Pharmacoeconomics of influenza vaccination in the elderly: reviewing the available evidence

A Perspective on Yoga as a Preventive Strategy for Coronavirus Disease 2019

The pandemic outbreak of coronavirus disease 2019 (COVID-19) infection caused by severe acute respiratory syndrome-coronavirus 2 has led to profound public health crisis. In particular, individuals with preexisting conditions of heart disease, diabetes, cerebrovascular diseases and the elderly are most vulnerable to succumb to this infection. The current COVID-19 emergency calls for rapid development of potential prevention and management strategies against this virus-mediated disease. There is a plethora of evidence that supports the add-on benefits of yoga in stress management, as well as prevention and management of chronic noncommunicable diseases. There are some studies on the effect of yoga in communicable diseases as well but very few for acute conditions and almost none for the rapidly spreading infections resulting in pandemics. Based on the available scientific evidences on yoga in improving respiratory and immune functions, we have formulated very simple doable integrated yoga modules in the form of videos to be practiced for prevention of the disease by children, adults, and the elderly.

Model Comparisons of the Effectiveness and Cost-Effectiveness of Vaccination: A Systematic Review of the Literature

OBJECTIVES

To describe all published articles that have conducted comparisons of model-based effectiveness and cost-effectiveness results in the field of vaccination. Specific objectives were to 1) describe the methodologies used and 2) identify the strengths and limitations of the studies.

METHODS

We systematically searched MEDLINE and Embase databases for studies that compared predictions of effectiveness and cost-effectiveness of vaccination of two or more mathematical models. We categorized studies into two groups on the basis of their data source for comparison (previously published results or new simulation results) and performed a qualitative synthesis of study conclusions.

RESULTS

We identified 115 eligible articles (only 5% generated new simulations from the reviewed models) examining the effectiveness and cost-effectiveness of vaccination against 14 pathogens (69% of studies examined human papillomavirus, influenza, and/or pneumococcal vaccines). The goal of most of studies was to summarize evidence for vaccination policy decisions, and cost-effectiveness was the most frequent outcome examined. Only 33%, 25%, and 3% of studies followed a systematic approach to identify eligible studies, assessed the quality of studies, and performed a quantitative synthesis of results, respectively. A greater proportion of model comparisons using published studies followed a systematic approach to identify eligible studies and to assess their quality, whereas more studies using new simulations performed quantitative synthesis of results and identified drivers of model conclusions. Most comparative modeling studies concluded that vaccination was cost-effective.

CONCLUSIONS

Given the variability in methods used to conduct/report comparative modeling studies, guidelines are required to enhance their quality and transparency and to provide better tools for decision making.

Meditation or exercise for preventing acute respiratory infection (MEPARI-2): A randomized controlled trial

Background

Practice of meditation or exercise may enhance health to protect against acute infectious illness.

Objective

To assess preventive effects of meditation and exercise on acute respiratory infection (ARI) illness.

Design

Randomized controlled prevention trial with three parallel groups.

Setting

Madison, Wisconsin, USA.

Participants

Community-recruited adults who did not regularly exercise or meditate.

Methods

1) 8-week behavioral training in mindfulness-based stress reduction (MBSR); 2) matched 8-week training in moderate intensity sustained exercise (EX); or 3) observational waitlist control. Training classes occurred in September and October, with weekly ARI surveillance through May. Incidence, duration, and area-under-curve ARI global severity were measured using daily reports on the WURSS-24 during ARI illness. Viruses were identified multiplex PCR. Absenteeism, health care utilization, and psychosocial health self-report assessments were also employed.

