Cost effectiveness of zanamivir for the treatment of influenza in a high risk population in Australia.
OBJECTIVE
To use data from a clinical trial of zanamivir, a new antiviral drug, to estimate the costs and effectiveness of alternative treatment strategies for a high-risk population in Australia visiting a physician for treatment of influenza or influenza-like illness within 36 hours of symptom onset.


METHODS
This was a modelling study using data from a randomised, double-blind, placebo-controlled trial with centres in Australia, New Zealand and South Africa. Cost data were taken from standard Australian sources.


METHODS
Efficacy data from the clinical trial were used to populate a computer model designed to estimate the costs and health outcomes associated with alternative treatments for influenza and influenza-like illness. Only patients who consulted the physician within 36 hours of symptom onset were included in this trial. Cost data were used to translate the clinical data into treatment cost estimates.


RESULTS
Treatment with zanamivir for this high risk population results in an incremental cost of $A14.20 per day of symptoms avoided in the base case. The cost per quality-adjusted life-year (QALY) gained is $A11,715. The results are sensitive to several parameter values, including the influenza-positive rate and the impact of zanamivir on days to alleviate symptoms and hospitalisation.


CONCLUSIONS
Influenza is costly for the high risk population who seek physician treatment. Treatment with zanamivir for this population is cost effective based on an $A78,000 per QALY benchmark. Zanamivir could be cost saving if it reduces the hospitalisation rate.
Mauskopf
J A
JA
Research Triangle Institute, Research Triangle Park, North Carolina, USA. jom@rti.org
Cates
S C
SC
Griffin
A D
AD
Neighbors
D M
DM
Lamb
S C
SC
Rutherford
C
C
D000998:Antiviral Agents / Q000627:therapeutic use*; D003362:Cost-Benefit Analysis; D004311:Double-Blind Method; D006146:Guanidines; D017048:Health Care Costs; D006801:Humans; D007251:Influenza, Human / Q000188:drug therapy*; D011714:Pyrans; D012794:Sialic Acids / Q000627:therapeutic use*; D053243:Zanamivir
D000998:Antiviral Agents; D006146:Guanidines; D011714:Pyrans; D012794:Sialic Acids; D053243:Zanamivir