Colonoscopy-related adverse events and mortality in an Italian organized colorectal cancer screening program

Background Post-colonoscopy adverse events are a key quality indicator in population-based colorectal cancer screening programs, and affect safety and costs. This study aimed to assess colonoscopy-related adverse events and mortality in a screening setting. Methods We retrieved data from patients undergoing colonoscopy within a screening program (fecal immunochemical test every 2 years, 50-69-year-olds, or post-polypectomy surveillance) in Italy between 2002 and 2014, to assess the rate of post-colonoscopy adverse events and mortality. Any admission within 30 days of screening colonoscopy was reviewed to capture possible events. Mortality registries were also matched with endoscopy databases to investigate 30-day post-colonoscopy mortality. Association of each outcome with patient-/procedure-related variables was assessed using multivariable analysis. Results Overall, 117881 screening colonoscopies (66584, 56.5%, with polypectomy) were included. Overall, 497 (0.42%) post-colonoscopy adverse events occurred: 281 (0.24%) bleedings (3.69/0.68 parts per thousand, operative/diagnostic procedures) and 65 (0.06%) perforations (0.75 parts per thousand /0.29 parts per thousand, respectively). At multivariable analysis, bleeding was associated with polyp size (>= 20 mm: odds ratio [OR] 16.29, 95% confidence interval [CI] 9.38-28.29), proximal location (OR 1.46, 95%CI 1.14-1.87), and histology severity (high risk adenoma: OR 5.6, 95%CI 2.43-12.91), while perforation was associated with endoscopic resection (OR 2.91, 95%CI 1.62-5.22), polyp size (OR 4.34, 95%CI 1.46-12.92), and proximal location (OR 1.94, 95%CI 1.12-3.37). Post-colonoscopy mortality occurred in 15/117881 cases (1.27/10000 colonoscopies). Conclusions In an organized screening program, post-colonoscopy adverse events were rare but not negligible. The most frequent event was post-polypectomy bleeding, especially after resection of large (>= 20mm) and proximal lesions.

Automated summary

In an organized screening program in Italy, post-colonoscopy adverse events were rare but not negligible. The most frequent event was post-polypectomy bleeding, especially after resection of large (>= 20mm) and proximal lesions.