Results

Of 413 participants randomized, 390 completed the trial. In the MBSR group, 74 experienced 112 ARI episodes with 1045 days of ARI illness. Among exercisers, 84 had 120 episodes totaling 1010 illness days. Eighty-two of the controls had 134 episodes with 1210 days of ARI illness. Mean global severity was 315 for MBSR (95% confidence interval 244, 386), 256 (193, 318) for EX, and 336 (268, 403) for controls. A prespecified multivariate zero-inflated regression model suggested reduced incidence for MBSR (p = 0.036) and lower global severity for EX (p = 0.042), compared to control, not quite attaining the p<0.025 prespecified cut-off for null hypothesis rejection. There were 73 ARI-related missed-work days and 22 ARI-related health care visits in the MBSR group, 82 days and 21 visits for exercisers, and 105 days and 24 visits among controls. Viruses were identified in 63 ARI episodes in the MBSR group, compared to 64 for EX and 72 for control. Statistically significant (p<0.05) improvements in general mental health, self-efficacy, mindful attention, sleep quality, perceived stress, and depressive symptoms were observed in the MBSR and/or EX groups, compared to control.

Conclusions

Training in mindfulness meditation or exercise may help protect against ARI illness.

Limitations

This trial was likely underpowered.

Trial registration

Clinicaltrials.gov NCT01654289

Systematic review of the cost-effectiveness of influenza immunization programs

BACKGROUND

Seasonal influenza immunization programs vary widely across jurisdictions. In Canada, some provinces offer universal programs while others target specific population groups. However, whether targeted or universal programs provide more benefit and value-for-money is unclear. The cost-effectiveness of influenza immunization programs was systematically reviewed to inform policy.

METHODS

Citation databases and the grey literature were searched for economic evaluations of influenza immunization programs. Eligible studies were appraised using the Scottish Intercollegiate Guidelines Network (SIGN) checklist with supplemental WHO vaccine-related questions. Data from high quality studies was extracted and the studies reviewed.

RESULTS

A total of 41influenza immunization studies were identified. Of these, 31 were high quality. For pregnant and postpartum women, vaccinating all versus only high risk women study results ranged from dominance (less costly and more effective) to $9773 per QALY gained (societal) and from dominance to $58,000 per QALY gained (healthcare system). Studies of vaccinating all versus only high risk children found vaccination to be dominant to $47,000 per QALY gained (societal), and dominant to $18,000 per QALY gained (healthcare system). Vaccinating high risk adults was highly cost-effective and vaccinating health care workers resulted in $35,000 per QALY gained. Results for healthy working adults were mixed and sensitive to vaccine uptake, efficacy, and productivity loss.

CONCLUSIONS

From the societal perspective, vaccination was cost-effective for children, pregnant and postpartum women, high risk groups, and in some cases, healthy working age adults. Immunization programs using group administration are more cost-effective than programs using individual administration. The perspective, programmatic design, setting, and inclusion of herd immunity affects cost-effectiveness. In regions with targeted programs, re-evaluating "high risk" criteria and consideration of a universal program is warranted.

An approximation of herd effect due to vaccinating children against seasonal influenza - a potential solution to the incorporation of indirect effects into static models

Background

Indirect herd effect from vaccination of children offers potential for improving the effectiveness of influenza prevention in the remaining unvaccinated population. Static models used in cost-effectiveness analyses cannot dynamically capture herd effects. The objective of this study was to develop a methodology to allow herd effect associated with vaccinating children against seasonal influenza to be incorporated into static models evaluating the cost-effectiveness of influenza vaccination.

Methods

Two previously published linear equations for approximation of herd effects in general were compared with the results of a structured literature review undertaken using PubMed searches to identify data on herd effects specific to influenza vaccination. A linear function was fitted to point estimates from the literature using the sum of squared residuals.

Results

The literature review identified 21 publications on 20 studies for inclusion. Six studies provided data on a mathematical relationship between effective vaccine coverage in subgroups and reduction of influenza infection in a larger unvaccinated population. These supported a linear relationship when effective vaccine coverage in a subgroup population was between 20% and 80%. Three studies evaluating herd effect at a community level, specifically induced by vaccinating children, provided point estimates for fitting linear equations. The fitted linear equation for herd protection in the target population for vaccination (children) was slightly less conservative than a previously published equation for herd effects in general. The fitted linear equation for herd protection in the non-target population was considerably less conservative than the previously published equation.

