Arvanitakis KD, Arvanitaki AD, Karkos CD, et al. - Risk of development of venous thromboembolism (VTE) was 2-fold elevated among patients suffering from inflammatory bowel disease (IBD), therefore, primary prophylaxis against VTE is extremely important.

• A systematic review and meta-analysis was conducted.

• Medline, Scopus, and the Cochrane Library of publications were explored.

• Eleven observational studies, with 3,175,012 IBD patients and 920,144,253 controls without IBD, were included.

• In IBD vs non-IBD persons, overall RR (relative risk) for VTE was 2.03.

• Lower VTE risk in IBD was revealed in studies with larger population size.

• A greater risk for VTE was reported in studies with a smaller population size.

• Moderately increased RR for VTE was noted after adjustment for smoking and body mass index.