P112. The natural history of Crohn's disease (CD): A long-term (>10 years) follow-up study
F. Casals-Seoane1, J.P. Gisbert1, M. Chaparro1
1Hospital Universitario de La Princesa, IP, Gastroenterology and CIBEREHD, Madrid, Spain
Background: Most of the studies on the natural history of CD include small cohorts with less than 5 years of follow-up.
Aims: To study the natural history of CD in a cohort with more than 10 years of evolution. To identify predictive factors of bad outcome.
Methods: A retrospective study including CD patients with more than 10 years of evolution was performed. The study population was divided into 3 groups by year of diagnosis (Group A = 19851991, Group B = 19921997, Group C = 19982001). Survival curves were compared with the KaplanMeier test. Cox regression analysis was performed to identify predictive factors of surgery in these patients.
Results: 133 patients with CD were included. Mean follow-up was 17 years (range 351). 29% presented changes in disease behaviour. At baseline, the proportion of patients with stricturing behaviour was 11%, while 9% had penetrating behaviour. At the end of follow-up, these figures were 23% and 24% respectively. 43% of these changes occurred within the first 5 years of follow-up. There was an increasing and earlier use of thiopurines over time: 10 years after diagnosis the proportion of patients on thiopurines was 40% in group A, 59% in group B, and 82% in group C (p < 0.001), and the median time to start of thiopurines was 130, 83 and 39 months respectively.
Cumulative probability of intestinal surgery showed a small reduction over time: at 5 years after diagnosis it was 36% in group A, 28% in group B, and 25% in group C. 10 years after diagnosis these percentages were 47%, 41% and 35% respectively. Diagnosis between 1985 and 1991 (HR = 3.1; 95%CI = 1.56.3, p < 0.01), stricturing behaviour (HR = 3.7; 95%CI = 1.68.3, p < 0.001), penetrating behaviour (HR = 9.3; 95%CI = 4.120.8, p < 0.001) and perianal disease (HR = 2.9; 95%CI = 1.65.2, p < 0.001) were all associated with a higher risk of intestinal surgery.
Conclusions: In a significant proportion of patients, CD modified its behaviour to more severe forms during the follow-up. Overall and early use of thiopurines have markedly increased over the past 15 years. Stricturing or penetrating behaviour, diagnosis between 19851991 and perianal disease increased the risk of intestinal surgery.