AN ECONOMIC EVALUATION of
universal varicella Vaccination in australian infants
Streeton
C1, Tilden D2, Davey P2, Wong J2,
Coleman K2, and Burridge J2
1 GlaxoSmithKline,
Melbourne, Australia
2 M-TAG, Sydney,
Australia
Objective:
To evaluate the economic consequences
of introducing routine infant varicella vaccination onto the Australian
childhood immunisation schedule to reduce the incidence, and associated
morbidity and mortality of this condition.
Methodology: A cost-effectiveness analysis (CEA) comparing infant
vaccination with VarilrixÒ (at 18 months of age) to no vaccination was conducted for two
cohorts aged up to 30 years. The decision analysis model employed a Markov
process using data from key trials & other variables from published
literature on the epidemiology of varicella. The CEA and cost-utility
analyses (CUA) presented the outcomes of vaccination as cases of varicella
infection avoided and Quality Adjusted Life Years (QALYs), respectively.
Only direct costs were considered in these analyses. An additional economic
evaluation was undertaken which included indirect costs. Discount rate of
5% per annum was applied to all costs and outcomes. Sensitivity analyses
were also performed.
Results: CEA
& CUA, without indirect costs, found that vaccination was associated
with an incremental cost of AUS$41.10 per child. Incremental cost per
varicella infection avoided was $74 and the incremental cost per QALY
gained was $9,154. When indirect costs were also included, the modelled
evaluation found that the cost of the vaccination program was $258 less
per individual than without vaccination (ie. cost savings).
Conclusions: These results suggest
that universal infant varicella vaccination is a highly cost-effective
intervention, which significantly reduces the burden of this infection and
its associated complications. In addition, the incremental cost per QALY
ratio estimated in this study compares favourably with the ratios of other
health care interventions.