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Am Fam Physician. 2020;101(4):248

Clinical Question

What factors and outcomes are associated with inappropriate treatment of asymptomatic bacteriuria?

Bottom Line

Inappropriate treatment of asymptomatic bacteriuria is common in hospitalized patients. Older patients, those with dementia or acutely altered mental status, and those with abnormal urinalysis results are more likely to be treated with antibiotics. Treatment did not improve clinical outcomes and was associated with a longer hospital stay. (Level of Evidence = 2b)


Using data from the Michigan Hospital Medicine Safety Consortium, the investigators identified 2,733 hospitalized patients with asymptomatic bacteriuria, defined as a positive urine culture without signs or symptoms of a urinary tract infection (UTI), such as dysuria, urinary frequency or urgency, suprapubic pain, fever, costovertebral pain or tenderness, hematuria, and autonomic dysreflexia/spasticity in patients with spinal cord injury. Patients with altered mental status but no other signs or symptoms of UTI and no evidence of systemic infection were categorized as having asymptomatic bacteriuria. The presence of UTI or asymptomatic bacteriuria was based on chart review and thus potentially flawed. (The quality of documentation may have varied.) The median age of the cohort was 77 years, almost 80% were women, and 83% were treated with antibiotics for a median of seven days. After multivariable analysis, factors associated with treatment of asymptomatic bacteriuria included older age, dementia, urinary incontinence, altered mental status, urine culture with Escherichia coli, leukocytosis, bacteriuria greater than 100,000 colony-forming units, and a positive urinalysis (defined as the presence of leukocyte esterase or nitrite, or more than five white blood cells per high-power field). When comparing patients with asymptomatic bacteriuria who received antibiotics and those who did not, there were no differences in 30-day mortality, readmissions, emergency department visits, discharge to post–acute care facility, or Clostridioides difficile infection. Those who received antibiotic treatment had a 37% increase in the length of hospital stay (four days vs. three days; relative risk = 1.37; 95% CI, 1.28 to 1.47).

Study design: Cohort (retrospective)

Funding source: Industry

Allocation: Uncertain

Setting: Inpatient (ward only)

Reference: Petty LA, Vaughn VM, Flanders SA, et al. Risk factors and outcomes associated with treatment of asymptomatic bacteriuria in hospitalized patients [published online August 26, 2019]. JAMA Intern Med.

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