Supplementary Material for: Drug Exposure and Risk of Microscopic Colitis: A Systematic Review and Meta-analysis

Background and objectives: Microscopic Colitis (MC) is a chronic inflammatory bowel disease, characterized by watery diarrhoea, normal radiological and endoscopic appearance. Concern regarding a potential association between drug exposure and MC has recently emerged. We sought to systematically review and summarize the evidence for the potential association. Methods: A systematic review and meta-analysis were performed to evaluate the incidence of MC associated with exposure to drug. The PubMed and Embase databases were searched to identify potential studies for inclusion. Results: Twelve case-control studies were included in the meta-analysis. The results showed exposure to NSAID (OR, 1.64; 95% CI 1.14-2.37; P<0.001), PPI (OR, 2.36; 95% CI 1.59-3.52; P<0.001), SSRI (OR, 2.16; 95% CI 1.5-3.13; P<0.001), or aspirin (OR, 2.84; 95% CI 1.4–5.76; P < 0.001) was related to the incidence of MC; however, such relationships in PPI and SSRI may be modulated by the selection of controls. Furthermore, we did not found a positive association with other drug exposure and MC. Conclusion: This meta-analysis indicated that NSAID, PPI, SSRI, or aspirin consumption may increase the risk for MC. Further studies exploring drug-induced microscopic colitis should include control groups with diarrhea, and not only healthy controls.