In multivariate analysis model 1, the SOFA score (adjusted odds ratio [aOR], 1.16; 95% CI, 1.11–1.20; P < 0.001), maximum WBC count (aOR, 1.01; 95% CI, 1.00–1.02; P < 0.001), minimum serum albumin (aOR, 0.65; 95% CI, 0.52–0.51; P < 0.001), and ventilator use (aOR, 5.49; 95% CI, 2.23–13.55; P < 0.001) were associated with severe CDI. This evidence concerns the gene ALB and clostridium difficile infection.