TABLE 4.

Analysis of risk factors for BC^a

Analysis type and risk factor	Hazard ratio	95% confidence interval	P value
Univariate analysis
Pretransplant factors
Male sex	1.63	0.64–4.17	0.31
Age ≥ 60 yr	0.91	0.37–2.24	0.84
Diagnosis
Myeloid malignancy	1.73	0.40–7.41	0.46
Nonmyeloid malignancy	1 (reference)
Underlying diabetes mellitus	1.08	0.25–4.64	0.91
Disease risk
High risk	1.7	0.40–7.41	0.46
Standard risk	1 (reference)
Transplant type
CBT	2.01	0.68–5.93	0.21
Non-CBT	1 (reference)
Pretransplant status (until day 0)
LSNP (≥5 days)	2.97	1.27–6.96	0.01
Longer AMA exposure (≥30 days)	1.9	0.82–4.39	0.13
Longer AFA exposure (≥60 days)	1.4	0.57–3.44	0.46
PH-allo-HSCT	1.63	0.64–4.16	0.31
RIC	1.27	0.53–3.03	0.59
Antimicrobial regimen at day 0
Quinolone based	0.49	0.20–1.17	0.11
APBL based	1 (reference)
Antifungal regimen at day 0
Micafungin	1.44	0.59–3.5	0.42
Other antifungal agents	1 (reference)
Time-dependent factors
Systemic steroid administration	3.83	1.31–11.1	0.01
Engraftment within 30 days	0.54	0.16–1.84	0.32
aGVHD of grade 2 or greater	0.99	0.35–2.79	0.99
aGVHD of less than grade 2	1 (reference)
Diarrhea	1.87	0.68–5.12	0.22
Episode of antimicrobial agent change	1.91	0.35–10.5	0.46
Episode of antifungal agent change	0.93	0.35–2.51	0.89
Multivariate analysis
Systemic steroid administration	3.65	1.27–10.5	0.016
LSNP (≥5 days)	2.87	1.23–6.73	0.015
Longer AMA exposure (≥30days)	1.41	0.59–3.37	0.44
Quinolone based	0.73	0.29–1.84	0.5

^aCBT, cord blood transplantation; AMA, antimicrobial agent; AFA, antifungal agent; PH-allo-HSCT, history of allogeneic hematopoietic stem cell transplantation; RIC, reduced-intensity conditioning; APBL, antipseudomonal beta-lactam; aGVHD, acute graft-versus-host disease. Myeloid malignancy consists of acute myeloid leukemia, myelodysplastic syndrome, myelodysplastic syndrome with overt acute myeloid leukemia, and chronic myelogenous leukemia. The longer severe neutropenic phase until day 0 (LSNP) was defined as a severe neutropenic duration until day 0 (the first day of transplantation) of ≥5 days. Longer antimicrobial agent exposure means that the recipient received any antimicrobial agent continuously for ≥30 days until day 0 (the first day of transplantation). Longer antifungal agent exposure means that the recipient received any antifungal agent continuously for ≥60 days until day 0 (the first day of transplantation). Recipients with a history of allogeneic hematopoietic stem cell transplantation had received allogeneic hematopoietic stem cell transplantation 2 or more times. Diarrhea was defined as an increase in the number of stools to ≥7 stools per day over the baseline number during allo-HSCT. An episode of antimicrobial agent change means that the antimicrobial regimen that was administered at day 0 was changed to another antimicrobial regimen after the start of allo-HSCT; e.g., a quinolone-based regimen at day 0 was changed to an antipseudomonal beta-lactam-based regimen, an antipseudomonal beta-lactam-based regimen (e.g., a cefepime-based regimen) at day 0 was changed to another antipseudomonal beta-lactam-based regimen (e.g., a meropenem-based regimen), an anti-methicillin-resistant Staphylococcus aureus agent was added to the regimen, and/or amikacin was added to the regimen. An episode of an antifungal agent change means that the antifungal regimen that was administered at day 0 was changed to another antifungal regimen after the start of allo-HSCT.