INFLUENZA VACCINATION PROGRAMS FOR ELDERLY PERSONS - COST-EFFECTIVENESS IN A HEALTH MAINTENANCE ORGANIZATION

Objective: To estimate the cost-effectiveness and net medical care cos ts of programs for annual influenza vaccinations for the elderly in a health maintenance organization (HMO). Design: Population-based, case- control study. Setting: The Northwest Region of Kaiser Permanente, a p repaid group practice HMO in Portland, Oregon. Participants: Kaiser Pe rmanente members 65 years of age and older who had at least 1 month of HMO eligibility during any of nine influenza seasons in the 1980s. Me asurements: The HMO's costs for providing medical care and conducting Vaccination programs were estimated using accounting data. Results: 32 % of high-risk elderly persons and 22% of non-high-risk elderly person s received influenza vaccinations. Aggregate vaccine effectiveness in preventing pneumonia and influenza hospitalizations was 30% (95% CI, 1 7% to 42%) for high-risk and 40% (CI, 1% to 64%) for non-high-risk eld erly persons. The net savings to the HMO per vaccination was $6.11 for high-risk elderly persons and $1.10 for all elderly persons. The HMO incurred a net cost of $4.82 per vaccination for non-high-risk elderly persons. Conclusions: Influenza vaccination rates in this HMO were re latively low for high-risk elderly persons. The medical care costs sav ed by preventing pneumonia and influenza through Vaccination of high-r isk elderly persons provide a compelling rationale to increase complia nce with recommendations for annual influenza vaccination. Indirect be nefits, such as prevention of suffering, incapacity, and lost wages, a re likely to compensate for the small net cost of vaccinating non-high risk elderly persons.