Assessment of potential risk factors associated with ischaemic colitis.

Ischaemic colitis (IC) has been associated with a number of diverse disorders and risk factors, including irritable bowel syndrome (IBS) and constipation. We sought to assess, through a large-scale population study, the potential risk factors associated with IC. Patients with IC and matched controls without IC were identified using the medical and pharmacy claims data from the HealthCore Managed Care Database from 1st January 2000 to 31st May 2005. A multivariate conditional logistic regression model was developed to identify significant risk factors of IC. Interactions of age, sex, prior IBS diagnosis, and prior constipation diagnosis were further evaluated. We identified 1754 patients with IC and 6970 non-IC controls; 64% were women, and mean ages were 63 and 62 years respectively. The final parsimonious model comprised 19 independent variables associated with increased risk for IC including shock, dysentery, bloating, IBS, colon carcinoma, constipation, cardiovascular disease, dyspepsia, abdominal, aortic, or cardiovascular surgery, 12-month laxative, H-2 receptor blocker and oral contraceptive use. A significant interaction was observed between age and prior IBS on risk for IC. In conclusion, multiple risk factors for IC were identified and we confirmed that patients with IBS or constipation are at greater risk for IC.