Conclusions

This method of approximating herd effect requires simple adjustments to the annual baseline risk of influenza in static models: (1) for the age group targeted by the childhood vaccination strategy (i.e. children); and (2) for other age groups not targeted (e.g. adults and/or elderly). Two approximations provide a linear relationship between effective coverage and reduction in the risk of infection. The first is a conservative approximation, recommended as a base-case for cost-effectiveness evaluations. The second, fitted to data extracted from a structured literature review, provides a less conservative estimate of herd effect, recommended for sensitivity analyses.

Further evidence for favorable cost-effectiveness of elderly influenza vaccination

Vaccination represents the single most cost-effective strategy to avert influenza-related morbidity, mortality and economic consequences. This review presents an analysis of the pharmacoeconomic aspects of influenza vaccination of the elderly. The methodology of the analysis focuses on the main drivers of the pharmacoeconomic profile of elderly influenza vaccination, in particular the vaccine effectiveness in terms of prevention of hospitalization and mortality, the background incidence of hospitalization and death in unvaccinated individuals and the relative costing of the vaccine compared with the costs of a hospital in-patient day. The variation in outcomes between different studies could partly be explained by differences in the main drivers defined above. This review demonstrates that the pharmacoeconomic profile of elderly influenza vaccination is highly favorable. From the vast majority of studies it appears that financial benefits of elderly influenza vaccination surpass the costs and that, when this is not the case, cost-effectiveness in terms of net costs per life-year gained is acceptable.

Economic value of influenza vaccination

Influenza epidemics are responsible for high mortality and morbidity rates in particular among elderly and high risk groups. This review is aimed at assessing the economic value of vaccination in these groups. A search of full economic evaluations of influenza vaccination in comparison with no interventions was performed on PubMed from January 1990 to May 2011. Only economic evaluations dealing with elderly and high risk groups were considered. The quality of selected articles was assessed through Drummond's checklist. Sixteen cost-effectiveness analyses and four cost-benefit analyses were included: overall, the quality of studies was fairly good. The vaccination was demonstrated to be cost-effective or cost-saving in almost all studies, independently by the perspective and the type of analysis. Influenza vaccination is a worthwhile intervention from the pharmacoeconomic view-point, anyway a standardization of methods should be desirable in order to guarantee the comparability and transferability of results.

Cost-effective approaches to influenza prevention and treatment

Influenza, the seventh leading cause of death in the USA, accounts for 35,000 deaths and over 200,000 hospitalizations annually in that country alone. Recent advances in influenza vaccines, diagnosis and treatment have created numerous options for practicing clinicians, as well as economic opportunities for the makers of vaccines, rapid diagnostic tests and antiviral drugs. Since influenza-like illness affects up to half of the population each year, selective use of expensive tests and treatments is essential to the practice of cost-effective medicine. Over the past 5 years, dozens of economic evaluations of influenza vaccination, rapid testing and antiviral therapy have been published, many of which are free of commercial bias. The existing literature, drawing practical lessons for clinical practice is reviewed, and new developments on the horizon are explored including vaccines, surveillance methods, antiviral agents and pandemic preparedness.

Economic appraisal of Ontario's Universal Influenza Immunization Program: a cost-utility analysis

BACKGROUND

In July 2000, the province of Ontario, Canada, initiated a universal influenza immunization program (UIIP) to provide free seasonal influenza vaccines for the entire population. This is the first large-scale program of its kind worldwide. The objective of this study was to conduct an economic appraisal of Ontario's UIIP compared to a targeted influenza immunization program (TIIP).

