LAUSR

Objective: To compare the economic impact of high-dose trivalent (HD) versus standard-dose trivalent (SD) influenza vaccination on direct medical costs for cardio-respiratory hospitalizations in adults aged 65 years or older enrolled in the United States (US) Veteran’s Health Administration (VHA). Methods: Leveraging a relative vaccine effectiveness study of HD versus SD over five respiratory seasons (2010/11 through 2014/15), we collected cost data for healthcare provided to the same study population both at VHA and through Medicare services. Our economic assessment compared the costs of vaccination and hospital care for patients experiencing acute cardio-vascular or respiratory illness. Results: We analyzed 3.5 million SD and 158,636 HD person-seasons. The average cost of HD and SD vaccination was $23.48 (95% CI: $21.29 $25.85) and $12.21 (95% CI: $11.49 $13.00) per recipient, respectively, while the hospitalization rates for cardio-respiratory disease in HD and SD recipients were 0.114 (95% CI: 0.108–0.121) and 0.132 (95% CI: 0.132–0.133) per person-season, respectively. Attributing the average cost per hospitalization of $11,796 (95% CI: $11,685 $11,907) to the difference in hospitalization rates, we estimated savings attributable to HD to be $202 (95% CI: $115 – $280) per vaccinated recipient. Conclusions: For the five-season period of 2010/11 through 2014/15, HD influenza vaccination was associated with net cost savings due to fewer hospitalizations, and therefore lower direct medical costs, for cardio-respiratory disease as compared to SD influenza vaccination in the senior US VHA population. 2019 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).