# Impact of an Algorithm to Triage Patients Discharged From the Emergency Department With Blood Cultures Positive for Staphylococcus aureus or Coagulase-Negative Staphylococcus

## TL;DR

A new algorithm helps emergency department staff decide whether to recall patients after blood cultures test positive for Staphylococcus species.

## Contribution

The study introduces and evaluates an algorithm for triaging patients with post-discharge positive blood cultures for Staphylococcus species.

## Key findings

- The algorithm led to a 7.3% reduction in callback rates, though not statistically significant.
- Algorithm adherence was 84.6%, with minimal deviation in callback decisions.
- No infectious-related safety events occurred in patients deemed to have contaminants.

## Abstract

Blood cultures obtained in the emergency department (ED) may become positive after discharge. Healthcare professionals must determine if these results represent true infection or a likely contaminant. An institutional algorithm was developed to assist with healthcare professional response to positive blood cultures for S. aureus and coagulase-negative staphylococci (CoNS) in these situations.

We conducted a single system, multisite cohort study comparing before and after implementation of an ED decision-making algorithm from November 2022 to December 2023. Adults were included if they were discharged from the ED before blood cultures became positive for Staphylococcus species. The primary outcome was the difference in rates of patients called back to the ED pre- and postalgorithm implementation. Secondary endpoints evaluated algorithm adherence and safety.

A total of 253 patients, 188 pre- and 65 postimplementation, were enrolled. There was a 7.3% reduction in patients called back to the ED after algorithm implementation (95% CI [−21.1 to 6.3], P = .3). Algorithm adherence after implementation was 84.6% with a difference in actual and algorithm-based callback rates of 4.6%. After algorithm implementation, no patients deemed to have a contaminant experienced an infectious-related safety event.

This time-saving algorithm was well received by our ED professionals and served as a helpful tool in safely and effectively triaging patients who had positive blood cultures for Staphylococcus species after discharge to determine who should be called back for further evaluation. There was a nonstatistically significant but clinically meaningful reduction in callback rates. Postimplementation algorithm adherence was high, and the majority of callback decisions were appropriate.