Univariate predictors of CDI in the biospecimen group and observational group, by Cox proportional hazards regression.

aMultivariate analysis of the biospecimen group can be found in Table S2.bMultivariate analysis of the observational group can be found in Table S3.cAnalyzed as a time-varying predictor.dFluoroquinolones consist of ciprofloxacin and levofloxacin.eBeta-lactams include cephalosporins, beta-lactam/beta-lactamase combinations, and carbapenems.fPrior antibiotics refer to antibiotics given prior to allo-HSCT and prior to observation time, within 14 days, and were not analyzed as time-varying predictors.