a paucity of data from the southern hemisphere, especially in Australia.

A prevalence cohort (1977-1992) of patients with inflammatory bowel disease (IBD) diagnosed after 1970 was studied. Survival status data and causes of death up to December 2010 were extracted from the National Death Index. Relative survival analysis was carried out separately for men and women.

Of 816 cases (384 men, 432 women; 373 CD, 401 UC, 42 indeterminate colitis), 211 (25.9%) had died by December 2010. Median follow-up was 22.2 years. Relative survival of all patients with IBD was not significantly different from the general population at 10, 20, and 30 years of follow-up. Separate analyses of survival in CD and UC also showed no differences from the general population. There was no difference in survival between patients diagnosed earlier (1971-1979) or later (1980-1992). At least 17% of the deaths were caused by IBD. Fatal cholangiocarcinomas were more common in IBD (P < 0.001), and fatal colorectal cancers more common in UC (P = 0.047).

In Australia, IBD patient survival is similar to the general population. In contrast to data from Europe and North America, survival in CD is not diminished in Australia. IBD caused direct mortality in 17%, especially as biliary and colorectal cancers are significant causes of death.