Nearly half of older women diagnosed with a urinary tract infection (UTI) in an emergency department setting did not have confirmatory findings on urine culture and were given antibiotics inappropriately, a study found.
To determine how often older women presenting to an emergency department are diagnosed with a UTI without a positive urine culture and to whether the way urine is collected improves the accuracy of the urinalysis, researchers conducted a retrospective chart review of 153 women ages 70 and older in an academic-affiliated emergency department in Providence, R.I. from December 2008 to March 2010.
A confirmed UTI was defined as a positive urine culture, with microbial growth of 10,000 colony-forming units (CFU)/ mL or more for clean-catch specimens and 100 CFU/mL or more for newly inserted catheter specimens. Diagnosis of UTI was defined as the designation by an emergency department physician.
Results appeared in the Journal of the American Geriatrics Society.
Of 153 individuals with an emergency-department-diagnosed UTI, only 87 (57%) had confirmed cases according to culture. Of the remaining 66 with negative cultures, 63 (95%) were administered or prescribed antibiotics in the emergency department. Researchers noted that catheterization improved the accuracy of urinalysis when assessing older women for possible UTI (P=.02), with catheterization yielding a lower proportion of false-positive urinalysis (31%) than clean catch (48%).
Diagnosis of a UTI in the emergency department was not generally based upon having urinary symptoms. Only 18% of the older women diagnosed with UTI came to the emergency department with it as a chief complaint. Other common complaints included change in mental status and falls. Researchers noted that older women commonly have asymptomatic bacteriuria, which the Infectious Diseases Society of America and the American Medical Directors Association recommend should not be treated.
Researchers wrote that emergency department physicians "cannot rely exclusively on a positive UA or the presentation of urinary symptoms as a predictor of a positive culture result."