Accelerate Diagnostics, Inc. announced the publication of its Improving Outcomes and Antibiotic Stewardship (IOAS) Study in the journal Clinical Infectious Diseases. The multi-center, real-world study compared data before and after implementation of the Accelerate Pheno system across several hospitals to determine its impact on the treatment of patients with bloodstream infections. The data showed statistically significant reductions in time to optimal antimicrobial therapy, modification, and de-escalations associated with widespread patient benefits. The study included endpoints for microbiology test turnaround time, antimicrobial use, hospital length of stay, and 30-day mortality. The data showed that using Accelerate Pheno system reduced time to optimal antimicrobial therapy by 17.2 hours (median, IQR), time to first antimicrobial modification by 10.3 hours (median, IQR), and antimicrobial de-escalation time by 8.8 hours (median, IQR). The value of early antimicrobial optimization is likely associated with widespread patient and societal benefits such as limiting the emergence of antimicrobial resistance and reducing harm from unnecessary antimicrobial exposures. In addition, there was a 1-day reduction in hospital length of stay for patients with Gram-negative bloodstream infections, which are increasingly resistant to antibiotics, in the post-Accelerate Pheno implementation group. Furthermore, within the group of patients who were initially on ineffective antimicrobial therapy, time to effective therapy was reduced by 6.6 hours (median, IQR) and there was a clinically significant reduction of 6.4% in the 30-day mortality rate in the post-Accelerate Pheno implementation group. These findings highlight that the effects of early identification and antimicrobial susceptibility testing for patients with bloodstream infections were substantial and widespread in this sizable multi-center study.