METHODS AND FINDINGS

A cost-utility analysis using Ontario health administrative data was performed. The study was informed by a companion ecological study comparing physician visits, emergency department visits, hospitalizations, and deaths between 1997 and 2004 in Ontario and nine other Canadian provinces offering targeted immunization programs. The relative change estimates from pre-2000 to post-2000 as observed in other provinces were applied to pre-UIIP Ontario event rates to calculate the expected number of events had Ontario continued to offer targeted immunization. Main outcome measures were quality-adjusted life years (QALYs), costs in 2006 Canadian dollars, and incremental cost-utility ratios (incremental cost per QALY gained). Program and other costs were drawn from Ontario sources. Utility weights were obtained from the literature. The incremental cost of the program per QALY gained was calculated from the health care payer perspective. Ontario's UIIP costs approximately twice as much as a targeted program but reduces influenza cases by 61% and mortality by 28%, saving an estimated 1,134 QALYs per season overall. Reducing influenza cases decreases health care services cost by 52%. Most cost savings can be attributed to hospitalizations avoided. The incremental cost-effectiveness ratio is Can$10,797/QALY gained. Results are most sensitive to immunization cost and number of deaths averted.

CONCLUSIONS

Universal immunization against seasonal influenza was estimated to be an economically attractive intervention.

Is a Mass Immunization Program for Pandemic (H1N1) 2009 Good Value for Money? Early Evidence from the Canadian Experience

This work contributes informed estimates to the current debate about the pandemic (H1N1) 2009 mass immunization program's economic merits. We performed a cost-utility analysis of the (H1N1) 2009 mass immunization program in Ontario, Canada's most populous province. The analysis is based on a simulation model of a pandemic (H1N1) 2009 outbreak, surveillance data, and administrative data. We consider no immunization versus mass immunization reaching 30% of the population. Immunization program costs are expected to be $118 million in Ontario. Our analysis indicates this program will reduce influenza cases by 50%, preventing 35 deaths, and cutting treatment costs in half. A pandemic (H1N1) 2009 immunization program is likely to be highly cost-effective.

Effect of influenza vaccine status on winter mortality in Spanish community-dwelling elderly people during 2002–2005 influenza periods

This study assessed the relationship between the reception of conventional inactivated influenza vaccine and winter mortality in a prospective cohort that included 11,240 Spanish community-dwelling elderly individuals followed from January 2002 to April 2005. Annual influenza vaccine status was a time-varying condition and primary outcome was all-cause death during study period. Multivariable Cox proportional-hazard models adjusted by age, sex and co-morbidity were used to evaluate vaccine effectiveness. Influenza vaccination was associated with a significant reduction of 23% in winter mortality risk during overall influenza periods. The attributable mortality risk in non-vaccinated people was 24 deaths per 100,000 persons-week within influenza periods, the prevented fraction for the population was 14%, and one death was prevented for every 239 annual vaccinations (ranging from 144 in Winter 2005 to 1748 in Winter 2002).

Universal influenza vaccination: the time to act is now

Annual influenza epidemics create a significant public health burden each year in the United States. That influenza continues to pose a public health threat despite being largely preventable through vaccination is indicative of continuing weaknesses in the U.S.'s public health system. Moreover, the burden of annual influenza epidemics and the fragility and instability of the capacity to respond to them underscore the U.S.'s ongoing vulnerability to pandemic influenza and highlights gaps in bioterrorism preparedness and response efforts. This article examines the burden of annual influenza epidemics in the U.S., efforts to combat that burden with vaccination, shortcomings of influenza vaccination efforts, and how those shortcomings exemplify weaknesses in pandemic influenza and bioterrorism preparedness efforts. We make the case for establishing an annual universal influenza vaccination program to assure access to influenza vaccination to anyone who can safely receive vaccination and desires it. Such a program could greatly reduce the annual burden of influenza while advancing and maintaining U.S. pandemic influenza and bioterrorism preparedness and response efforts.

Panning for gold: an evidence-based tool for assessment of performance indicators in primary health care

It is important that debate occurs between theorists, policy makers, clinicians and service end-users to develop agreement over suitable and appropriate indicators for primary health care. A formal accounting of the relative strengths and weaknesses of any proposed indicator will enable sector commentators from a variety of viewpoints to discuss the relative merits of individual indicators, to understand the political and pragmatic reasons for their inclusion in any set of indicators and to trace the likely organisational impact of any given indicator. This paper details the development of an indicator appraisal tool that combines the assessment of scientific evidence with contextual considerations from the perspective of both the policy environment and the primary health care sector. The use of the tool is discussed in the context of the proposed national implementation of a set of performance indicators in New Zealand.

