New surgery and hospital-diagnosed infections in elderly patients with inflammatory bowel disease undergoing surgery - a nationwide cohort study

Background Elderly patients with inflammatory bowel disease (IBD) are fragile in many aspects. Therefore, in these patients, we studied post-operative complications (new abdominal surgery and serious infections after the first IBD surgery). Methods This is a nationwide cohort study based on Danish health registries and included patients with IBD undergoing surgery. The study population was split into ulcerative colitis (UC) and Crohn’s disease (CD). The exposed cohort (elderly) constituted those at an age of ≥ 60 years at first IBD surgery, and the unexposed (adults) those with surgery at the age of 18-59 years. We estimated adjusted Hazard Ratios (aHR) of a) new abdominal surgery within 2 years, and b) serious (hospital-diagnosed) infections within 6 and 12 months. We adjusted for several confounders including type of index surgery (laparoscopic or open). Results The aHR for a new surgery among elderly with UC and CD were 0.69 (95% CI 0.58-0.83) and 0.98 (95% CI 0.83-1.15), respectively. In elderly with UC, the aHRs of infections within 6 and 12 months after surgery were 1.07 (95% CI 0.81- 1.40) and 0.85 (95% CI 0.67-1.08), respectively. In the elderly with CD, the aHRs of infections within 6 and 12 months were 1.45 (95% CI 1.12-1.88) and 1.26 (95% CI 1.00-1.59), respectively. Conclusion The elderly with IBD did not have an increased risk of new abdominal surgery within two years of the first surgery. Elderly with CD, but not UC, had an increased risk of serious infections within 6 months of surgery.