Antimicrobial Stewardship and Intensive Care Unit Mortality: A Systematic Review

Background. Antimicrobial stewardship programs (ASPs) using audit and feedback in the intensive care unit (ICU) setting can reduce harms related to inappropriate antibiotic use. However, inappropriate discontinuation or narrowing of antibiotic treatment could increase infection-related mortality in this population. Individual ASP studies are underpowered to detect differences in mortality. Methods. We conducted a systematic review and meta-analysis of audit and feedback in the ICU setting, using mortality as our outcome. Results. Of 2447 citations, 11 studies met our inclusion criteria. Although a variety of study designs were used to assess reductions in antibiotic use, mortality was analyzed using an uncontrolled before-after study design in all studies. Five studies directed audit and feedback to all or most ICU patients receiving antibiotics and measured overall ICU mortality. In the meta-analysis of these studies, the pooled relative risk of ICU mortality was 1.03 (95% confidence interval, .93-1.14). A second meta-analysis of 3 smaller studies that evaluated mortality only in patients directly assessed by the ASP found a pooled relative risk of ICU mortality of 1.06 (95% confidence interval, .80 to 1.4). Three studies were not appropriate for meta-analysis, but their results were consistent with our overall findings. Conclusions. Our systematic review did not identify a change in mortality associated with antimicrobial stewardship using audit and feedback in the ICU setting. These results increase our confidence that audit and feedback can be safely implemented in this setting. Future studies should report standardized estimates of mortality and use more robust study designs to assess mortality, when feasible.