INTRODUCTION: Routine influenza vaccination is fully reimbursed
in most European countries for people aged over 65 years
and those at high risk of complications. Lowering the age threshold
for routine vaccination would reduce hospitalisations and
deaths, as well as productivity losses during influenza outbreaks.
We performed an economic evaluation of lowering the current
age thresholds of 59 in Germany, and 64 in France, Italy, and
Spain to age 50 in these countries. METHODS: A decision analytic
model was developed comparing a new policy providing
universal reimbursement with current policy covering only those
at high risk of complications in the 50-59/64 age group. We
analysed costs and outcomes one over one influenza season from
the perspectives of third-party payers (TPP) and society. The
primary effectiveness measure was quality-adjusted life-years
(QALYs). Model inputs were obtained from the published literature,
complemented by expert opinion. Deterministic and probabilistic
sensitivity analyses (PSA) were conducted. The value of
acquiring additional information was explored. RESULTS: The
estimated ICERs ranged from €13,156 to €28,568 per QALY
gained from the TPP perspective. At a threshold of €50,000 per
QALY gained, the probabilities of the new policy being costeffective
would be 93% for France, 72% for Germany, 89% for
Italy, and 95% for Spain. From the societal perspective, the cost
per QALY decreased to €9,318 in France and €4,195 in Spain,
while cost savings are predicted for Germany and Italy. The
greatest sources of uncertainty were ILI incidence rate, vaccine
uptake, fatality rate and costs of vaccination. CONCLUSIONS:
Routine influenza vaccination for people over 50 is likely to be
cost-effective in France, Germany, Italy and Spain, and costsaving
from the societal perspective in Germany and Italy. The
scope to reduce decision uncertainty is limited, as much of this
stems from the unpredictable fluctuation in annual ILI incidence
rate.