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Journal of Occupational & Environmental Medicine:
doi: 10.1097/JOM.0b013e3182677d34
Original Articles

The Comparative Value of Various Employer-Sponsored Influenza Vaccination Clinics

Zimmerman, Richard K. MD, MPH; Wiringa, Ann E. MPH; Nowalk, Mary Patricia PhD; Lin, Chyongchiou J. PhD; Rousculp, Matthew D. PhD, MPH; Mitgang, Elizabeth A.; Lee, Bruce Y. MD, MBA

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Author Information

From the Department of Family Medicine (Drs Zimmerman, Nowalk, and Lin), University of Pittsburgh, Pittsburgh, PA; Public Health Computational and Operations Research (PHICOR) (Ms Wiringa, Ms Mitgang, and Dr Lee), University of Pittsburgh School of Medicine and Graduate School of Public Health, Pittsburgh, PA; and MedImmune, LLC (Dr Rousculp), Gaithersburg, MD.

Address correspondence to: Mary Patricia Nowalk, PhD, RD, 3518 Fifth Ave, Pittsburgh, PA 15213 (tnowalk@pitt.edu).

This study was sponsored by MedImmune, LLC.

Conflicts of Interest: University of Pittsburgh Department of Family Medicine (RKZ, MPN, and CJL): MedImmune, LLC (RKZ, MPN, CJL); Sanofi (RKZ, CJL), Investigator Initiated Research grant; and Merck (RKZ, MPN, CJL) Investigator Initiated Research grant. University of Pittsburgh Public Health Computational and Operations Research (AEW, EAM, and BYL): MedImmune, LLC. Dr Rousculp was a MedImmune employee at the time of this study.

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Abstract

Objective: Many US firms offer influenza vaccination clinics to prevent lost productivity due to influenza. Strategies to promote and offer vaccination differ, and the economic value of the strategies is unknown.

Methods: Decision analytic modeling and Monte Carlo probabilistic sensitivity analyses estimated the one-season cost-consequences of three types of influenza clinics (trivalent inactivated influenza vaccine only, vaccine choice [trivalent inactivated influenza or intranasal {live attenuated influenza} vaccine], or vaccine choice plus incentive) in firms of 50 and 250 employees, from the employer's perspective.

Results: On-site influenza vaccination was generally cost-saving over no vaccination. For the scenario of vaccine effectiveness of 70% and intermediate transmissibility, the incremental costs per employee for a firm of 50 employees were −$6.41 (ie, cost savings) for inactivated vaccine only versus no vaccination, −$1.48 for vaccine choice versus inactivated vaccine, and $1.84 for vaccine choice plus incentive versus vaccine choice. Clinics offering a choice of vaccines were slightly less costly under many scenarios. Generally, incremental costs were lower (1) in larger firms; (2) when influenza was assumed to be more contagious; and (3) when vaccine effectiveness was assumed to be higher.

Conclusion: Employer-sponsored influenza vaccination clinics are generally cost-saving.

Since 2010, seasonal influenza vaccine has been recommended for all individuals older than 6 months in the United States, including more than 137 million working adults.1,2 In addition to thousands of excess doctor's office visits, hospitalizations, and deaths due to influenza each year, the economic burden of influenza extends to business and industry, where the productivity loss attributable to absenteeism and presenteeism (working while sick) is substantial. Influenza has been estimated to cause more than 70 million lost working days and $6.2 billion in lost productivity in the United States each year.3,4 Hence, businesses are increasingly offering wellness programs that include preventive services such as on-site influenza vaccination clinics. A 2004 survey5 determined that 70% of US corporations surveyed offer influenza vaccines in the workplace. During the 2010–2011 vaccination season, 25.7% of influenza vaccinations among adults ages 18 to 49 years and 21.1% of vaccinations among adults ages 50 to 64 years were administered in the workplace, making it the second most common vaccination location outside a doctor's office.6

Annual workplace influenza vaccination, with its effect of reducing absenteeism and presenteeism,7 offers documented benefit to employers.810 Using decision analytic modeling, Lee et al11 determined worksite influenza vaccination programs to be relatively inexpensive from the employer perspective. In many scenarios, vaccination programs were cost-saving across a range of occupational groups when the average number of secondary cases generated per primary case was 1.2 or greater. Hence, maximizing workplace vaccination rates is an efficient use of resources.

