Objective: Influenza vaccination rates remain far below national goals in the US. Expanding influenza vaccination in non-traditional settings such as worksites and pharmacies may be a way to enhance vaccination coverage for adults, but scant data exist on the cost effectiveness of this strategy. The aims of this study were to (i) describe the costs of vaccination in non-traditional settings such as pharmacies and mass vaccination clinics; and (ii) evaluate the projected health benefits, costs and cost effectiveness of delivering influenza vaccination to adults of varying ages and risk groups in non-traditional settings compared with scheduled doctor's office visits. All analyses are from the US societal perspective.
Methods: We evaluated the costs of influenza vaccination in non-traditional settings via detailed telephone interviews with representatives of organizations that conduct mass vaccination clinics and pharmacies that use pharmacists to deliver vaccinations. Next, we constructed a decision tree to compare the projected health benefits and costs of influenza vaccination delivered via non-traditional settings or during scheduled doctor's office visits with no vaccination. The target population was stratified by age (18-49, 50-64 and >or=65 years) and risk status (high or low risk for influenza-related complications). Probabilities and costs (direct and opportunity) for uncomplicated influenza illness, outpatient visits, hospitalizations, deaths, vaccination and vaccine adverse events were derived from primary data and from published and unpublished sources.
Results: The mean cost (year 2004 values) of vaccination was lower in mass vaccination (dollars US 17.04) and pharmacy (dollars US 11.57) settings than in scheduled doctor's office visits (dollars US 28.67). Vaccination in non-traditional settings was projected to be cost saving for healthy adults aged >or=50 years, and for high-risk adults of all ages. For healthy adults aged 18-49 years, preventing an episode of influenza would cost dollars US 90 if vaccination were delivered via the pharmacy setting, dollars US 210 via the mass vaccination setting and dollars US 870 via a scheduled doctor's office visit. Results were sensitive to assumptions on the incidence of influenza illness, the costs of vaccination (including recipient time costs) and vaccine effectiveness.
Conclusion: Using non-traditional settings to deliver routine influenza vaccination to adults is likely to be cost saving for healthy adults aged 50-64 years and relatively cost effective for healthy adults aged 18-49 years when preferences for averted morbidity are included.