Scenarios on costs and savings of influenza treatment and prevention for Dutch healthy working adults

OBJECTIVE

To assess the economic implications of strategies for influenza control among healthy working adults in The Netherlands.

METHODS

The economic evaluation was based on a pharmaco-economic model from the societal perspective. This model involves the direct and indirect costs of vaccination or treatment and the direct and indirect savings (averted costs) due to the control strategy. Control strategies comprised treatment with oseltamivir and prevention with the influenza vaccine. Clinical and economic parameter estimates were derived from published literature, databases and expert opinions. Several scenarios for age-groups and employment contracts (full-time versus not) were elaborated in combination with Monte Carlo simulation for probabilistic sensitivity analysis.

RESULTS

Consistently, net cost savings are estimated over the range of age groups and scenarios considered. Net savings are smallest for half-time workers. Incremental analysis indicates that on average prevention renders higher cost savings than treatment.

CONCLUSION

We found a consistent picture of net cost savings for prevention through vaccination and treatment with oseltamivir of influenza in healthy working adults in The Netherlands.

Influenza vaccine in the elderly and chronic obstructive pulmonary disease

Influenza viruses are RNA viruses that are a major determinant of morbidity and mortality caused by respiratory disease. Influenza is highly contagious and has caused epidemics and pandemics for centuries. Most influenza infections are self- limited, but lower respiratory tract and cardiac complications can result in increases in hospitalizations and deaths. The recommended composition of influenza vaccine is updated annually in order to provide a vaccine that is antigenically well matched with the new influenza virus strains that are expected to cause epidemics. Influenza vaccination significantly reduces mortality; however, approximately one third of elderly Americans are not immunized annually. The nation's goal is to increase the influenza vaccination rate among the elderly to 90%. Vaccination is the most effective measure for reducing the impact of influenza and is a cost-effective preventive health intervention for the elderly and individuals with chronic obstructive pulmonary disease.

Influenza vaccination and antiviral therapy: is there a role for concurrent administration in the institutionalised elderly?

Influenza vaccination is estimated to be 50-68% efficacious in preventing pneumonia, hospitalisation or death in nursing home residents. Large culture-proven outbreaks may occur despite high resident vaccination rates. There is, therefore, a significant role for concurrent administration of influenza vaccination and antiviral therapy. The use of antiviral treatment and chemoprophylaxis requires community reporting of viral isolates, and contingency plans for rapid case identification and application of antiviral therapy. Clinicians must react quickly to control a highly infectious seasonal pathogen that may strike as an explosive outbreak. This situation is unique in geriatric practice. Current antiviral treatment should be administered within 48 hours of symptom onset, and is more efficacious if administered within 12 hours. In the case of an explosive institutional outbreak, a 1-day delay in prophylaxis may allow infection of many residents with a potentially fatal illness. Influenza must be differentiated from other respiratory viruses or syndromes. Grouped rapid diagnostic tests can aid laboratory confirmation. Antiviral agents include the M(2) inhibitors, amantadine and rimantadine, active against influenza A, and the neuraminidase inhibitors, zanamivir and oseltamivir, active against influenza A and B. In our experience, influenza B illness is as severe as influenza A. All agents have similar efficacy as treatment and prophylaxis against sensitive strains. When M(2) inhibitors are used simultaneously within an enclosed space (i.e. household or nursing home) as both treatment and prophylaxis, resistant strains may emerge that limit prophylactic efficacy. When M(2) inhibitors are administered to suspected cases (residents or staff) in institutions, precautions against secretion are especially important to diminish the risk of transmission of resistant virus. Rimantadine has been shown to have significantly fewer CNS adverse events compared with amantadine. Amantadine and oseltamivir require dosage adjustment in those with renal impairment. Oseltamivir, rimantadine and amantadine are administered by mouth, while zanamivir is administered by oral inhalation in a lactose powder. The labelling advises caution in the use of zanamivir in those with underlying airway disease. Pooled analysis of studies in patients given zanamivir indicate that individuals over the age of 50 years (at high risk for complications) and those severely symptomatic at presentation, tend to benefit most from early treatment. Neuraminidase inhibitors also diminish the need for antibacterials to treat secondary complications. An institutional programme to control influenza should include vaccination, and contingency plans for clinical surveillance, specimen processing and the rapid application of antiviral treatment and prophylaxis.

