Characteristics of Patients, Biospecimen Group (N = 94)a.

aCharacteristics of patients in the observational group (N = 1144) can be found in Table S1.bEngraftment was defined as an absolute neutrophil count greater than 500 cells/µL for three consecutive days.cAssessed during inpatient allo-HSCT hospitalization, from beginning of pre-transplant up to 35 days post-transplant.dAntibiotics are not mutually exclusive categories and thus does not sum to 100%.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.gReported as median, with range in parentheses.