Background and aims: Clostridium difficile infection (CDI) has been associated with an increased mortality risk among patients with inflammatory bowel disease (IBD) in multiple observational studies. We performed a systematic review and meta-analysis to help clearly define the magnitude of risk in IBD patients with and without CDI, and to assess the risk in individual IBD subtypes.
Methods: A systematic search of multiple electronic databases was conducted for observational studies reporting the risk of mortality in IBD, stratified by the presence of CDI. Weighted summary estimates were calculated using generalized inverse variance with random-effects model. Study quality was assessed using the Newcastle-Ottawa scale.
Results: Ten observational studies were identified (8 from North America and 2 from Europe) and included 40,700 IBD patients with CDI and 1,320,764 IBD controls without CDI. Overall, IBD patients with CDI had a higher risk of mortality compared with IBD patients without CDI [odds ratios (OR), 4.39; 95% confidence interval (CI), 3.56-5.42; I=93%]. The results were stable in high-quality studies and in hospitalized patients. When patients were stratified by IBD type, CDI was associated with increased mortality in patients with ulcerative colitis (7 studies) (OR, 4.39; 95% CI, 3.44-5.61; I), but not in patients with Crohn's disease (4 studies) (OR, 2.21; 95% CI, 0.84-5.77; I). Individual studies were limited by an inability to control for IBD disease activity and therapeutic interventions.
Conclusions: On the basis of 10 observational studies with at least moderate quality, CDI seems to increase mortality risk in IBD, particularly in ulcerative colitis. These findings are a cause for concern and suggest that CDI should be managed aggressively in patients with IBD.