Written by John Korducki
Patients at two separate urgent care locations—one with rapid influenza diagnostic testing (RIDT) and one without—were compared on several parameters. Importantly, antibiotic prescribing was significantly lower, and antiviral prescribing was significantly higher in the group with RIDT testing.
Why does this matter?
Antibiotic resistant infections are on the rise both in the U.S. and globally and can lead to deaths in susceptible or even healthy patients. The leading cause of antibiotic resistance is unnecessary antibiotic prescribing, with the CDC estimating 30% of all antibiotic prescriptions as unnecessary (1). Urgent care centers and ERs account for a significant portion of these prescriptions.
Positive for flu? No antibiotics for you!*
This matched pair analysis showed that in a population where RIDT was available (Sofia Influenza A + B Fluorescent Immunoassay, Quidel Corporation, San Diego, CA), there was a significant decrease in antibiotic prescribing compared to the non-RIDT group, OR 0.52 (0.43-0.63), and this rate decreased further among patients in the RIDT group with a positive flu test, OR 0.15 (0.08-0.27). Additionally, prescriptions for antivirals, such as oseltamivir, were much more likely to be prescribed for the RIDT group, OR 3.07 (2.25-4.26), and this ratio jumped even higher in those in the RIDT group with a positive flu test, OR 10.23 (5.78-19.72).
Historically, flu testing in urgent care centers and the ED has been complicated by low sensitivity rapid screens (as were used in this study) or long wait times for PCR testing to return—often coming back after discharge of the patient, who may have already been given a “just in case” prescription for antibiotics. Despite the lower diagnostic accuracy of the tests used in this study, there were still potential gains for antimicrobial stewardship. Unlike what was used in this study, newer generation rapid (20 minute) PCR flu and COVID tests have demonstrated sensitivities and specificities in the high 90s (2). These gold standard point-of-care PCR tests can play an important role in antibiotic stewardship and limiting duration and spread of influenza during peak flu season going forward.
Editor’s note: This study was funded by Quidel, and several authors are employed by Quidel, makers of the rapid flu antigen tests used in this study. The diagnostic accuracy of these antigen tests is not nearly as good as what was purported in the article (i.e. not high 90s). In addition, rapid antigen tests for flu are not recommended by the IDSA. At VUMC, our retail health, walk-in clinic, and ED locations all use gold-standard rapid PCR tests for influenza A, influenza B, and SARS-CoV-2. ~Clay Smith
*I’m making the assumption here of a significant overlap in Seinfeld fandom and JournalFeed readership and hoping some of you read the headline in its intended format—in the voice of the Soup Nazi.
The Influence of Rapid Influenza Diagnostic Testing on Clinician Decision-making for Patients with Acute Respiratory Infection in Urgent Care. Clin Infect Dis. 2023 Feb 1;ciad038. doi: 10.1093/cid/ciad038. Online ahead of print.
- Fleming-Dutra KE, Hersh AL, Shapiro DJ, et al. Prevalence of Inappropriate Antibiotic Prescriptions Among US Ambulatory Care Visits, 2010-2011. JAMA. 2016;315(17):1864-1873. doi:10.1001/jama.2016.4151
- Hansen G, Marino J, Wang ZX, Beavis KG, Rodrigo J, Labog K, Westblade LF, Jin R, Love N, Ding K, Garg S, Huang A, Sickler J, Tran NK. Clinical Performance of the Point-of-Care cobas Liat for Detection of SARS-CoV-2 in 20 Minutes: a Multicenter Study. J Clin Microbiol. 2021 Jan 21;59(2):e02811-20. doi: 10.1128/JCM.02811-20. PMID: 33239382; PMCID: PMC8111162.