Hospitalized patients often receive antibiotics for asymptomatic bacteriuria, which can lead to adverse events and antibiotic resistance. A quality improvement study sought to determine the effect of diagnostic stewardship (avoiding unnecessary urine cultures) versus antibiotic stewardship (avoiding or stopping unnecessary antibiotic use after an unnecessary culture) on reducing antibiotic treatment for asymptomatic bacteriuria.

Patients who were hospitalized, had a positive urine culture, and hadn't received antibiotic treatment for another infection were eligible for the study. A total of 14,572 patients from 46 hospitals were included, of whom 4,134 (28.4%) had asymptomatic bacteriuria. Of these patients, 3,175 (76.8%) received antibiotics.

During the three-year study period, antibiotic use related to asymptomatic bacteriuria declined from 29.1% to 17.1%. The percentage of patients with a positive urine culture who had asymptomatic bacteriuria (the diagnostic stewardship metric) decreased from 34.1% to 22.5%. By contrast, the percentage of patients with asymptomatic bacteriuria who received antibiotics (the antibiotic stewardship metric) remained stable during the study period (82% versus 76.3%). The mean duration of antibiotic treatment for asymptomatic bacteriuria declined only slightly, from 6.38 days to 5.93 days.

These results suggest that diagnostic stewardship may improve antibiotic use for asymptomatic bacteriuria more than antibiotic stewardship. The authors note that although they were unable to determine which specific diagnostic stewardship strategy was the most effective, national policy and antibiotic stewardship programs should consider requiring and incorporating diagnostic stewardship into improvement efforts.