Analysis of Clostridium difficile infections after cardiac surgery: Epidemiologic and economic implications from national data

Objectives Clostridium difficile infections (CDIs) have increased during the past 2 decades, especially among cardiac surgical patients, who share many of the comorbidity risk factors for CDI. Our objectives were to use a large national database to identify the regional-, hospital-, patient-, and procedure-level risk factors for CDI; and determine mortality, resource usage, and cost of CDIs in cardiac surgery. Methods Using the Nationwide Inpatient Sample database, we identified 349,122 patients who had undergone coronary artery bypass, valve, or thoracic–aortic surgery from 2004 to 2008. Of these, 2581 (0.75%) had been diagnosed with CDI. Multivariable regression analysis and the propensity method were used for risk adjustment. Results Compared with the West, CDIs were more likely to occur in the Northeast (odds ratio [OR], 1.28; 95% confidence interval [CI], 1.12-1.47) and Midwest (OR, 1.27, 95% CI, 1.11-1.46) and less likely in the South (OR, 0.80; 95% CI, 0.70-0.90). Medium-size hospitals (OR, 0.88; 95% CI, 0.78-0.99) had a lower risk of CDI than did large hospitals. Older age (>75 years; OR, 2.59; 95% CI, 1.93-3.49), longer preoperative length of stay (OR, 1.51; 95% CI, 1.43-1.60), Medicare (OR, 1.21; 95% CI, 1.05-1.39) and Medicaid (OR, 1.60; 95% CI, 1.31-1.96) coverage, and more comorbidities were associated with CDI. Among the matched pairs, patients with CDIs had greater mortality (302 [12%] vs 187 [7.2%], P