P082 Survival over >20 years in a large Australian metropolitan cohort of inflammatory bowel disease patients: No excess overall mortality

Abstract

Background: Inflammatory Bowel Diseases (IBD) can be complicated by bowel cancer, perforation and toxic megacolon but it remains controversial whether this leads to excess mortality. There are few long term non-tertiary mortality studies on IBD but none from the Southern Hemisphere. Methods: A large Sydney based prevalence cohort (diagnosis year 1971 1992) of ambulatory IBD patients first described in 1995 was studied. Survival status and cause of death (COD) data were extracted from the Australian National Death Index. COD data were compared against the Australian Bureau of Statistics (year 2009) for general population mortality. Mortality figures were analysed using ‘relative survival’ (SURV2, Finnish Cancer Institute) for males (M) and females (F). Relationship between COD and IBD was agreed by consensus. Results: Of 818 cases (46.9% M; 373 CD, 403 UC, 42 IBD-U) 211 (25.8%) had died at the end of the study period. Median follow up was 22.7 years [M] and 22.2 years [F]. A definite or possible relation between IBD and COD was agreed in 23.7% (CD 27.9%, UC 21.1%). Relative survival for all IBD cases was no different to the general population at 10, 20 or 30 years except after 30 years when female CD deaths marginally exceeded controls. Digestive and cardiovascular deaths were over-represented in IBD but not overall malignant- or sepsis-related deaths. Cholangiocarcinoma was significantly increased in both UC and CD (P < 0.0001). Fatal colorectal cancer was increased in UC (Odds ratio 2.4, 95% CI = 1.05 5.5, P = 0.047). Conclusions: Overall survival is similar to that of the general population. For UC this finding is similar to Northern Hemisphere data, whilst the lack of increased mortality in CD is in contrast with Northern Hemisphere data. The integrated Australian health care system allowing longterm patient-specialist relationships may play a vital role in promoting overall health. A quarter of deaths were however directly related to IBD, but septic deaths were not increased. Whilst malignant deaths overall were not increased, cholangiocarcinoma and colorectal cancer deaths were increased.