title: Clinical diagnosis of influenza in the ED.
abstract: BACKGROUND
  Timely and accurate diagnosis of influenza remains a challenge but is critical for patients who may benefit from antiviral therapy. This study determined the test characteristics of provider diagnosis of influenza, final ED electronic medical record (EMR) diagnosis of influenza, and influenza-like illness (ILI) in patients recommended to receive antiviral treatment according to Centers for Disease Control and Prevention (CDC) guidelines. In addition, we evaluated the compliance with CDC antiviral guidelines.
  
  
  METHODS
  A prospective cohort of adults presenting to a tertiary care ED with an acute respiratory illness who met CDC criteria for recommended antiviral treatment were enrolled and tested for influenza. A clinical diagnosis of influenza was assessed by asking the clinician: "Do you think this patient has influenza?" Influenza-like illness was defined according to current CDC criteria.
  
  
  RESULTS
  In this cohort of 270 subjects, 42 (16%; 95% confidence interval [CI], 11%-20%) had influenza. Clinician diagnosis had a sensitivity of 36% (95% CI, 22%-52%) and specificity of 78% (95% CI, 72%-83%); EMR final ED diagnosis had a sensitivity of 26% (95% CI, 14%-42%) and specificity of 97% (95% CI, 94%-99%); ILI had a sensitivity of 31% (95% CI, 18%-47%) and specificity of 88% (95% CI, 83%-92%). Only 15 influenza-positive patients (36%) received antiviral treatment.
  
  
  CONCLUSIONS
  Clinician diagnosis, final ED EMR diagnosis, and ILI have low sensitivity for diagnosing influenza, and there is overall poor compliance with CDC antiviral treatment recommendations. Improved methods of influenza diagnosis are needed to help guide management in the clinical setting.
authors.affiliation: Department of Emergency Medicine, Johns Hopkins University, Baltimore, MD. Electronic address: adugas1@jhmi.edu.
authors.forename: Andrea F
authors.initials: AF
authors.lastname: Dugas
authors.affiliation: Department of Pathology, Johns Hopkins University, Baltimore, MD.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Valsamakis
authors.affiliation: Department of Emergency Medicine, Johns Hopkins University, Baltimore, MD.
authors.forename: Mihir R
authors.initials: MR
authors.lastname: Atreya
authors.affiliation: Department of Emergency Medicine, Johns Hopkins University, Baltimore, MD.
authors.forename: Komal
authors.initials: K
authors.lastname: Thind
authors.affiliation: Department of Emergency Medicine, Johns Hopkins University, Baltimore, MD.
authors.forename: Peter
authors.initials: P
authors.lastname: Alarcon Manchego
authors.affiliation: Department of Emergency Medicine, Johns Hopkins University, Baltimore, MD.
authors.forename: Annum
authors.initials: A
authors.lastname: Faisal
authors.affiliation: Department of Emergency Medicine, Johns Hopkins University, Baltimore, MD; Department of Medicine, Division of Infectious Disease, Johns Hopkins University, Baltimore, MD.
authors.forename: Charlotte A
authors.initials: CA
authors.lastname: Gaydos
authors.affiliation: Department of Emergency Medicine, Johns Hopkins University, Baltimore, MD; Department of Medicine, Division of Infectious Disease, Johns Hopkins University, Baltimore, MD.
authors.forename: Richard E
authors.initials: RE
authors.lastname: Rothman
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D057286:Electronic Health Records; D004636:Emergency Service, Hospital; D005260:Female; D006786:Hospitals, Urban; D006801:Humans; D007251:Influenza, Human / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity
references.citation: J Infect Dis. 1999 Aug;180(2):254-61
references.pmid: 10395837
references.citation: Clin Infect Dis. 2010 Oct 15;51(8):887-94
references.pmid: 20815736
references.citation: Fam Pract. 1998 Feb;15(1):16-22
references.pmid: 9527293
references.citation: N Engl J Med. 1997 Sep 25;337(13):874-80
references.pmid: 9302301
references.citation: Arch Intern Med. 2000 Nov 27;160(21):3243-7
references.pmid: 11088084
references.citation: JAMA. 2004 Sep 15;292(11):1333-40
references.pmid: 15367555
references.citation: Crit Rev Clin Lab Sci. 2011 Sep-Dec;48(5-6):217-49
references.pmid: 22185616
references.citation: Lancet. 2000 May 27;355(9218):1845-50
references.pmid: 10866439
references.citation: MMWR Recomm Rep. 2011 Jan 21;60(1):1-24
references.pmid: 21248682
references.citation: PLoS One. 2009;4(12):e8453
references.pmid: 20041115
references.citation: J Am Board Fam Pract. 2004 Jan-Feb;17(1):1-5
references.pmid: 15014046
references.citation: Ann Emerg Med. 2005 Nov;46(5):412-9
references.pmid: 16271670
references.citation: West J Emerg Med. 2013 Mar;14(2):191-9
references.pmid: 23599869
references.citation: JAMA. 2003 Jan 8;289(2):179-86
references.pmid: 12517228
references.citation: Clin Infect Dis. 2009 Apr 15;48(8):1003-32
references.pmid: 19281331
references.citation: JAMA. 2005 Feb 23;293(8):987-97
references.pmid: 15728170
references.citation: N Engl J Med. 2009 Dec 17;361(25):e114
references.pmid: 19955517