Pharmacoeconomics of influenza vaccination for healthy working adults: reviewing the available evidence

A favourable pharmacoeconomic profile has been well established for influenza vaccination in the elderly. For employers relevant benefits seem to exist for vaccinating healthy working adults to avert absenteeism and related production losses. From a pharmacoeconomic point of view it is relevant to consider whether societal benefits of vaccination for healthy working adults is worthwhile given the costs of vaccination for the community. We searched Medline and Embase using the key words influenza (vaccination) in combination with cost, cost-benefit, cost-effectiveness, efficiency, economic evaluation, health-policy and pharmacoeconomics. From this primary search, we selected 11 studies concerned with the group of healthy working adults. We reviewed these studies according to several criteria: benefit-to-cost (B/C) ratio;vaccine effectiveness, influenza incidence, number of days of work absence due to illness; and relative cost of the vaccine. Three studies on vaccinating healthy working adults found costs exceeding the benefits (B/C-ratio <1). The remaining eight pharmacoeconomic studies found a B/C-ratio of almost two or more. Cost savings are strongly related to the inclusion of indirect benefits related to averted production losses. After exclusion of indirect costs and benefits of production gains/losses, only one of the eight studies remains cost saving. Considering the available pharmacoeconomic evidence, vaccination of healthy working adults in Western countries may be an intervention with favourable cost-effectiveness and cost-saving potentials if indirect benefits of averted production losses are included. Excluding indirect benefits and costs of production losses/gains, cost-saving potentials are limited. Recent international guidelines for pharmacoeconomic research advise the inclusion of production gains and losses in the preferred societal perspective. Hence, on the basis of the available evidence, influenza vaccination of healthy working adults may be recommended from pharmacoeconomic point of view. Pharmacoeconomics do, however, present only one argument for consideration aside from ethical issues, budgetary limits and psychosocial aspects.

Influenza and pneumococcal vaccination in Scottish nursing homes: coverage, policies and reasons for receipt and non-receipt of vaccine

A national survey was carried out to determine the coverage of influenza and pneumococcal vaccines, policies, reasons for receipt, non-receipt of vaccine and strategies to improve vaccine coverage in Scottish nursing homes. Of the 550 nursing homes, 72% (394) participated in the study. Overall coverage was 85% for influenza vaccine in 2001-2002 season and 11% for pneumococcal vaccine in the last 5-year period. Only 6% (23/394) of homes were reported to have a systematic immunization record. The most frequently stated reasons for improved coverage of both vaccines were clear immunization policies (76%), awareness and education for staff and residents (68%), and consent on behalf of the incompetent residents (66%). The presence of vaccination policies was higher for influenza vaccine than pneumococcal vaccine expressed as verbal agreement (27% versus 3%), written policies with set target (24% versus 5%) and written policies without set target (17% versus 2%). Advice from the members of the community health care team was the principal reason for the receipt of both vaccines. The predominant reasons for non-receipt of vaccine were refusal by residents and family members (both vaccines) and lack of advice from general practitioners (pneumococcal vaccine). The substantial disparity in coverage of influenza and pneumococcal vaccine reflects the lack of national recommendations and policies for reimbursements for pneumococcal vaccination. These data suggest that greater efforts are needed to improve prevention behaviors of health care professionals and the public, organized vaccine delivery strategies and systematic vaccination documents to increase influenza and pneumococcal vaccination rates in nursing homes and other long-term care facilities.