Management of influenza symptoms in healthy adults.
OBJECTIVE
To determine the cost-effectiveness of rapid diagnostic testing and empiric antiviral therapy for healthy adults with symptoms of influenza.


METHODS
Cost-effectiveness analysis using a decision model based on previously published data. Outcome measures included costs and quality-adjusted life expectancy.


METHODS
Physician's office.


METHODS
Hypothetically healthy, working adults < 65 years of age presenting with cough and fever during the influenza season.


METHODS
Rapid testing or clinical diagnosis followed by treatment with amantadine, rimantadine, oseltamivir, or zanamivir compared with no antiviral therapy.


RESULTS
Base-case analysis: not giving antiviral therapy is the most expensive and least effective strategy, costing 471 dollars per patient, mostly owing to time lost from work. Amantadine treatment increases life expectancy by 0.0014 quality-adjusted life years (QALYs) while saving 108 dollars per patient relative to no antiviral therapy. Zanamivir is slightly more effective than amantadine, adding 0.0002 QALYs at an incremental cost of 31 dollars, or 133,000 dollars per QALY saved. All other strategies, including testing strategies, are both less effective and more expensive. SENSITIVITY ANALYSIS: The model is sensitive to the probability of influenza infection, proportion of influenza caused by type B, the relative efficacy of the various drugs, and the value of a workday. At a clinical probability of influenza infection > 20%, antiviral therapy is favored. As the proportion of influenza B increases, zanamivir is favored over amantadine. Testing is rarely indicated. Ignoring the costs of lost workdays, amantadine treatment costs 1,200 dollars/QALY saved.


CONCLUSIONS
Antiviral therapy with either amantadine or zanamivir is cost-effective for healthy, young patients with influenza-like illness during the influenza season, depending on the prevalence of influenza B.
Rothberg
Michael B
MB
Division of General Medicine and Geriatrics, Department of Medicine, Baystate Medical Center, Springfield, MA 01199, USA. Michael.Rothberg@bhs.org
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Shunian
S
Rose
David N
DN
D000328:Adult; D000998:Antiviral Agents / Q000009:adverse effects / Q000191:economics* / Q000627:therapeutic use*; D003362:Cost-Benefit Analysis; D003663:Decision Trees; D003955:Diagnostic Tests, Routine / Q000191:economics*; D006801:Humans; D007251:Influenza, Human / Q000188:drug therapy* / Q000191:economics* / Q000453:epidemiology; D008875:Middle Aged; D009976:Orthomyxoviridae Infections / Q000453:epidemiology; D015995:Prevalence; D012680:Sensitivity and Specificity
D000998:Antiviral Agents