Antibiotics continue to be overused in US hospitals, and the use of some, particularly broad spectrum agents, has increased significantly, according to a study in JAMA Internal Medicine.

James Baggs, PhD, from the CDC, and colleagues analyzed the records of patients who were discharged from about 300 US hospitals between January 1, 2006, and December 31, 2012. Data from more than 34 million discharges representing 166 million patient-days were included in the study.

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The researchers eliminated antibiotics not administered by oral, parental, or inhalation routes. Also, hospitals that did not submit any antibiotic usage data within a given year were eliminated from the analysis.

The investigators retrospectively estimated measures of antibiotic use as days of therapy per 1000 patient-days and the proportion of hospital discharges in which a patient received at least 1 dose of an antibiotic during his or her stay.

Overall, 55.1% of patients discharged received at least 1 dose of an antibiotic during their hospital visit. The overall rate of antibiotic use for all 7 study years was 755 per 1000 patient days. Usage of antibiotics was about 52% higher in critical care locations compared with noncritical care locations. Antibiotic usage varied by geographic location of the hospital. Divisions in the Southeast Central, Northeast Central, Southwest Central, and Mountain areas of the United States had the highest DOT per 1000 patient-days overall. Divisions in the New England, Mid Atlantic, and Pacific had the lowest.

Antibiotic usage varied by age group. Usage was lowest for those younger than 18 years and highest for those 45 years and older. The researchers noted that the data did not adequately represent children’s hospitals, which represent less than 1% of the hospitals included.

“While overall rates of antibiotic use in US hospitals did not change significantly from 2006 to 2012, we identified important trends within individual antibiotic classes,” stated Dr. Baggs and colleagues. “There were significant decreases in fluoroquinolones (20%) and first- and second-generation cephalosporins (7%) usage, but these decreases were offset by significant increases in vancomycin (32%) and agents with broad-spectrum activity against gram-negative bacteria, including carbapenem (37%), third- and fourth-generation cephalosporin (12%), and β-lactam/β-lactamase inhibitor combination antibiotics (26%). Despite substantial reduction in fluoroquinolone use, this class remained the most commonly used antibiotic class in US hospitals in 2012.”



  1. Baggs J, Fridkin SK, Pollack LA, Srinivasan A, Jernigan JA. Estimating national trends in inpatient antibiotic use among US hospitals from 2006 to 2012. JAMA Intern Med. September 19, 2016. doi:10.1001/jamainternmed.2016.5651