Implementation of an evidence- based algorithm reduces blood culture overuse in an adult emergency department

Abstract

Objectives: Blood cultures are an essential tool in the accurate diagnosis of bacteremia, but are often overused in low-risk patients. The inappropriate ordering of blood cultures risks exposing patients to prolonged unnecessary courses of antibiotics and increases treatment costs. In our Adult Emergency Department (AED), an evidence-based algorithm was developed to guide blood culture ordering based on a validated clinical decision rule (Shapiro Rule). The primary goal of this study was to assess the effects of this algorithm on rate of blood culture collection in the AED. Methods: This study is a retrospective observational study pre and post intervention. Laboratory data were used to track rates of blood culture ordering and contamination before and after the implementation of the blood culture ordering algorithm. A clinical decision support tool was also implemented into our electronic medical record (EMR) to remind providers of the ordering criteria and to track the reasons for which blood cultures were being performed. These responses were extracted from the EMR and analyzed using descriptive statistics. Results: After implementation of the algorithm, we observed a 33.5% decrease in the mean monthly blood cultures ordered from the AED. This result was statistically significant with a p-value of <0.001. Over the same time period, there was no significant change in blood culture contamination rates. No adverse patient outcomes were attributed to use of the algorithm. The most common reason providers cited when ordering a blood culture was the presence of an immune compromising condition, followed by the Shapiro rule criteria and provider discretion. Conclusions: This study demonstrates that evidence-based institutional protocols can be implemented quickly and be efficacious in preventing unnecessary blood culture testing, thereby reducing costs of care. The utilization of an interdisciplinary approach and effective incorporation of information technology are key components in ensuring initial success and sustainability over time.