Although some businesses, especially larger companies, successfully vaccinate a majority of their employees, workplace influenza vaccination rates have generally languished. In two reports,12,13 only 15% to 18% of companies surveyed reported that more than 50% of their employees were vaccinated at on-site influenza vaccination clinics. A third study14 reported influenza vaccination rates among 90 businesses ranging from 9% to 62% with a mean of 37%. In 2008, a study was conducted to improve workplace influenza vaccination rates by offering eligible employees a choice of either trivalent inactivated influenza vaccine (TIV) or live attenuated influenza vaccine (LAIV). Fifty-three businesses with more than 50 employees were randomly assigned to 1 of the 3 influenza vaccination clinics as follows: (1) control, which offered TIV; (2) choice, which advertised and offered either TIV or LAIV to eligible employees; and (3) choice plus, which advertised and offered TIV or LAIV to eligible employees and a small incentive to vaccinees, regardless of which vaccine was given. Primary results indicated that, compared with companies assigned to the control clinic, companies that advertised and offered a choice of vaccines nonsignificantly increased vaccination rates, whereas those that advertised and offered a choice of vaccines plus a nominal incentive significantly increased vaccination rates over the previous year.14 The present study used decision analytic modeling to estimate from the employer perspective the cost-consequences of three workplace influenza vaccination strategies based on data from that earlier study.14

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METHODS

Model Overview and Data Inputs

Using TreeAge Pro 2009 (TreeAge Software, Williamstown, MA), a decision analytic software, a model was built to compare 4 workplace influenza vaccination program alternatives as follows: (1) no vaccination clinic; (2) a clinic offering TIV only (inactivated vaccine clinic); (3) a clinic with an advertised choice of TIV or LAIV (vaccine choice clinic); or (4) a clinic with a choice of TIV or LAIV, an increased level of advertising, and a $5 incentive for each vaccinee (choice plus incentive clinic).14 Healthy, nonpregnant adults ages 18 to 49 years were eligible to receive LAIV in vaccine choice and choice plus incentive vaccination clinics (per license and Advisory Committee on Immunization Practices recommendations) while all working adults without contraindications could receive TIV. Models included all workers older than 18 years.

All analyses assumed the employer perspective, which accounted for the costs of planning and executing an on-site influenza vaccination clinic, as well as any productivity loss due to employee time in the vaccination queue; influenza-related presenteeism; or absenteeism due to illness, hospitalization, or death (with estimates based on median tenure with the firm). The cost of replacement labor and the effects of employer-sponsored vaccination on influenza transmission dynamics outside the workplace (ie, at home, places of recreation, worship, etc) were not considered in these analyses. The employer was assumed to be not responsible for costs associated with the treatment of influenza (eg, medications or insurance premiums). The time horizon for all analyses was one influenza season.

Two hypothetical workplaces were simulated in our analyses, that is, a firm of 50 employees (small firm) and a firm of 250 employees (large firm). The age composition of these populations reflected that of the general US workforce as reported by the Bureau of Labor Statistics: 67.98% ages 18 to 49 years, 27.47% ages 50 to 64 years, and 4.55% older than 65 years.1 All employees were assumed to be otherwise healthy individuals with work schedules as follows: an 8-hour workday, 5 days per week, and 48 weeks per year. Model parameters and distributions, including probabilities, costs, durations, ranges, and their respective sources, are outlined in Table 1. All costs were converted into 2011 US dollars using a 3% discount rate, as recommended by the Panel on Cost-Effectiveness in Health and Medicine.28

Table 1
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The vaccination rates associated with the three different workplace influenza vaccination strategies were used to populate the base case and provide the range used in the sensitivity analyses. Data regarding the logistics and costs of executing an on-site vaccination clinic were based on the authors' previous influenza vaccination trial in workplaces.14 An equal portion of the fixed intervention costs, including advertising costs ($13.68 for control and choice clinics, $27.36 for choice plus clinics) and a site setup fee of $85, was attributed to each employee who received vaccine, to avert bias in favor of the intervention. A throughput of 40 vaccinees per hour was assumed on the basis of a best practice case study,15 and the variable cost of staffing a clinic (hourly nurse wage) (personal communication, Passport Health, Inc.) was divided evenly among employees who accepted vaccination. The cost of vaccine (TIV or LAIV), cost of incentive ($5 per vaccinee in choice plus incentive clinics), and cost of lost productivity for time in the vaccination queue also contributed to the total cost of the intervention.

