Theme article
Influenza Vaccination: Health Impact and Cost Effectiveness Among Adults Aged 50 to 64 and 65 and Older

https://doi.org/10.1016/j.amepre.2006.03.008Get rights and content

Background

Influenza causes approximately 36,000 deaths per year in the United States despite the presence of an effective vaccine. This assessment of the value of influenza vaccination to the U.S. population is part of an update to the 2001 ranking of clinical preventive services recommended by the U.S. Preventive Services Task Force. The forthcoming ranking will include the new recommendation of the Advisory Committee on Immunization Practices to extend influenza vaccination to adults aged 50 to 64 years.

Methods

This service is evaluated on the two most important dimensions: burden of disease prevented and cost effectiveness. Study methods, described in a companion article, are designed to ensure consistency across many services.

Results

Over the lifetime of a birth cohort of 4 million, it is estimated that about 275,000 quality-adjusted life years (QALYs) would be saved if influenza vaccination were offered annually to all people after age 50. Eighty percent of the QALYs saved (220,000) would be achieved by offering the vaccine only to persons aged 65 and older. In year 2000 dollars, the cost effectiveness of influenza vaccination is $980 per QALY saved in persons aged 65 and older, and $28,000 per QALY saved in persons aged 50 to 64. When the costs of patient time and travel are excluded, the cost effectiveness ratio of vaccinating 50- to 64-year-olds decreases to $7200 per QALY saved, and vaccinating those aged 65 and older saves $17 per person vaccinated.

Conclusions

Influenza vaccination is a high-impact, cost-effective service for persons aged 65 and older. Vaccinations are also cost effective for persons aged 50 to 64.

Introduction

Influenza epidemics cause, on average, 36,000 deaths per year in the United States. As part of the adult immunization schedule, the Advisory Committee on Immunization Practices (ACIP) recommends annual influenza vaccinations for both persons aged 65 and older (due to increased risk for complications) and for persons aged 50 to 64 years, due to a higher prevalence of certain chronic medical conditions among this group.1, 2

Influenza vaccination coverage increased throughout the 1990s, but significant gaps remain between current vaccination levels and Healthy People 2010 goals. Between January and March 2004, 70.3% of adults aged 65 years and older and 40.6% of those aged 50 to 64 years reported an influenza shot in the last 12 months. Hispanic and non-Hispanic black adults aged 65 and older reported much lower vaccination coverage: 54.3% and 50%, respectively.3 Only one third of high-risk groups aged less than 65 were vaccinated (those with cardiovascular disease or respiratory diseases, among others).4

This assessment of the health impact and cost effectiveness of influenza immunization for the population aged 50 and older and the accompanying articles5, 6, 7, 8 in this issue of the American Journal of Preventive Medicine are part of the update to Partnership for Prevention’s 2001 ranking of 30 clinical preventive services.9, 10 The National Commission on Prevention Priorities (NCPP) guided development of the updated ranking. The NCPP chose to evaluate services based on the same criteria used previously: (1) clinically preventable burden (CPB) as a measure of health impact, and (2) cost effectiveness.9, 10 This article describes the updated estimates of CPB and cost effectiveness for influenza vaccination, reflecting new evidence, more thorough review and analyses, and the revised recommendation of the ACIP to extend vaccinations to persons aged 50 to 64 years. The marginal value of adding the 50- to 64-year-old age group was of particular interest.

Section snippets

Methods

A detailed description of the study methods can be found in the companion article8 and in a technical report available online.11 The methods were designed primarily to ensure consistency in estimating a service’s CPB and cost effectiveness across many services that differ substantially from one another, while managing an enormous volume of evidence. Key aspects of the methods used to evaluate all services and applications of those methods that are specific to the evaluation of influenza

Results

The main results are shown in the first numeric column of Table 2. Offering influenza vaccination to all people in a birth cohort of 4 million starting at age 50 would prevent approximately 2.64 million cases of influenza-like illness, 180,000 hospitalizations, and 40,500 deaths over the lifetime of a birth cohort. Preventing these events yielded a total of 275,000 QALYs saved.

The average annual net cost of this vaccination is $1.5 billion in year 2000 dollars. Using the quality-of-life

Discussion

These simplified models, which were designed to promote consistency in the evaluation of many services, provided transparent estimates of the benefits and cost effectiveness of offering influenza vaccine to a birth cohort of 4 million individuals starting at age 50. Like all models, the accuracy of the estimate is limited by the accuracy of the most influential data points. Some of the most uncertain data points were found to be the most influential, including patient time costs to receive the

Conclusions

These estimates indicate that influenza vaccinations for adults should remain a high-priority service. Neither new evidence nor the change in the recommended age group to include individuals aged 50 to 64 alter substantially the health impact or the cost effectiveness of adult influenza vaccinations.

