Nearly half of inpatients with pneumonia or urinary tract infection were overprescribed antibiotics after discharge

Nearly half of hospitalized patients treated for pneumonia or urinary tract infection (UTI) had antibiotic overuse after discharge, although overuse varied widely across hospitals, a recent study found.

Researchers looked at a cohort of non-critically ill hospitalized patients who received antibiotic therapy for pneumonia or UTI between July 1, 2017, and July 30, 2019, at 46 Michigan hospitals participating in the Michigan Hospital Medicine Safety Consortium, which has collected data on patients treated for these infections. The primary outcome was the percentage of patients discharged with antibiotic overuse, defined as unnecessary antibiotic use, excess antibiotic duration, or suboptimal fluoroquinolone use. When evidence for appropriate treatment was conflicting, treatment was considered appropriate. Results were published online on Sept. 11 by Clinical Infectious Diseases.

Of 21,825 patients treated for infection (n=12,445 pneumonia; n=9,380 UTI), 15,803 (72.4%) were prescribed an antibiotic at discharge, most commonly a fluoroquinolone (34.2%). Overall, 10,709 (49.1%) patients had antibiotic overuse after discharge (56.9% pneumonia; 38.7% UTI). The mean duration of antibiotic overuse after discharge was four days (interquartile range, 2 to 6). In patients treated for pneumonia, 63.1% of overuse days after discharge were due to excess antibiotic duration (19.5% suboptimal use of fluoroquinolones; 17.4% unnecessary therapy). In patients treated for UTI, 43.9% of antibiotic overuse days were due to unnecessary treatment of asymptomatic bacteriuria (37.3% excessive therapy; 18.7% suboptimal use of fluoroquinolones). Overall, the majority of fluoroquinolone overuse after discharge was due to a combination of unnecessary and excessive therapy rather than suboptimal use of fluoroquinolones. The percentage of patients discharged with antibiotic overuse varied fivefold among hospitals, from 15.9% (95% CI, 8.7% to 24.6%) to 80.6% (95% CI, 69.4% to 88.1%).

Limitations of the study include its observational design and the difficulty of defining and quantifying antibiotic overuse, the authors noted. They added that the results likely underestimated overuse because they focused on fluoroquinolones rather than including all potential types of suboptimal antibiotic therapy (e.g., prescribing broad-spectrum antibiotics when narrow therapy would suffice).

“Given the ubiquity of overuse after discharge it is imperative that stewardship programs enact interventions to improve prescribing—which often means stopping antibiotics—at care transitions. … Currently, however, discharge prescriptions are difficult for hospitals to monitor as they are often filled by external pharmacies and are not easy to count electronically,” they wrote.