Graphic representations of the model can be seen in Figs 1 and 2. The base tree shown in Fig. 1 represents the decision as to which type of vaccination clinic is offered. This study, based on a workplace trial, addresses vaccinations given only at the workplace. Thus, when a clinic was offered, each employee was assigned a probability of accepting or rejecting vaccination, which was zero at firms without worksite-based vaccination clinics. The impact of minor vaccine adverse effects on productivity was assumed to be negligible and excluded from the model in the interest of parsimony. Each vaccinee also had a 0.50% probability of more-severe adverse effects that resulted in lost productivity. Each employee had a probability of developing no influenza, asymptomatic influenza, or symptomatic influenza, as shown in Fig. 2, the influenza outcomes subtree. An employee's risk of contracting influenza depended on whether he or she accepted vaccination and the effectiveness of the vaccine chosen (TIV or LAIV). Three sets of vaccine effectiveness values were used: (1) equal effectiveness for TIV and LAIV of 70% (range, 60% to 80%)2; (2) equal effectiveness for TIV and LAIV of 59% (range, 49% to 69%)20; and (3) unequal effectiveness of 73% (range, 54% to 84%) for TIV and 62% (range, 45% to 73%) for LAIV.21

Figure 1
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Figure 2
Figure 2
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For the purposes of this analysis, 100% work attendance and survival were assumed for all individuals without influenza or with asymptomatic illness, whereas employees with symptomatic illness had an 88.6% probability of attending some work while sick, staying home while sick, hospitalization, or some combination thereof.19 Each symptomatic employee was assigned the following: a total duration of illness, days worked while sick but not significantly impaired, days worked with severe illness (accruing presenteeism-related costs), and days of absenteeism (difference between days of illness and days of work while sick, including an adjustment factor of 5/7 for a 5-day work week). All employees who developed symptomatic disease had a probability of death due to influenza. Employees who died accrued a productivity loss equivalent to their expected earnings for the median duration of tenure at a firm (4.4 years; range, 2.3 to 6.1 years).18

Workers who developed influenza (whether symptomatic or asymptomatic) were assumed to generate secondary cases of influenza in the workplace based on the effective reproductive number (R), that is, the average number of secondary cases generated per primary case during the infectious period.29 Secondary cases were subject to the same outcomes as primary cases, including productivity losses due to presenteeism, absenteeism, hospitalization, and death.

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Analyses

Two major sets of analyses were conducted: Monte Carlo probabilistic sensitivity analyses and one-way sensitivity analyses. Monte Carlo probabilistic sensitivity analyses, which allow all input parameters to simultaneously vary across their ranges, were used to estimate the incremental cost and total cost for each of the following strategy comparisons (ranked from higher cost to lower cost): inactivated vaccine clinic versus no vaccination clinic, vaccine choice clinic versus inactivated vaccine clinic, and choice plus incentive clinic versus vaccine choice clinic. Calculations were based on the average costs (both intervention- and disease-related) for 1000 individuals across 1000 iterations, or 1 million total outcomes. Distributions were sampled once per trial during probabilistic sensitivity analyses to simulate individual variability. One-way sensitivity analyses were conducted for key model variables using the ranges delineated in Table 1 to identify the input parameters with substantial influence on the incremental value of workplace vaccination clinics. In these analyses, the parameter of interest was varied across its range, whereas all other variables and distributions assumed their expected values. All positive dollar values indicate a net cost to the employer, whereas negative dollar values represent net cost savings.

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RESULTS

Overall Cost to Employer

For firms without an on-site vaccination program, all costs were due to estimated influenza-attributable burden, that is, presenteeism, absenteeism, hospitalization, and death. Across a spectrum of effectiveness and transmissibility scenarios, estimated median costs ranged from $3151 to $3870 for a firm of 50 employees and from $15,485 to $19,209 for a firm of 250 employees. Overall costs to both small and large firms decreased for all intervention strategies compared with no vaccination clinic, despite the additional costs of the intervention (eg, advertising, offering a choice of TIV or LAIV, and an incentive for vaccination). Variation among interventions was minimal (Table 2).

