Institutional antibiograms guide Emergency Department (ED) clinicians' empiric antibiotic selection. For this study, we created and compared antibiograms of ED patients stratified by disposition (admitted or discharged).Methods:
We conducted a cross-sectional study at two hospitals for 2014, comparing antibiograms limited to Escherichia coli urinary tract infections. Study-Specific Antibiograms, created for the study, excluded polymicrobial samples and multiple cultures from the same patient. Study-Specific Antibiograms were arranged by patient disposition: admitted (IP-Only) vs discharged from the ED (ED-Only). Antibiogram data were presented as average antibiotic sensitivities with 95% confidence intervals and demographic data as medians with interquartile ranges. Sensitivities between Study-Specific Antibiograms were compared by Fisher's Exact Test, alpha = 0.05, 2 tails.Results:
For Hospital A, 13 antibiotics were compared between Study-Specific ED-Only (n = 313) vs IP-Only (n = 244). We found that sensitivities to all four antibiotics appropriate for empiric outpatient therapy by Infectious Disease Society of America guidelines were significantly (p < 0.0001) higher in the ED-Only compared to IP-Only groups: ciprofloxacin 80% (76–90%) vs 60% (53–69%), levofloxacin 81% (77–91%) vs 63% (57–72%), nitrofurantoin 75% (70–84%) vs 51% (44–58%), and trimethoprim/sulfamethoxazole 73% (68–82%) vs 58% (52–67%). For Hospital B, 14 antibiotics were compared between Study-Specific ED-Only (n = 256) and IP-Only (n = 168). Two out of the five appropriate empiric outpatient antibiotics had significantly (p < 0.0001) higher sensitivities for ED-Only compared to IP-Only: ciprofloxacin 87% (83–91%) vs 71% (64–78%) and levofloxacin 86% (82–91%) vs 71% (65–78%).Conclusions:
We found higher antibiotic sensitivities in ED-Only than the IP-Only Study-Specific Antibiograms. Our Study-Specific Antibiograms offer an alternative guide for antibiotic selection in the ED.