Study design
Adults at high risk for influenza complications according to the Centers
for Disease Control and Prevention (CDC) definition24reporting to four U.S. EDs (Johns Hopkins Hospital, Baltimore, MD (JHH),
Truman Medical Center, Kansas City, MO (TMC), Maricopa Medical Center,
Phoenix, AZ (MMC), and Olive View-UCLA Medical Center, Sylmar, CA (OMC))
were systematically screened by trained research coordinators, who
assessed consecutive ED patients. All adult patients (age ≥18 years)
were assessed for the presence of fever and/or respiratory symptoms,
including documented fever (defined as >100.4°F) measured
in the ED and any of the following, self-reported symptoms beginning
within the previous 7 days: subjective fever, cough, nasal congestion,
sinus congestion, rhinorrhea, sore throat, or shortness of breath. A
patient who reported 1 or more of the above complaints was further
evaluated to determine whether he or she met at least 1 of the 2011 CDC
high-risk for influenza complication criteria for antiviral
medication.24, 25 Those patients, who met the CDC
criteria for influenza antiviral treatment, spoke English, had not had a
diagnosis of influenza within the last 2 weeks, had not been previously
enrolled, and had the ability for follow-up were offered participation
in the study and signed written consent forms. The Institutional Review
Boards at each site approved the study protocol.