Quality Improvement Interventions and Surgical Antimicrobial Prophylaxis

Abstract and Commentary

By Dean L. Winslow, MD, FACP, FIDSA, Chief, Division of AIDS Medicine, Santa Clara Valley Medical Center; Clinical Professor, Stanford University School of Medicine, is Associate Editor for Infectious Disease Alert

Synopsis: Forty-four acute care hospitals participated in a prospective study over four years to determine the effect of quality improvement (QI) interventions on appropriate prescribing of surgical antimicrobial prophylaxis. Hospitals were randomly assigned to either feedback on the results of the ongoing audit vs feedback plus an intensive collaborative intervention group. Both groups showed improvement in most quality indicators, but there appeared to be no benefit of the intensive QI collaborative intervention over performance feedback.

Source: Kritchevsky SB, et al. The effect of a quality improvement collaborative to improve antimicrobial prophylaxis in surgical patients, a randomized trial. Ann Int Med. 2008;149:472-481.

In this study, 44 acute care hospitals each randomly sampled 100 surgical cases (cardiac, hip, or knee replacement, hysterectomy) at both baseline and during the remeasurement phase of the study. All hospitals received a comparative feedback report. Twenty-two hospitals were randomly assigned to the intervention group where each hospital held two in-person meetings led by experts, and monthly teleconferences, and supplemental, educational materials were distributed. The quality parameter used as the primary outcome measure was the receipt of one dose of antibiotics within 60 minutes of surgery (120 minutes for vancomycin), with secondary outcomes of change in proportion of patients receiving any antibiotics, administration of antibiotics for 24 hours or less, administration of an appropriate antibiotic, and receipt of a single, preoperative dose plus any of the other five measures.

In the intervention group, 76.3% of patients received appropriately timed preoperative antibiotics at baseline, and 83.2% at remeasure. In the feedback-only group, the numbers were 74.8% at baseline and 85.3% at follow-up. Of those in the intervention group, the baseline and follow-up values for receipt of prophylaxis were 97.4% and 98.9%, respectively, with nearly identical values for the feedback-only group. Appropriate duration of antibiotics increased from 51.3% to 69.5% in the intervention group, with similar change seen in the feedback-only group. Appropriate antibiotic selection was high at baseline (93.8%) and did not change significantly in either the intervention or feedback groups. Interestingly, the proportion of patients who received a single preoperative dose decreased slightly from 85.1% to 80.2% in the intervention group but did not change in the feedback-only group.


Antimicrobial prophylaxis in the setting of surgery represents a significant proportion of the use of antibiotics in the United States and contributes to the cost of care. Inappropriate administration of antimicrobial prophylaxis has been shown to result in reduced prophylactic efficacy as well as excessive costs and potential selection of antibiotic-resistant organisms when prophylaxis is given for an excessive duration. While this study did not show any incremental benefit of intensive collaborative QI interventions, the good news is that it demonstrated that appropriately communicated feedback to prescribing providers did result in improvement of antimicrobial-prescribing practices in the surgical prophylaxis setting. It is likely that similarly conducted audits with communicated feedback could also be effective in improving antimicrobial prescribing for a variety of infections in both the inpatient and outpatient settings where guidelines exist.