PURPOSE: To evaluate the cost-effectiveness of delivering inactivated influenza vaccinations to adults in non-traditional settings. Despite the morbidity and mortality associated with influenza illness, vaccination coverage rates remain well below Healthy People 2010 goals for groups that are recommended to receive influenza vaccination. Non-traditional settings may represent an opportunity for boosting influenza immunization coverage rates for recommended adults.

METHODS: A decision tree was developed to predict the costs and health effects of inactivated influenza vaccination in various settings compared with no vaccination. Non-traditional settings included in the analysis were (1) mass vaccination clinics that can be conducted at a variety of locations such as employer sites, retail stores, or pharmacies and (2) pharmacies that use pharmacists to deliver vaccinations. The traditional setting was defined as the physician office with a scheduled appointment for vaccination. The target population was stratified by age (18-49 yrs, 50-64 yrs, and 65+ yrs) 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 based on primary and secondary data. Costs of vaccination in non-traditional settings were collected via telephone surveys with representatives of organizations that conduct mass vaccination clinics and pharmacies. Primary outcomes reported were $/influenza event averted, $/hospitalization averted, and $/death averted. Influenza events included uncomplicated influenza illnesses, influenza-related hospitalizations, and influenza-related deaths. Sensitivity analyses were conducted including a probabilistic sensitivity analysis.

RESULTS: For healthy 18-49 year olds, cost per influenza event averted for vaccination in the pharmacy setting was $140 (95% probability interval: cost saving - $1200), $260 (cost saving-$1800) in the mass vaccination setting, and $1150 ($390-$6200) in the traditional setting. Vaccination was more likely to be cost-saving as age increased. Cost-effectiveness ratios were more favorable for high-risk as compared with healthy adults in the same age group. Results were sensitive to assumptions regarding probability of influenza illness, costs of vaccination (including patient time costs), and vaccine effectiveness.

CONCLUSION: Compared to delivering influenza vaccination through scheduled visits in the traditional physician office setting, cost-effectiveness of influenza vaccination in adults may be more favorable in non-traditional settings. Non-traditional settings may represent a more convenient setting for vaccination at comparable or better cost-effectiveness than the traditional physician office setting.