The cost-effectiveness of a universal influenza vaccination program for adults aged 50–64 years in Australia
Introduction
Influenza is a common viral infection causing significant morbidity and mortality. It is responsible for 2886 hospitalisations and 196 deaths annually amongst Australians aged 50–64 years [1]. Those with underlying risk factors, such as diabetes, cardiovascular disease, chronic respiratory disease, or weakened immune systems are particularly susceptible to influenza complications and mortality. Influenza vaccination offers an effective means of preventing much of this morbidity and mortality.
The National Health and Medical Research Council (NHMRC) recommends vaccination of all individuals aged ≥65 years, individuals (of any age) at increased risk of influenza-related complications, and contacts of high-risk (HR) patients [2]. However, the Australian government only funds influenza vaccine for those aged ≥65 years and Indigenous people aged ≥50 years under the National Immunisation Program (NIP) [3]. No government funded NIP exists for the non-Indigenous population aged 50–64 years, even those for whom vaccine is recommended. These people can purchase influenza vaccine privately or at reduced cost via the government-subsidised Pharmaceutical Benefits Scheme (PBS) [3].
A growing body of evidence indicates vaccination of healthy adults is often cost-saving [4], [5], [6]. Recently, the cost-effectiveness of universal influenza vaccination in those aged 50–64 years in Europe reported favourable results [7], [8], [9].
In the US, the Advisory Committee on Immunization Practices (ACIP) recommends vaccination for all persons aged 50–64 years as a way of increasing vaccination uptake in persons with HR conditions [10]. The ACIP argues that age-based vaccine strategies are more successful than targeting those at HR, and that those without HR conditions still benefit from vaccination [10].
Over one quarter of Australians aged 50–64 years are considered to be at HR of influenza-complications [3]. This age-group achieves annual vaccination rates of approximately 33% (with less than half those at HR being immunised) [3], significantly lower than the 79% influenza vaccination rate achieved under the NIP for Australians aged ≥65 years [3]. Similar vaccination coverage could potentially be achieved in the 50–64 year age-group if the NIP was extended to this group. Given the difficulties identifying and targeting those at HR, lowering the age threshold offers a pragmatic approach to increasing coverage levels in Australia [7]. However, the potential benefits of extending the NIP are not without costs. This study examines the cost-effectiveness of universal vaccination funding for Australians aged 50–64 years.
Section snippets
Methods
A decision tree model (adapted from Aballea et al. [7]) was used to evaluate the cost-effectiveness of extending universal vaccination funding to Australians aged 50–64 years. The model distinguished between those at HR and those at low-risk (LR) of influenza-related complications (Fig. 1). HR included those with chronic diseases such as diabetes mellitus, circulatory disease, respiratory disease, and those with weakened immune systems [2], [3]. Primary disease was defined as influenza-like
Health outcomes
A vaccination program targeted at 50–64-year-olds would reduce the annual number of ILI cases (medically attended and non-attended) by 3124, a 0.09% reduction in the incidence of ILI, from 1.90 to 1.81%. The new policy would also prevent 1172 hospitalisations, 89 deaths and 2805 work days lost (Table 3).
Costs
From a healthcare payer perspective, a new influenza vaccination policy would cost an additional $15.5 million (or an additional $4.40 per person aged 50–64 years). A total of $0.1 million would
Discussion
The incremental cost per QALY gained was less than $9000 from the healthcare payer perspective. This is well below the implied threshold for cost-effectiveness based on past PBAC funding decisions [40]. In the healthcare payer perspective 99% of all simulations were below a cost-effectiveness acceptability threshold of $50,000/QALY gained.
No previously published Australian study has examined the cost-effectiveness of public funding of influenza vaccine in people aged 50–64 years. The Aballea et
Acknowledgements
This research was commissioned by the Influenza Specialist Group. Information in this report has been drawn from data collected by the General Practice Statistics and Classification Unit, the University of Sydney in collaboration with the Australian Institute of Health and Welfare (AIHW). We thank the AIHW for provision of data. AN is funded by a Public Health Postgraduate Scholarship (402920) from the National Health and Medical Research Council (NHMRC) of Australia, and by a GlaxoSmithKline
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Cited by (29)
Cost-benefit analysis of a national influenza vaccination program in preventing hospitalisation costs in Australian adults aged 50–64 years old
2019, VaccineCitation Excerpt :This study focussed on costs and savings to the government from the vaccine effect in preventing the initial respiratory and AMI hospitalisation as this contributes most of the costs of influenza-related disease. Other direct costs associated with influenza-related disease include GP visits for ILI, ED visits and costs of death [2,18]. However, these costs are considered small relative to hospitalisation costs.
Systematic review of the cost-effectiveness of influenza immunization programs
2017, VaccineCitation Excerpt :The different results were driven mostly by differences in vaccine uptake. In each respective study, Maciosek et al. reported an ICER of $28,044USD per QALY gained [26], Newall et al. reported an ICER of $8338AUD per QALY gained [29], and Turner et al. found an ICER of £10,766 per QALY gained [12]. Buxton-Bridges et al. investigated vaccinating all employees at a car manufacturing plant to not vaccinating employees and found that vaccination did not provide an economic benefit to society with an incremental cost of $65.59USD per employee in the first season and $11.17USD per employee in the second season [18].
Uncertainty and variability in influenza cost‐effectiveness models
2011, Australian and New Zealand Journal of Public HealthInfluenza vaccine for healthy adult workers: An issue for health authorities or employers?
2011, Health PolicyCitation Excerpt :In view of these limits, we concluded that the studies reviewed should be considered mere exercises of forecasts based on assumptions and estimates open to the authors’ discretion, hence colored by either their personal beliefs on this vaccination or manufacturers’ influence in the case of sponsored studies [17,21]. Therefore their optimistic conclusions on the benefits of massive anti-influenza vaccination of 50–64-year-olds should be interpreted very cautiously, as confirmed by a recent international review [29] which included the two studies published in the meantime up to April 2010 [19,30], and reached very similar conclusions to ours. Bearing in mind the intrinsic limits evidenced by the initial review, we then made a deliberately conservative estimate on the Italian setting [25], inspired by the only study that applied CBA instead of CUA and chose a short-term perspective (one influenza season) [23], thus excluding mortality rates from the analysis (Table 1).
A lower than expected adult Victorian community attack rate for pandemic (H1N1) 2009
2010, Australian and New Zealand Journal of Public Health
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