THE IMPACT AND COST OF INFLUENZA IN THE ELDERLY

Background: Traditional methods of measuring the impact and cost of in fluenza virus have focused on epidemic years and morbidity and mortali ty due to pneumonia and influenza. Methods: Annualized age-sex-race ad justed rates of hospitalization for pneumonia and influenza and other diagnoses among elderly Medicare beneficiaries during the epidemic inf luenza season of 1989 to 1990 and the nonepidemic season of 1990 to 19 91 were compared with an interim period in 1990 without influenza viru s circulation. Results: The rates of hospitalization for pneumonia and influenza, acute bronchitis, chronic respiratory disease, and congest ive heart failure were significantly greater during each influenza per iod compared with the interim period. The highest rates were found in the epidemic season of 1989 to 1900. The amount reimbursed by Medicare to hospitals for the treatment of excess hospitalizations during peri ods of influenza activity was more than $1 billion in 1989 to 1990 and almost $750 million in 1990 to 1991. Conclusions: Measures of the imp act and cost of influenza in elderly Americans should include all of t he diagnoses listed above and should recognize that the impact of infl uenza virus is significant even in nonepidemic years. There are great opportunities for cost savings if effective control programs are imple mented.