Pharmacoeconomics of influenza vaccination for healthy working adults: reviewing the available evidence.

A favourable pharmacoeconomic profile has been well established for influenza vaccination in the elderly. For employers relevant benefits seem to exist for vaccinating healthy working adults to avert absenteeism and related production losses. From a pharmacoeconomic point of view it is relevant to consider whether societal benefits of vaccination for healthy working adults is worthwhile given the costs of vaccination for the community. We searched Medline and Embase using the key words influenza (vaccination) in combination with cost, cost-benefit, cost-effectiveness, efficiency, economic evaluation, health-policy and pharmacoeconomics. From this primary search, we selected 11 studies concerned with the group of healthy working adults. We reviewed these studies according to several criteria: benefit-to-cost (B/C) ratio;vaccine effectiveness, influenza incidence, number of days of work absence due to illness; and relative cost of the vaccine. Three studies on vaccinating healthy working adults found costs exceeding the benefits (B/C-ratio <1). The remaining eight pharmacoeconomic studies found a B/C-ratio of almost two or more. Cost savings are strongly related to the inclusion of indirect benefits related to averted production losses. After exclusion of indirect costs and benefits of production gains/losses, only one of the eight studies remains cost saving. Considering the available pharmacoeconomic evidence, vaccination of healthy working adults in Western countries may be an intervention with favourable cost-effectiveness and cost-saving potentials if indirect benefits of averted production losses are included. Excluding indirect benefits and costs of production losses/gains, cost-saving potentials are limited. Recent international guidelines for pharmacoeconomic research advise the inclusion of production gains and losses in the preferred societal perspective. Hence, on the basis of the available evidence, influenza vaccination of healthy working adults may be recommended from pharmacoeconomic point of view. Pharmacoeconomics do, however, present only one argument for consideration aside from ethical issues, budgetary limits and psychosocial aspects.