Cost-effectiveness analysis of inhaled zanamivir in the treatment of influenza A and B in high-risk patients.
OBJECTIVE
To evaluate the cost effectiveness of zanamivir 10 mg twice daily for 5 days in the treatment of influenza in high-risk patients.


METHODS
Bootstrap cost-effectiveness analysis incorporating within-trial analysis of pooled patient-level cost and effect data.


METHODS
UK unit costs and utilities applied to high-risk patients drawn from 6 multinational clinical trials.


METHODS
A total of 154 zanamivir and 167 placebo high-risk patients were included in the analysis.


METHODS
Cost per day of normal activities; cost per symptom-free day; cost per complication averted; cost per quality-adjusted life-year (QALY).


RESULTS
The mean benefit was estimated to be 2.5 days [95% confidence interval (CI): 0.68 to 4.27] of normal activities gained; 2.0 (95% CI: 0.56 to 3.51) symptom-free days; and a 9% reduction in complications (95% CI: 0 to 18%). Excluding the effect of rare hospitalisation costs, the cost (1999 values) of gaining a day of normal activities was 9.50 Pounds (95% CI: 5 Pounds to 39 Pounds); cost per symptom-free day was 11.56 Pounds (95% CI: 6 Pounds to 43 Pounds); cost per complication averted was 262 Pounds (95% CI: 90 Pounds to 1574 Pounds). Influenza was estimated to reduce utility by 0.883 per day, demonstrating the debilitating effect of the disease. Extrapolating a day of normal activities to a standard utility measure resulted in a cost per QALY of 3900 Pounds excluding inpatient costs (7490 Pounds including inpatient costs). Cost-effectiveness acceptability curves demonstrated 90% certainty that zanamivir would be cost effective at 8000 Pounds per QALY.


CONCLUSIONS
Significant health benefits can be obtained with zanamivir treatment in high-risk patients. The cost per QALY for zanamivir in these patients compares well with that of other commonly used pharmacological interventions.
Griffin
A D
AD
GlaxoWellcome Research and Development, Greenford, UK.
Perry
A S
AS
Fleming
D M
DM
D000280:Administration, Inhalation; D000328:Adult; D000368:Aged; D000998:Antiviral Agents / Q000627:therapeutic use*; D003362:Cost-Benefit Analysis; D005260:Female; D006146:Guanidines; D006801:Humans; D009980:Influenza A virus; D009981:Influenza B virus; D007251:Influenza, Human / Q000188:drug therapy* / Q000191:economics; D008297:Male; D008875:Middle Aged; D011714:Pyrans; D012794:Sialic Acids / Q000008:administration & dosage / Q000627:therapeutic use*; D053243:Zanamivir
D000998:Antiviral Agents; D006146:Guanidines; D011714:Pyrans; D012794:Sialic Acids; D053243:Zanamivir