Background: Influenza epidemics are responsible for considerable mortality and morbidity rates, especially among elderly and high risk groups, and vaccination is the main effective strategy for primary prevention. Objectives: The aim of the study was to analyze the economic impact of influenza vaccination with a particular focus on elderly and high risk groups, independently from age. Methods: A search of cost-effectiveness and cost-utility analyses of influenza vaccination in comparison with no intervention was carried out on PubMed from January 1990 to May 2011. Economic analyses were considered eligible only if they addressed elderly and high risk groups. The quality of selected articles was assessed through Drummond’s checklist. Results: Sixteen cost-effectiveness analyses and four cost-benefit analyses were selected, with a quality judged fairly good. Influenza vaccination appeared to be cost-effective and sometimes cost-saving among elderly, also in terms of deaths averted and years of life gained. Among children at risk, vaccination was shown to be cost-saving from the societal perspective and less costly than other preventive measures, with a cost-benefit ratio of 6.4. Among high risk groups vaccination was cost-effective in all studies but one with respect to patients younger than 65: for adult cancer patients it was either costeffective (Incremental Cost-Effectiveness Ratio of US$224.00 per Quality Adjusted Life Years gained) or cost-saving, averting total costs by US$ 2,107 and US$ 6,338 from the health care and societal perspective respectively. Discussion and implications: Influenza vaccination has a very high economic value, as it allows to allocate resources efficiently and to guarantee a better health state also by avoiding severe complications among elderly and high risk groups. Anyway, the standardization of methods of evaluation would permit the comparability and transferability of results of different studies. The saving of indirect costs should be also considered in addressing economic implications in Public Health.
- Economic evaluation