Table 2
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Figures 3A and 3B, depicting one scenario each for a small and large firm (equal TIV and LAIV effectiveness at 70%), demonstrate the relative distribution of the overall costs for no clinic and the three types of vaccination clinics. When there is no vaccination clinic, costs are higher than for any type of clinic and all costs are attributable to disease burden. The proportion of total cost attributable to influenza decreases as the cost of intervention increases, but increases as transmissibility estimates (R) increase and more secondary cases develop (latter data not shown).

Figure 3
Figure 3
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Incremental Cost of Worksite Vaccination Assuming Equal Effectiveness of TIV and LAIV

Table 3 shows the incremental cost per employee, regardless of vaccination status, for comparisons of the intervention strategies. In a firm of 50 with R = 1.0 and scenario of equal TIV and LAIV effectiveness (70%), sponsoring an inactivated vaccine clinic compared with no vaccination clinic yielded the greatest per employee cost savings (−$4.71), with a small additional saving for the vaccine choice clinic versus inactivated vaccine clinic (−$1.26), and a modest increase in cost to add an incentive in the choice plus incentive clinic ($2.25). A similar trend was observed for larger firms (250 employees).

Table 3
Table 3
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When TIV and LAIV effectiveness were assumed to be equal, but lower (59%), the inactivated vaccine clinic versus no clinic was most cost-saving, but the incremental cost savings were lower than those realized for either the previous scenario or the subsequent one testing unequal effectiveness of the two vaccine types (Table 3, middle).

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Incremental Cost of Worksite Vaccination Assuming Unequal Effectiveness of TIV and LAIV

In the scenario of discrepant TIV and LAIV effectiveness (73% and 62%, respectively) with R = 1.0 and a firm of 50 employees, the median incremental cost per employee was again cost-saving for an inactivated vaccine clinic compared with no vaccination clinic (−$4.65), slightly more cost-saving for the vaccine choice clinic versus the inactivated vaccine clinic (−$0.87), and modestly more costly for a choice plus incentive clinic compared with a vaccine choice clinic ($2.26). In a firm of 250 employees, lower costs and a similar trend were observed (Table 3, bottom).

Thus, the greatest incremental value is realized by offering an inactivated vaccine clinic. Higher vaccination rates and additional savings can be achieved by offering a choice of TIV or LAIV to eligible employees, despite the higher cost of LAIV vaccine. Moreover, a $5.00 incentive and cost of increased advertising result in a low incremental cost of a choice plus incentive clinic (compared with a vaccine choice clinic): $0.04 to $2.55. This strategy has been shown to increase vaccination rates. Additional cost savings of employer-sponsored influenza vaccination programs can be realized by increasing employee vaccination rates. For example, in small firms, for each percentage point increase in vaccination rate, additional savings ranged from $15.69 to $25.49. In large firms, the savings were greater, ranging from $26.47 to $31.28 for each percentage point improvement in vaccination rate.

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One-Way Sensitivity Analyses

To determine which factors affected costs the most, one-way sensitivity analyses were conducted and are presented in tornado diagrams (Figs. 4A–F). These analyses indicated that the parameter with the greatest effect on the incremental cost of worksite influenza vaccination programs is the hourly wage of employees. Higher employee salaries were associated with a lower (more cost saving) incremental cost per employee regardless of firm size in workplaces that offered vaccination clinics. Other key drivers of incremental value (in decreasing order of influence) included percentage of employees with symptomatic illness, time required for vaccination, vaccine effectiveness, the number of secondary cases generated, and vaccine cost.

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DISCUSSION

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In all scenarios, offering some type of employer-sponsored vaccination clinic was less expensive than the lost productivity resulting from not offering an influenza vaccination clinic. Savings will vary directly with the hourly wages of employees;11 thus, actual savings will vary with the type and size of the business. The estimated annual cost of lost productivity (absenteeism or presenteeism) due to influenza disease exceeded $3000 for small firms; whereas large firms with 250 employees accrued more than $15,000 of influenza-attributable productivity loss, contributing to the estimated $6.2 billion in lost productivity across the United States each year.3,4

Factors that increased incremental net benefit per employee of employer-sponsored influenza vaccination clinics included increased influenza transmissibility, increased vaccine effectiveness, larger firm size, and offering a choice of influenza vaccine type. Firm size is an important consideration for planning and executing worksite influenza vaccination clinics. Fixed intervention costs such as electronic advertising and clinic setup do not appreciably change with firm size, although variable costs differ. The cost of staffing a vaccination clinic is typically based on a fixed hourly rate and an estimated hourly vaccinee throughput. For example, whether 10 or 40 employees are vaccinated, an hour of nurse time (given a throughput of 30 to 50 vaccinees per hour) is required. In a firm of 250 employees, vaccination throughput is an important factor as a clinic could require 5 to 9 hours of nurse staffing. In addition, the potential for a cascade of influenza cases is higher in larger firms, particularly when employees work in close proximity; therefore, preventing influenza disease is a greater concern in these firms to maintain adequate staffing levels and ensure business continuity.30,31

