Early antibiotic exposure and clinical outcomes following HCT. (A-B) The 100-day cumulative incidence of CMV reactivation (any viremia) by antibiotic use by day +14. Number of subjects in log-rank analysis was as follows: anaerobic coverage (n = 28); no anaerobic coverage (n = 74); and >4 (n = 14), 2-3 (n = 51), or 1 (n = 37) antibiotic. (C-D) The 100-day cumulative incidence of clinically significant CMV reactivation by antibiotic use by day +14. Number of subjects in log-rank analysis was as follows: anaerobic coverage (n = 40); no anaerobic coverage (n = 100); and >4 (n = 24), 2-3 (n = 66), or 1 (n = 50) antibiotic. (E-F) One-year cumulative incidence of all-cause mortality by antibiotic use by day +14. Number of subjects in log-rank analysis was as follows: anaerobic coverage (n = 48); no anaerobic coverage (n = 101); >4 (n = 31), 2-3 (n = 67), or 1 (n = 51) antibiotics. (G-H) One-year cumulative incidence of nonrelapse mortality by antibiotic use by day +14. Number of subjects in log-rank analysis was as follows: anaerobic coverage (n = 48); no anaerobic coverage (n = 101); >4 (n = 31), 2-3 (n = 67) or 1 (n = 51) antibiotics. Insert corresponds to hazard ratios estimated by using Cox regression. Anaerobic coverage exposure includes metronidazole, clindamycin, meropenem, and piperacillin-tazobactam.