tetano
Editor, Senior Moderator
Am J Emerg Med. 2012 Jul 13. [Epub ahead of print]
Diagnostic performance of the BinaxNow Influenza A&B rapid antigen test in ED patients.
Self WH, McNaughton CD, Grijalva CG, Zhu Y, Chappell JD, Williams JV, Talbot HK, Shay DK, Griffin MR.
Source
Department of Emergency Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232-4700, USA.
Abstract
OBJECTIVE:
The objective of this study is to evaluate the diagnostic performance of the BinaxNow Influenza A&B rapid antigen test (RAT) in emergency department (ED) patients.
METHODS:
We prospectively enrolled a systematic sample of ED patients older than 6 months with acute respiratory symptoms or nonlocalizing fever during 3 consecutive influenza seasons (2008-2011). Nasal and throat swabs collected by research personnel were tested for influenza by real-time reverse transcription-polymerase chain reaction (RT-PCR). Clinicians independently ordered RATs during clinical care; these specimens were collected by clinical staff and tested for influenza using the BinaxNow RAT. Patients with both a research RT-PCR and clinical RAT were included in the study. Rapid antigen test diagnostic performance was evaluated using RT-PCR as a criterion standard, with preplanned, stratified analysis for subject age, duration of symptoms, influenza subtype, and polymerase chain reaction cycle threshold, which provides a semiquantitative estimate of viral load.
RESULTS:
Of 561 subjects enrolled, 131 (23.4%) had a positive RT-PCR, and 37 (6.6%) had a positive RAT. Overall, RAT performance included sensitivity of 24.4% (95% confidence interval [CI], 17.5%-32.9%), specificity of 98.8% (95% CI, 97.1%-99.6%), positive predictive value of 86.5% (95% CI, 70.4%-94.9%), negative predictive value of 81.1% (95% CI, 77.4%-84.3%). Rapid antigen test sensitivities were low for all categories of subject age, symptom duration, influenza subtype, and cycle threshold.
CONCLUSION:
The BinaxNow RAT demonstrated high specificity and poor sensitivity in ED patients selected by treating clinicians for influenza testing. A negative RAT is a poor predictor for the absence of influenza in the ED and should not be used as a criterion to withhold antiviral medications.
Copyright ? 2012. Published by Elsevier Inc.
PMID:
22795995
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/22795995
Diagnostic performance of the BinaxNow Influenza A&B rapid antigen test in ED patients.
Self WH, McNaughton CD, Grijalva CG, Zhu Y, Chappell JD, Williams JV, Talbot HK, Shay DK, Griffin MR.
Source
Department of Emergency Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232-4700, USA.
Abstract
OBJECTIVE:
The objective of this study is to evaluate the diagnostic performance of the BinaxNow Influenza A&B rapid antigen test (RAT) in emergency department (ED) patients.
METHODS:
We prospectively enrolled a systematic sample of ED patients older than 6 months with acute respiratory symptoms or nonlocalizing fever during 3 consecutive influenza seasons (2008-2011). Nasal and throat swabs collected by research personnel were tested for influenza by real-time reverse transcription-polymerase chain reaction (RT-PCR). Clinicians independently ordered RATs during clinical care; these specimens were collected by clinical staff and tested for influenza using the BinaxNow RAT. Patients with both a research RT-PCR and clinical RAT were included in the study. Rapid antigen test diagnostic performance was evaluated using RT-PCR as a criterion standard, with preplanned, stratified analysis for subject age, duration of symptoms, influenza subtype, and polymerase chain reaction cycle threshold, which provides a semiquantitative estimate of viral load.
RESULTS:
Of 561 subjects enrolled, 131 (23.4%) had a positive RT-PCR, and 37 (6.6%) had a positive RAT. Overall, RAT performance included sensitivity of 24.4% (95% confidence interval [CI], 17.5%-32.9%), specificity of 98.8% (95% CI, 97.1%-99.6%), positive predictive value of 86.5% (95% CI, 70.4%-94.9%), negative predictive value of 81.1% (95% CI, 77.4%-84.3%). Rapid antigen test sensitivities were low for all categories of subject age, symptom duration, influenza subtype, and cycle threshold.
CONCLUSION:
The BinaxNow RAT demonstrated high specificity and poor sensitivity in ED patients selected by treating clinicians for influenza testing. A negative RAT is a poor predictor for the absence of influenza in the ED and should not be used as a criterion to withhold antiviral medications.
Copyright ? 2012. Published by Elsevier Inc.
PMID:
22795995
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/22795995