Overtreatment of presumed urinary tract infection in older women presenting to the emergency department

Abstract

Objectives: To determine how often older women presenting to an emergency department (ED) are diagnosed with a urinary tract infection (UTI) without a positive urine culture and to investigate whether collecting urine by catheterization instead of clean catch improves the accuracy of the urinalysis (UA).

Design: Retrospective chart review.

Setting: Academic-affiliated ED in Providence, Rhode Island.

Participants: One hundred fifty-three women aged 70 and older with diagnosis of UTI in the ED between December 1, 2008, and March 1, 2010.

Measurements: Chief complaint, review of systems, results of UA and culture, urine procurement (clean catch, straight catheter, or newly inserted Foley catheter), antibiotic administered or prescribed, and diagnosis. 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; an ED diagnosis of UTI was defined as the designation by an ED physician.

Results: Of 153 individuals with an ED-diagnosed UTI, only 87 (57%) had confirmed UTI according to culture. Of the remaining 66 with negative cultures, 63 (95%) were administered or prescribed antibiotics in the ED. The method of urine procurement affected the ability of a UA to predict the culture result (P = .02), with catheterization yielding a lower proportion of false-positive UA (31%) than clean catch (48%).

Conclusion: Nearly half of older women diagnosed with a UTI in an ED setting did not have confirmatory findings on urine culture and were therefore inappropriately treated. Catheterization improved the accuracy of UA when assessing older women for possible UTI.