OBJECTIVES

Influenza vaccination is the most effective approach for prevention of influenza infection. Elderly aged over 60 years were priority population to receive influenza vaccine recommended by the Chinese Technical Guidelines for Seasonal Influenza Vaccination. This study aims to evaluate the cost-effectiveness of quadrivalent influenza vaccine (QIV) versus trivalent influenza vaccine (TIV) in Chinese elderly.

METHODS

A 1-year decision tree model was designed to simulate the economic and clinical outcomes of QIV versus TIV in a hypothetical cohort of Chinses elderly aged over 60 years. Model inputs were mainly retrieved from published literature. Direct (medical and non-medical) and indirect costs, influenza infection rate, mortality rate, quality-adjusted life-years (QALYs) loss, and incremental cost-effectiveness ratio (ICER) were the primary outcomes simulated from the societal perspective of China. One-way and probabilistic sensitivity analyses were performed to examine the uncertainty of model inputs.

RESULTS

Base-case results showed 1-year mortality rate (0.479% versus 0.492%) and influenza infection rate (6.0% versus 6.2%) of QIV strategy were both lower than those of TIV strategy. QIV strategy cost more (27.94USD versus 25.03USD) at lower QALYs loss (0.00567 versus 0.00582). The ICER (19,400 USD/QALY) of QIV versus TIV was lower than 29,580 USD/QALY of the willingness-to-pay threshold (3*GDP per capita in China), therefore QIV was a cost-effective option. One-way sensitivity analysis found TIV strategy would be cost-effective when the influenza infection rate in unvaccinated patients decreased from 0.072 to 0.0499, vaccine effectiveness of TIV reduced from 0.53 to 0.3672, or relative risk of vaccine effectiveness of QIV versus TIV decreased from 1.16 to 1.111. In 10,000 Monte Carlo simulations, QIV and TIV strategy were cost-effective in 70.33% and 29.67% of the time, respectively.

CONCLUSIONS

QIV strategy appears to be cost-effective compared to TIV strategy for elderly population in China.