Economic impact of redundant antimicrobial therapy in US hospitals

Overutilization of antimicrobial therapy places patients at risk for harm and contributes to antimicrobial resistance and escalating healthcare costs. Focusing on redundant or duplicate antimicrobial therapy is 1 recommended strategy to reduce overutilization and its attendant effects on patient safety and hospital costs.

This study explored the incidence and economic impact of potentially redundant antimicrobial therapy.

We conducted a retrospective analysis of inpatient administrative data drawn from 505 nonfederal US hospitals. All hospitalized patients discharged between January 1, 2008, and December 31, 2011, were eligible for study inclusion. Potentially redundant antimicrobial therapy was identified from pharmacy records and was defined as patients receiving treatment with overlapping antibiotic spectra for 2 or more consecutive days.

We found evidence of potentially inappropriate, redundant antimicrobial coverage for 23 different antimicrobial combinations in 394 of the 505 (78%) hospitals, representing a total of 32,507 cases. High-frequency redundancies were observed in 3 antianaerobic regimens, accounting for 22,701 (70%) of the cases. Of these, metronidazole and piperacillin-tazobactam accounted for 53% (n = 17,326) of all potentially redundant cases. Days of redundant therapy totaled 148,589, representing greater than $12 million in potentially avoidable healthcare costs.

Our study suggests that there may be pervasive use of redundant antimicrobial therapy within US hospitals. Appropriate use of antimicrobials may reduce the risk of harm to patients and lower healthcare costs.