BACKGROUND: Emergency departments (EDs) become more overcrowded during peak respiratory virus season. Distinguishing influenza from other viruses is crucial to implement social distancing practices, early treatment, and prompt disposition. OBJECTIVES: We sought to determine factors associated with influenza among a prospective cohort of consecutive ED patients with acute respiratory illness (ARI). METHODS: Between December 2016 and March 2017, trained research assistants screened consecutive ED patients with ARI symptoms. ARI criteria included measured fever at home or in the ED >38°C and a cough, sore throat, or rhinorrhea with a duration of symptoms >12 hours and <1 week. After consent, research assistants collected demographics and clinical history using a standardized data form, and patients had a polymerase chain reaction-based assay that is nearly 100% sensitive for influenza. Univariate analysis was conducted on all predictor variables. Significant variables were entered into a multivariate logistic regression model to find factors that were independently associated with influenza. RESULTS: One hundred nineteen patients consented to enrollment and 31% were found to be positive for influenza. Myalgia, the absence of gastrointestinal symptoms (no diarrhea or vomiting), sore throat, chills, headache, and oxygen saturation ≥97% were significant on univariate analysis and were entered into the multivariate model. Myalgia (adjusted odds ratio [AOR] 3.9), the absence of gastrointestinal symptoms (AOR 4.7), and oxygen saturation ≥97% (AOR 2.8) were significant independent factors of influenza. CONCLUSION: The presence of myalgia, the absence of gastrointestinal symptoms, and oxygen saturation ≥97% are factors that can help distinguish influenza from other acute respiratory illnesses in the ambulatory ED population.
BACKGROUND: Emergency departments (EDs) become more overcrowded during peak respiratory virus season. Distinguishing influenza from other viruses is crucial to implement social distancing practices, early treatment, and prompt disposition. OBJECTIVES: We sought to determine factors associated with influenza among a prospective cohort of consecutive ED patients with acute respiratory illness (ARI). METHODS: Between December 2016 and March 2017, trained research assistants screened consecutive ED patients with ARI symptoms. ARI criteria included measured fever at home or in the ED >38°C and a cough, sore throat, or rhinorrhea with a duration of symptoms >12 hours and <1 week. After consent, research assistants collected demographics and clinical history using a standardized data form, and patients had a polymerase chain reaction-based assay that is nearly 100% sensitive for influenza. Univariate analysis was conducted on all predictor variables. Significant variables were entered into a multivariate logistic regression model to find factors that were independently associated with influenza. RESULTS: One hundred nineteen patients consented to enrollment and 31% were found to be positive for influenza. Myalgia, the absence of gastrointestinal symptoms (no diarrhea or vomiting), sore throat, chills, headache, and oxygen saturation ≥97% were significant on univariate analysis and were entered into the multivariate model. Myalgia (adjusted odds ratio [AOR] 3.9), the absence of gastrointestinal symptoms (AOR 4.7), and oxygen saturation ≥97% (AOR 2.8) were significant independent factors of influenza. CONCLUSION: The presence of myalgia, the absence of gastrointestinal symptoms, and oxygen saturation ≥97% are factors that can help distinguish influenza from other acute respiratory illnesses in the ambulatory ED population.