Management of influenza in adults older than 65 years of age: cost-effectiveness of rapid testing and antiviral therapy.
BACKGROUND
Although antiviral therapy is cost-effective in adults, its cost-effectiveness in older adults has not been studied.


OBJECTIVE
To determine the cost-effectiveness of influenza testing and treatment strategies for older adults.


METHODS
Cost-utility decision model.


METHODS
Clinical trials of antiviral drugs and epidemiologic data.


METHODS
Noninstitutionalized adults older than 65 years of age with influenza-like illness.


METHODS
Lifetime.


CONCLUSIONS
Societal.


METHODS
Rapid diagnostic testing or empirical therapy with antiviral drugs.


METHODS
Cost per quality-adjusted life-year (QALY) saved.


RESULTS
Compared with no intervention, empirically treating an unvaccinated 75-year-old patient with amantadine increased life expectancy by 0.0014 QALY at a cost of 1.57 dollars, a cost-effectiveness ratio of 1129 dollars per QALY saved. Compared with amantadine, rapid diagnostic testing followed by treatment with oseltamivir cost 5025 dollars per QALY saved and empirical treatment with oseltamivir cost 10,296 dollars per QALY saved. Testing and treatment strategies were less cost-effective if the patient was vaccinated, ranging from 2483 dollars per QALY saved with amantadine to 70,300 dollars per QALY saved with oseltamivir.


RESULTS
The decision was sensitive to the probability of influenza, the efficacy of oseltamivir in preventing hospitalizations, and hospitalization and case-fatality rates. The decision was not sensitive to the probability or severity of medication side effects, the quality of life for influenza illness or hospitalization, the efficacy of antiviral therapy in shortening influenza illness, or the rapid diagnostic test characteristics.


CONCLUSIONS
For unvaccinated or high-risk vaccinated patients during the influenza season, empirical oseltamivir treatment is cost-effective. For other patients, rapid diagnostic testing followed by treatment with oseltamivir is cost-effective. Empirical amantadine treatment offers a low-cost alternative if patients cannot afford oseltamivir.
Rothberg
Michael B
MB
Division of General Medicine and Geriatrics, Baystate Medical Center, Springfield, MA 01199, USA. Michael.Rothberg@bhs.org
Bellantonio
Sandra
S
Rose
David N
DN
D000081:Acetamides / Q000191:economics / Q000627:therapeutic use; D000368:Aged; D000547:Amantadine / Q000191:economics / Q000627:therapeutic use; D000998:Antiviral Agents / Q000191:economics* / Q000627:therapeutic use*; D003198:Computer Simulation; D003362:Cost-Benefit Analysis; D003661:Decision Support Techniques; D006146:Guanidines; D006801:Humans; D007251:Influenza, Human / Q000150:complications / Q000188:drug therapy* / Q000191:economics*; D053139:Oseltamivir; D011714:Pyrans; D019057:Quality-Adjusted Life Years; D012299:Rimantadine / Q000191:economics / Q000627:therapeutic use; D012680:Sensitivity and Specificity; D012794:Sialic Acids / Q000191:economics / Q000627:therapeutic use; D053243:Zanamivir
D000081:Acetamides; D000998:Antiviral Agents; D006146:Guanidines; D011714:Pyrans; D012794:Sialic Acids; D012299:Rimantadine; D053139:Oseltamivir; D000547:Amantadine; D053243:Zanamivir