Methods: We performed a multi-center prospective controlled trial at 4 US EDs. From November 2013 – April 2014 we enrolled adults who presented to the ED with an acute respiratory illness who would meet CDC criteria for antiviral treatment if influenza positive. The test sites (2 EDs) performed Xpert Flu testing on all enrolled participants and the result was given to the ED provider. The control sites (2 EDs) continued usual care with provider-directed influenza testing using either rapid antigen tests or traditional PCR. All subjects received influenza testing with gold-standard PCR; however, this result was not given to the clinical team. Using gold-standard PCR to define influenza status, we compared antiviral treatment rates between the test sites and the control sites in both influenza positive and negative subjects using a chi-squared test.
Results: Of 1987 enrolled subjects, 185 (9.3%) had influenza. Amongst influenza positive subjects, the test sites had significantly higher rates of antiviral treatment (61, 72%) compared to the control sites (23, 21%) (p < 0.001). The test group also had higher rates of antiviral treatment (41, 4.4%) in influenza negative subjects compared to the control group (8, 1.0%) (p < 0.001).
Conclusion: Integrating highly sensitive molecular-based influenza testing into ED practice impacts antiviral treatment, and increases adherence with CDC antiviral treatment guidelines.