Vaccine 29 (2011) 3525–3530
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Vaccine
journal homepage: www.elsevier.com/locate/vaccine
Estimating the cost-effectiveness of a national program to eliminate disparities in
influenza vaccination rates among elderly minority groups
Constantinos I. Michaelidis
a,*
, Richard K. Zimmerman
a,b
, Mary Patricia Nowalk
a,b
, Kenneth J. Smith
c
a
University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
b
Department of Family Medicine and Clinical Epidemiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
c
Section of Decision Sciences and Clinical Systems Modeling, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
article info
Article history:
Received 14 September 2010
Received in revised form 19 February 2011
Accepted 28 February 2011
Available online 12 March 2011
Keywords:
Influenza
Vaccination
Disparities
Cost-effectiveness
abstract
Influenza is a major cause of preventable morbidity and mortality in the United States, particularly among
the elderly. Yet, there remain large disparities in influenza vaccination rates across elderly Caucasian
(70%), African-American (50%) and Hispanic (55%) populations, with substantial mortality consequences.
In this study, we built a decision-analysis model to estimate the cost-effectiveness of a hypothetical
national vaccination program designed to eliminate these disparities in influenza vaccination rates. Tak-
ing a societal perspective, we developed a Markov model with a one-year cycle length and lifetime
time horizon. In the base case, we conservatively assumed that the cost of promoting the vaccination
program was $10 per targeted elder per year and that by year 10, the vaccination rate of the elderly
African-American and Hispanic populations would equal the vaccination rate of the elderly Caucasian
population (70%). The cost-effectiveness of the vaccination program compared to no vaccination pro-
gram was $48,617 per QALY saved. Probabilistic sensitivity analyses suggested that at willingness-to-pay
thresholds of $50,000 and $100,000 per QALY saved, the likelihood of the vaccination program being cost-
effective was 38% and 92%, respectively. In an analysis using conservative assumptions, we found that
a hypothetical program to ameliorate disparities in influenza vaccination rates has a moderate to high
likelihood of being cost-effective.
© 2011 Elsevier Ltd. All rights reserved.
1. Introduction
Accounting for more than 200,000 hospitalizations and 30,000
deaths annually, influenza is a major cause of preventable morbid-
ity and mortality in the United States [1–3]. Elderly populations
are particularly vulnerable, with estimates suggesting that 90% of
influenza-attributable deaths occur among people older than age
65 [2].
The clinical benefits of seasonal influenza vaccination in elderly
populations are well established [4,5]. Yet, influenza vaccination
rates in the United States remain far below the 90% target set by the
Healthy People 2010 objective and there are large disparities in vac-
cination rates across minority groups. In those older than 65, only
70% of Caucasians, 50% of African-Americans and 55% of Hispan-
ics reported receiving influenza vaccination in 2008 [6]. Due to the
particular vulnerability of elderly populations, these disparities in
influenza vaccination have real mortality consequences. Estimates
*
Corresponding author at: University of Pittsburgh School of Medicine, M240
Scaife Hall, 3550 Terrace Street, Pittsburgh, PA, 15261, United States.
E-mail address: michaelidis.constant@medstudent.pitt.edu (C.I. Michaelidis).
suggest that more than 1800 deaths per year could be prevented by
eliminating disparities in influenza vaccination rates across racial
groups [7].
Although there is an extensive body of literature regarding
the cost-effectiveness of influenza vaccination in a variety of
populations, to our knowledge, no studies have examined the cost-
effectiveness of interventions aimed specifically at eliminating
disparities in influenza vaccination among minority populations.
To this end, we developed a Markov decision analysis model to
estimate the cost-effectiveness of a hypothetical national influenza
vaccination program designed to eliminate known disparities in
influenza vaccination in elderly African-American and Hispanic
populations.
2. Methods
2.1. Perspective and target population
In the base case analysis, we assumed a societal perspective
and included both direct medical and direct non-medical costs
according to the guidelines of Gold et al. [8]. In a secondary anal-
ysis, we assumed a third party payer perspective and included
only direct medical costs. Our hypothetical cohort was the African-
0264-410X/$ – see front matter © 2011 Elsevier Ltd. All rights reserved.
doi:10.1016/j.vaccine.2011.02.098