1039. Impact of Rapid Influenza Testing on the Specificity of Clinical Care In the Emergency Department
Session: Poster Abstract Session: Diagnostic Procedures in Clinical Practice
Saturday, October 22, 2011
Room: Poster Hall B1
Background:  Rapid influenza testing (RIT) has the potential to influence physician decision-making at the onset of care, and to direct downstream patient management. Single-center studies conducted in emergency departments (EDs) suggest that use of RIT may reduce ancillary testing and antibiotic prescribing for patients with respiratory symptoms. Our objective was to examine the impact of RIT on patient management in a national sample of ED visits. 

Methods: We used the National Hospital Ambulatory Medical Care Survey, a nationally representative dataset of visits to EDs in the United States to identify patient visits where influenza was diagnosed by ICD9 code and/or RIT was performed during the winter months of 2007 and 2008. We examined rates of antiviral and antibiotic prescribing and use of ancillary diagnostic testing (chest x-ray, CBC and urinalysis) for three patient groups: (1) influenza diagnosis/RIT performed; (2) influenza diagnosis/RIT not performed; (3) no influenza diagnosis/RIT performed. 

Results: RIT was performed at 3.1 million visits, accounting for 2% of all ED visits during the study period. Among patients in whom an RIT was performed and a diagnosis of influenza was given, antiviral use was markedly higher and the use of antibiotics and ancillary tests was significantly lower compared other patient groups (Table).



Estimated Number of Visits




Ancillary Testing

Antibiotic Use

Antiviral Use

(1) Influenza Diagnosis/RIT performed  





(2) Influenza Diagnosis/RIT not performed





(3) No Influenza Diagnosis/RIT performed





p (trend)






Conclusion: Use of RIT is associated with clinical care specifically directed towards influenza, including increased use of antivirals and decreased use of antibiotics and ancillary testing. This suggests that, despite limitations in RIT sensitivity and specificity, their use influences care. Improvement in the accuracy and availability of RIT along with the development of point-of-care testing for other respiratory pathogens has the potential to improve the quality of care for patients with respiratory illnesses.

Subject Category: J. Clinical practice issues

Anne Blaschke, MD, PhD1, Adam L. Hersh, MD, PhD1, Daniel J. Shapiro, BA2, Carrie L. Byington, MD1 and Andrew Pavia, MD, FIDSA1, (1)Department of Pediatrics, Division of Pediatric Infectious Diseases, University of Utah School of Medicine, Salt Lake City, UT, (2)Pediatrics, University of California, San Francisco, San Francisco, CA


A. Blaschke, Idaho Technology, Inc.: Collaborator, Licensing agreement or royalty and subcontract on NIH grant

A. L. Hersh, None

D. J. Shapiro, None

C. L. Byington, Idaho Technology, Inc.: Collaborator, Licensing agreement or royalty and subcontract on NIH grant

A. Pavia, Idaho Technology, Inc.: Collaborator, subcontract on NIH grant
Pfizer: Consultant, Consulting fee

Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.