Predictors of mortality among patients undergoing colectomy for ischemic colitis: a population-based, United States study

BACKGROUND: Ischemic colitis is a potentially life-threatening condition that can require colectomy for management.

OBJECTIVE: To assess independent predictors of mortality following colectomy for ischemic colitis using a nationally representative sample of hospitals in the United States.

METHODS: The Nationwide Inpatient Sample was used to identify all patients with a primary diagnosis of acute vascular insufficiency of the colon (International Classification of Diseases, Ninth Revision codes 557.0 and 557.9) who underwent a colectomy between 1993 and 2008. Incidence and mortality are described; multivariate logistic regression analysis was performed to determine predictors of mortality.

RESULTS: The incidence of colectomy for ischemic colitis was 1.43 cases (95% CI 1.40 cases to 1.47 cases) per 100,000. The incidence of colectomy for ischemic colitis increased by 3.1% per year (95% CI 2.3% to 3.9%) from 1993 to 2003, and stabilized thereafter. The postoperative mortality rate was 21.0% (95% CI 20.2% to 21.8%). After 1997, the mortality rate significantly decreased at an estimated annual rate of 4.5% (95% CI -6.3% to -2.7%). Mortality was associated with older age, 65 to 84 years (OR 5.45 [95% CI 2.91 to 10.22]) versus 18 to 34 years; health insurance, Medicaid (OR 1.69 [95% CI 1.29 to 2.21]) and Medicare (OR 1.33 [95% CI 1.12 to 1.58]) versus private health insurance; and comorbidities such as liver disease (OR 3.54 [95% CI 2.79 to 4.50]). Patients who underwent colonoscopy or sigmoidoscopy (OR 0.78 [95% CI 0.65 to 0.93]) had lower mortality.

CONCLUSIONS: Colectomy for ischemic colitis was associated with considerable mortality. The explanation for the stable incidence and decreasing mortality rates observed in the latter part of the present study should be explored in future studies.