References (68)

  • K.L. Nichol et al.

    Cost effectiveness of influenza vaccination for healthy persons between ages 65 and 74 years

    Vaccine

    (2002)
  • K.L. Nichol et al.

    Cost benefit of influenza vaccination in healthy, working adultsan economic analysis based on the results of a clinical trial of trivalent live attenuated influenza virus vaccine

    Vaccine

    (2003)
  • C. Heilman et al.

    Influenzastatus and prospects for its prevention, therapy, and control

    Pediatr Clin North Am

    (1990)
  • N.J. Cox et al.

    Influenza

    Infect Dis Clin North Am

    (1998)
  • W.A. Keitel et al.

    Efficacy of repeated annual immunization with inactivated influenza virus vaccines over a five-year period

    Vaccine

    (1997)
  • C.B. Bridges et al.

    Prevention and control of influenza. Recommendations of the Advisory Committee on Immunization Practices (ACIP)

    MMWR Recomm Rep

    (2003)
  • Notice to readersrecommended adult immunization schedule—United States, 2002–2003

    MMWR Morb Mortal Wkly Rep

    (2002)
  • Early release of selected estimates based on data from the January–March 2004 Health Interview Survey

    (2004)
  • Influenza vaccination levels among persons aged ≥65 years and among persons aged 18–64 years with high-risk conditions—United States, 2003

    MMWR Morb Mortal Wkly Rep

    (2005)
  • L.I. Solberg et al.

    Repeated tobacco-use screening and intervention in clinical practicehealth impact and cost effectiveness

    Am J Prev Med

    (2006)
  • M.V. Maciosek et al.

    Technical report of the National Commission on Prevention Priorities: methods update for priority setting among clinical preventive services

    (2005)
  • A.H. Ahmed et al.

    Effectiveness of influenza vaccine in reducing hospital admissions during the 1989–1990 epidemic

    Epidemiol Infect

    (1997)
  • N.H. Arden et al.

    The roles of vaccination and amantadine prophylaxis in controlling an outbreak of influenza A (H3N2) in a nursing home

    Arch Intern Med

    (1988)
  • W.H. Barker et al.

    Influenza vaccination of elderly persons. Reduction in pneumonia and influenza hospitalizations and deaths

    JAMA

    (1980)
  • C.B. Bridges et al.

    Effectiveness and cost-benefit of influenza vaccination of healthy working adultsa randomized controlled trial

    JAMA

    (2000)
  • M.L. Cartter et al.

    Influenza outbreaks in nursing homeshow effective is influenza vaccine in the institutionalized elderly?

    Infect Control Hosp Epidemiol

    (1990)
  • K.M. Edwards et al.

    A randomized controlled trial of cold-adapted and inactivated vaccines for the prevention of influenza A disease

    J Infect Dis

    (1994)
  • D.S. Fedson et al.

    Clinical effectiveness of influenza vaccination in Manitoba

    JAMA

    (1993)
  • D.M. Fleming et al.

    Study of the effectiveness of influenza vaccination in the elderly in the epidemic of 1989–1990 using a general practice database

    Epidemiol Infect

    (1995)
  • D.A. Foster et al.

    Influenza vaccine effectiveness in preventing hospitalization for pneumonia in the elderly

    Am J Epidemiol

    (1992)
  • T.M. Govaert et al.

    The efficacy of influenza vaccination in elderly individuals. A randomized double-blind placebo-controlled trial

    JAMA

    (1994)
  • S. Gravenstein et al.

    Efficacy of an influenza hemagglutinin-diphtheria toxoid conjugate vaccine in elderly nursing home subjects during an influenza outbreak

    J Am Geriatr Soc

    (1994)
  • P.A. Gross et al.

    Association of influenza immunization with reduction in mortality in an elderly population. A prospective study

    Arch Intern Med

    (1988)
  • G. Meiklejohn et al.

    Unusual outbreak of influenza A in a Wyoming nursing home

    J Am Geriatr Soc

    (1987)
  • Cited by (114)

    • Economic evaluation of seasonal influenza vaccination in elderly and health workers: A systematic review and meta-analysis

      2022, eClinicalMedicine
      Citation Excerpt :

      Overall, twelve studies18,19,21,24,26,28,30–33,35,38 (57·1%), four studies20,22,23,29 (19·1%), and five studies25,27,34,36,37 (23·8%) were assessed as low, moderate, and high risk of bias, respectively (Supplement III). Of the 21 included studies, two studies33,34 were conducted in HWs, 18 studies18–31,35–38 were conducted in elderly, and one study32 was conducted in both HWs and elderly. The INMB in year 2019 was calculated.

    View all citing articles on Scopus
    View full text