[Efficiency of influenza vaccination in the working population in Spain]

Influenza is a major cause of morbidity and mortality worldwide. Currently, licensed influenza vaccines are safe and effective. Any intervention aimed at reducing the burden of illness is worth analyzing from a clinical and economic perspective.

To assess the costs and benefits of an influenza vaccination program in the Spanish working population.

A theoretical model of costs and benefits in terms of productivity savings was developed to compare 2 strategies (vaccination and non-vaccination) in 2 cohorts of 1,000 workers each. The time horizon was 1 year and the study's perspective was societal.

epidemiological and clinical data on the incidence of influenza and the effectiveness of the vaccine. Data on the use of direct and indirect resources were obtained from an expert panel of 5 experts in preventive medicine, microbiology, occupational health, and health economics. Unit costs (euros 2003) were extracted from local databases. A sensitivity analysis was performed with the data on incidence, effectiveness, and work absenteeism due to influenza.

In the base case scenario, influenza vaccine saved 35 Euros per worker, of which 88% were savings in work loss days avoided. Threshold values in the sensitivity analysis were 6% for the incidence of influenza and 1.5 days for absence from work, above which the vaccine leads to net savings.

Influenza vaccination in the Spanish working population might result in net resource savings to society at large.