Sustained savings from a longitudinal cost analysis of an internet-based preapproval antimicrobial stewardship...

To evaluate an internet-based preapproval antimicrobial stewardship program for sustained reduction in antimicrobial prescribing and resulting cost savings.

Retrospective cohort study and cost analysis.

Review of all doses and charges of antimicrobials dispensed to patients over 6 years (July 1, 2005-June 30, 2011) at a tertiary care pediatric hospital.

Restricted antimicrobials account for 26% of total doses but 81% of total antimicrobial charges. Winter months (November-February) and the oncology and infant and toddler units were associated with the highest antimicrobial charges. Five restricted drugs accounted for the majority (54%) of charges but only 6% of doses. With an average approval rate of 91.5% (95% confidence interval [CI], 91.1%-91.9%), the preapproval antibiotic stewardship program saved $103,787 (95% CI, $98,583-$109,172) per year, or $14,156 (95% CI, $13,446-$14,890) per 1,000 patient-days.

A preapproval antimicrobial stewardship program effectively reduces the number of doses and subsequent charges due to restricted antimicrobials years after implementation. Hospitals with reduced resources for implementing postprescription review may benefit from a preapproval antimicrobial stewardship program. Targeting specific units, drugs, and seasons may optimize preapproval programs for additional cost savings.