Risk Factors for Antibiotic Resistant Urinary Pathogens in Patients Discharged From the Emergency Department

Urinary tract infections (UTIs) are one of the most common indications for antimicrobial use in the emergency department (ED). Appropriate empiric selection is crucial to ensure optimal care while limiting broad-spectrum antibiotic use. The primary objective of this study was to evaluate the relationship between patient-specific risk factors and drug resistant urinary pathogens in patients discharged from the ED and followed by Emergency Medicine Pharmacists (EMPs). This was a single-center, retrospective chart review of adult (≥18 years old) patients with positive urine cultures discharged from the ED. The association between risk factors and pathogen resistance to ≥1 classes of antibiotics was evaluated using multivariate logistic regression. Risk factors included the following: hospitalization within the previous 30 days, intravenous antibiotic use within 90 days, diabetes, clinical atherosclerotic cardiovascular disease, psychiatric disorder, dementia, current antibiotic use for any indication, previous lifetime history of UTIs, indwelling or intermittent catheterization, hemodialysis, previous lifetime history of a urologic procedure, urinary tract abnormality, immunosuppressive disease or medications, current residence in a nursing or rehabilitation facility, and history of a multidrug resistant organism (MDRO). A total of 1018 patients were included. There was an increase in the odds of antibiotic resistance in patients with cystitis and ≥2 risk factors (Odds Ratio [OR] = 1.70, 95% CI = 1.24-2.32). In those with pyelonephritis, there was a non-significant increase in the odds of resistance for those with ≥2 risk factors (OR = 1.83, 95% CI = 0.98-3.42). Patients with pyelonephritis discharged on inappropriate antibiotics were more likely to return to the ED within 30 days ( = .03). For patients with cystitis discharged from the ED, those with ≥2 patient-specific risk factors had significantly increased odds of antibiotic resistance. Patients with pyelonephritis, but not cystitis, who were discharged on inappropriate antibiotics were more likely to return to the ED within 30 days. In conjunction with an EMP culture follow-up program, the identification of risk factors for antimicrobial resistance can be used to design more patient-specific empiric antibiotic selections.