Clinical Utility of Broad-Range PCR Testing and Impact on Outcomes in Adults with Suspected Infection

Background: The development of broad-range polymerase chain reaction (BR-PCR) and next-generation sequencing techniques has significant implications for antimicrobial stewardship by increasing clinicians' ability to provide a tailored antimicrobial regimen. We sought to explore the clinical utility of BR-PCR testing and its impact on antimicrobial treatment among an adult cohort in a large hospital system. Methods: We retrospectively evaluated samples that underwent BR-PCR testing between 2017 and 2021 and summarized their clinical characteristics and impact on antimicrobial therapy. We identified BR-PCR testing as having clinical utility if the results led to adjustment of antimicrobial choice or duration or to confirmation of the initial empiric regimen, while no clinical utility was assigned to results that were negative or clinically insignificant, unavailable due to loss to follow-up, or lacking clinical indication (treatment completed before the test results returned or conventional cultures revealed the causative pathogen). Results: Among 359 specimens, BR-PCR was positive for 107 (30%). Clinical utility was identified for 106 (29.5%) specimens, including 45 with negative BR-PCR results. The rates of clinical utility varied based on the type of sample tested, with the highest clinical utility associated with cranial samples (60%), followed by body fluid (56%) and endovascular (54%) samples, and the lowest with CSF (15%) and bone and joint (19%) samples. We also identified many BR-PCR tests that were not clinically indicated (23.4%). Conclusions: This study highlights the utility of BR-PCR testing to support antimicrobial stewardship initiatives. Further studies are needed to identify clinical scenarios in which it is appropriate to order BR-PCR testing and for a careful interpretation of negative BR-PCR results.