Treatment of Positive Urine Cultures in Hospitalized Patients: A Driver of Antimicrobial Misuse

1Ann Arbor VAMC, Ann Arbor, MI
2University of Michigan, Ann Arbor, MI
3St. Joseph Mercy Hospital, Ann Arbor, MI

Meeting: Hospital Medicine 2012, April 1-4, San Diego, Calif.

Abstract number: 97602


Obtaining a urine culture in hospitalized patients is extremely common. Positive cultures frequently trigger antimicrobial therapy, but the appropriateness of this treatment remains unclear. We sought to describe physician management of positive urine cultures and the extent to which treatment contributes to antimicrobial overuse.


We randomly selected patients admitted to a large academic center between February 2008 and February 2009 who had positive urine cultures. Patients were excluded, if they were admitted to intensive care, had a major urinary procedure (e.g., renal transplant), were actively being treated for a urinary tract infection (UTI) at the time of admission or >48 h prior to urine collection. Two hospitalists performed retrospective medical record review to determine the presence of signs or symptoms of UTI, urinary catheter presence, antimicrobial therapy, reason for and duration of antimicrobials. Appropriateness criteria for diagnostic testing and antimicrobial treatment was defined using national and professional society guidelines (i.e., Centers for Disease Control and Prevention and Infectious Diseases Society of America) and final determination of appropriateness was adjudicated by the hospitalist reviewers and two infectious disease physicians.


Of 153 patients, 73 (48%) had an appropriate reason documented to obtain a urine culture. The most common reasons for obtaining a culture were fever (27%), altered mental status (16%) and change in character of urine (15%). A total of 94 (61%) had asymptomatic bacteriuria, including 39 patients (41%) on antimicrobials at the time the urine culture was sent. Despite the lack of signs or symptoms of UTI, 60 (64%) were treated for a UTI within 72 h of the urine culture, including 59 (98%) who were newly started on antimicrobials for treatment. Patients with asymptomatic bacteriuria received a mean of 6.6 days of antimicrobials. Of 59 patients (39%) who met criteria for UTI, 15 (25%) had a catheter associated UTI. Fifty–five (93%) were started on initial antimicrobials that were consistent with guidelines. The duration of therapy was incorrect for 16 patients (27%) including four patients treated an average 6 days beyond the recommended course and 12 patients with an insufficient duration of treatment. The most common reason for truncated therapy was inappropriate categorization of a patient as having an uncomplicated UTI.


In hospitalized patients, systemic symptoms were the most common drivers of orders for urinary culture. Over half of patients with positive urine cultures had asymptomatic bacteriuria. A majority of these patients inappropriately received antimicrobials. In patients meeting criteria for UTI, antimicrobial use was inappropriate in over one quarter. Strategies to promote appropriate diagnostic testing and treatment for possible UTI in hospitalized patients are urgently needed and will likely reduce antibiotic misuse. Hospitalists can help lead these improvement efforts.

To cite this abstract:

Malani A, Chenoweth C, Meddings J, Washer L, Kuhn L, Saint S, Hartley S, Flanders S, Valley S, Gandhi T. Treatment of Positive Urine Cultures in Hospitalized Patients: A Driver of Antimicrobial Misuse. Abstract published at Hospital Medicine 2012, April 1-4, San Diego, Calif. Abstract 97602. Journal of Hospital Medicine. 2012; 7 (suppl 2). Accessed March 28, 2020.

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