Cost-effectiveness of free influenza vaccination policy for Chinese older adults: a modeling analysis using real-world data.

OBJECTIVE: Vaccination serves as the most efficacious intervention to prevent influenza-related illness. The aim of this study was to compare the lifetime cost-effectiveness of a fully-funded trivalent inactivated influenza vaccine (TIV) strategy for people aged 60 years and over. METHODS: A static decision-tree Markov model was employed to conduct a lifetime economic evaluation from a societal perspective. Model parameters such as probabilities, costs and utility values, were derived from regional health information platform, published literature, and investigation. The number of cases and deaths averted, quality-adjusted life years (QALYs) gained, and the incremental cost-effectiveness ratio (ICER) were predicted. Sensitivity analyses were performed to evaluate the uncertainty of results. RESULTS: Compared with self-paid vaccination, the implementation of the free influenza vaccination program is projected to cumulatively reduce 261,374 non-medically attended influenza cases,370,155 outpatient influenza cases, 13,678 hospitalized influenza cases, and 1987 influenza-associated deaths. It is estimated that this programme will generate cumulative cost savings of $2,184,312 and an additional 14,324 QALYs, rendering it a dominant strategy. At a willingness-to-pay (WTP) threshold of one times of the per capita gross domestic product (GDP) of Ningbo, the probability of the programme being cost-effective is 99.88%. The threshold analysis revealed that the threshold price of TIV is $11.18 under the most conservative WTP threshold. CONCLUSIONS: It has been demonstrated that the free influenza vaccination policy are cost-effective for the elderly individuals. The government and health authorities are supposed to implement and promote a universal free influenza vaccination programme for the elderly, with particular emphasis on the oldest age groups.