The clinical characteristics of patients with free perforation in Korean Crohn's disease: results from the CONNECT study

Background: Free perforation is the most severe and debilitating complication associated with Crohn's disease (CD), and it usually requires emergency surgery. The aim of this study was to evaluate the incidence of free perforation among Korean patients with CD. Methods: The CrOhn's disease cliNical NEtwork and CohorT (CONNECT) study was conducted nationwide in Korea, and patients who were diagnosed with CD between 1982 and 2008 were included in this retrospective study. We investigated the incidence of free perforation among these patients and their clinical characteristics. Results: A total of 1346 patients were analyzed and 88 patients (6.5%) were identified with free perforation in CD. The mean age of the free perforation group was 31.8 +/- 13.0 years, which was significantly higher than that of the non-perforated group (27.5 +/- 12.1 years) (p = 0.004). Free perforation was the presenting sign of CD in 46 patients (52%). Of the 94 perforations that were present in 88 patients, 81 involved the ileum. Multivariate logistic regression analysis determined that free perforation was significantly associated with being aged >= 30 years at diagnosis (OR 2.082, p = 0.002) and bowel strictures (OR 1.982, p = 0.004). The mortality rate in the free perforation group was significantly higher (4.5%) than that in the non-perforated group (0.6%) (p < 0.001). Conclusion: The incidence of free perforation in Korean patients with CD was 6.5%. Being aged >= 30 years at CD diagnosis and bowel strictures were significant risk factors associated with free perforation.