Rapid Genomic Testing: A Study of Institutional Utilization and Outcomes.

Rapid genomic testing (rGT) is increasingly being used as a first-tier test for critically ill individuals. Limited outcome data make ensuring appropriate utilization challenging. This study evaluates ordering trends and factors impacting the diagnostic yield of rGT. A retrospective analysis was performed on rGT orders reviewed between 2020 and 2024. Diagnostic yield, turnaround time (TAT), and clinical status at the time of the result were ascertained through chart review. Of 270 rGT orders, 98% (265/270) were ordered inpatient, and 79% (213/270) were rapid genome sequencing. While rGT utilization increased more than tenfold in the study period, the diagnostic yield declined. The overall diagnostic yield in our cohort was 20% (54/270). Only 10% (27/265) of inpatient cases were both diagnostic and resulted while the individual was still hospitalized. In 2024, the mean laboratory TAT was reduced to 8.6 days (n = 135) from the 2020-2023 average of 12.5 days (n = 135, p < 0.0001). Increased uptake of rGT as a first-tier genetic test suggests a shift toward broad inpatient genetic testing and is associated with a lower diagnostic yield over time. Evidence-based laboratory stewardship should seek to balance expanded access to rGT while maintaining high clinical utility.