Sensitivity of urinary pathogens for patients discharged from the emergency department compared with the hospital...

Data for hospital antibiograms are typically compiled from all patients, regardless of disposition, demographics and other comorbidities.

We hypothesized that the sensitivity patterns for urinary pathogens would differ significantly from the hospital antibiogram in patients that were discharged from the emergency department (ED).

We evaluated a retrospective cohort of all adult patients with positive urine cultures treated in the 2016 calendar year at an inner-city academic ED. Positive urine cultures defined by our institution's microbiology department. Investigators conducted a structured review of an electronic medical record (EMR) to collect demographic, historical and microbiology records. We utilized a one-sample test of proportion to compare the sensitivity of each organism for discharged patients to the hospital published antibiogram. Alpha set at 0.05.

During the study period, 414 patients were discharged from the ED and found to have positive urine cultures; 20% age > 60 years old, 85% female, 79% Hispanic, 33% diabetic. The most common organisms was E. coli (78%). E. coli was sensitive to Trimethoprim-Sulfamethoxazole for 59% vs. 58% in our antibiogram (p = 0.77), Ciprofloxacin 81% vs. 69% (p < 0. 001), Nitrofurantoin 96% vs 95%; (p = 0.25). K. pneumoniae was sensitive to Trimethoprim-Sulfamethoxazole 87% vs. 80% in our antibiogram (p = 0.26), Ciprofloxacin 100% vs. 92% (p = 0.077), Nitrofurantoin 86% vs 41% (p < 0.001).

For our predominantly Hispanic study group with a high prevalence of diabetes, we found that our hospital antibiogram had relatively good value in guiding antibiotic therapy though for some organism/antibiotic combinations sensitivities were higher than expected.