Risk factors for treatment of asymptomatic bacteriuria in a rural health system

Asymptomatic bacteriuria is often inappropriately treated, leading to antimicrobial-related adverse events and contributing to antimicrobial resistance. This study examined the asymptomatic bacteriuria treatment rate at a rural Wisconsin health system and the patient-specific factors that may be influencing clinicians' decisions to treat.

This is a retrospective descriptive report of patients admitted from January to May 2022 at 7 rural Wisconsin hospitals. Patients were included if they were a hospitalized adult with asymptomatic bacteriuria. Patients were excluded if they had a urinary tract abnormality, active infection, symptoms of a urinary tract infection, a planned urological surgery, or treatment or prophylaxis for a urinary tract infection within 72 hours of admission, were immunocompromised, or were transferred from an outside facility. Electronic and manual chart abstraction were used for data collection.

Of 429 patients with a positive urine culture, 137 patients with asymptomatic bacteriuria were included in the study. The median age was 75 years, and most patients were female (80.3%). The treatment rate of asymptomatic bacteriuria was 78.1%, amounting to 393 days of unnecessary antimicrobial therapy. Symptoms of fatigue (P = 0.014) and altered mentation (P < 0.006) and urinalysis results of nitrite positivity (P = 0.026) and pyuria (P < 0.001) were each independently associated with antimicrobial treatment.

Despite guideline recommendations to avoid treatment of asymptomatic bacteriuria, treatment rates in rural hospitalized patients remain high. Nonspecific signs and symptoms of altered mentation and fatigue as well as laboratory findings of nitrite positivity and pyuria were factors associated with a decision to treat. Future stewardship efforts should speak to the poor specificity of these factors.