Presentation (CTI)

OBJECTIVES: Various guidelines prefer molecular methods for diagnosing influenza, SARS-CoV-2, and RSV due to the limitations of antigen testing in sensitivity. We aimed to use real-world evidence to test whether these guidelines have been implemented and to assess the clinical utility of rapid PCR testing for influenza-like illness (ILI) in hospital emergency department compared to antigen testing.
METHODS: Analysis was done on Real-world EHR data in Truveta Studio. Patients who had either an Antigen or PCR test for either RSV, COVID-19 or Flu A/B in a hospital setting and had a diagnosis of ILI were selected for analysis. The dates for this analysis included any Antigen or PCR tests within the 2023-2025. Positivity rates for the tests are reported, as well as additional ILI testing, chest x-ray imaging, antiviral use and antibiotic use in those with both positive and negative results.
RESULTS: We analyzed a total of 79,058 patients who had either an antigen or PCR test for RSV, COVID-19, or Flu A/B, of which 22,284 (28.2%) had an antigen or PCR test in hospital emergency setting. Most patients had a PCR test (PCR = 21,349, 95.8%; antigen = 935, 4.2%). Positivity rates were higher for antigen than for PCR for all viruses tested (RSV: antigen 2.7%, PCR 1.5%; COVID-19: antigen 5.7%, PCR 1.1%; Flu A/B: antigen 10%, PCR 1.0%). Patients receiving rapid PCR testing had lower rates of antibiotic use at 14 days, regardless of the virus tested for and whether the test result was positive.
CONCLUSIONS: This analysis demonstrates that rapid molecular testing may result in better outcomes compared to antigen testing among patients evaluated in hospital emergency department. This supports existing recommendations. Further research is warranted to assess additional outcomes and comparison of the existing cohort with propensity score matching or multivariate models to address potential confounding and biases.