Although annual influenza vaccination programs have been shown to lower direct and indirect employer costs and are considered a cost-effective approach to preventing influenza,32,33 vaccination rates among working adults remain low. Therefore, the decision to offer a worksite vaccination clinic should be considered the first step toward preventing influenza and averting influenza-attributable costs; the second, and critical, step is to ensure a high vaccination rate. In a survey of individuals participating in a workplace vaccination trial, employees reported cost and convenience as two key factors in their decision to get vaccinated. Offering an employer-sponsored worksite vaccination clinic addresses both economic and convenience concerns.3436 Recent studies have examined different approaches to addressing other barriers to influenza vaccine in the working adult population. Some employees have reported that they would not have been vaccinated if only inactivated vaccine were available.37 In a direct comparison of costs of employer-sponsored influenza vaccination clinics, reported cost savings were somewhat less for LAIV than for TIV11; however, offering a choice of vaccines modestly increased cost savings over inactivated vaccine–only clinics in our study.

Use of incentives involves trade-offs. In almost all scenarios in our analyses, incentives were less costly than no vaccination but more costly than simple choice of TIV or LAIV or offering only TIV; yet, incentives are associated with higher vaccination rates.38 In employer-sponsored non–health care businesses, vaccination rates of 46% (ages 18 to 49 years) and 70% (older than 50 years) were achieved by increasing the intensity of advertising, promoting a choice of TIV or LAIV vaccine, and offering a $5 incentive.14 Thus, offering a choice of vaccine type, increased advertising, employee education, and incentives can be used to help to promote influenza vaccine uptake among employees. Furthermore, a firm's decision to offer an influenza vaccination clinic is more complex than a simple return on investment calculation. Worksite influenza vaccination clinics not only prevent influenza cases and reduce consequent productivity loss but also provide employers an opportunity to promote goodwill, engage employees in health promotion efforts, and establish the habit of annual influenza vaccination.37,38

This analysis is timely and relevant, owing to the substantial burden of lost productivity due to influenza and the recent expansion of the Advisory Committee on Immunization Practices guidelines to include all individuals older than 6 months for annual influenza vaccination.2 Strengths of this analysis include the use of (1) data from a published, prospective worksite vaccination trial; (2) multiple scenarios including a range of influenza transmissibility; (3) firms of both small and large sizes; (4) moderate assumptions; and (5) probabilistic sensitivity analyses to capture the effects of parameter variability.

The limitations of this study are consistent with other infectious disease modeling exercises including uncertainty in parameter values such as vaccine effectiveness, which is a subject of international debate.39 We chose to model 3 vaccine effectiveness scenarios and explored the influence of these values with one-way and probabilistic sensitivity analyses. The results of these analyses may not be generalizable to all employees and workplaces because of variations in hourly wages, number of employees, and costs (fixed or variable) of hosting a workplace vaccination clinic. Workplaces with fewer than 50 employees were not examined; firms should consider the tradeoff between fixed and variable costs when deciding if on-site vaccination clinics are of value. Vaccinations administered outside the workplace were not accounted for because (1) these costs are not directly borne by the employer; (2) the baseline trial on which these analyses were based only addressed worksite vaccinations14; and (3) a large percentage of vaccinations of working-age adults are given at worksites. Employer-sponsored immunization programs that increase vaccine uptake may lead to correspondingly larger reductions in disease rates and less productivity loss due to influenza, whereas programs that result in lower vaccination rates may have less impact.

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CONCLUSIONS

Employer-sponsored workplace vaccination is a cost-saving intervention with the potential to reduce the burden of influenza disease and its accompanying lost productivity in both small and large firms. Offering vaccine choice, with or without incentives, may lead to higher vaccination rates, reduced disease transmission, and additional cost savings under many scenarios.

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ACKNOWLEDGMENTS

The authors thank Dr Kenneth J. Smith, Division of General Internal Medicine at the University of Pittsburgh; Kristina M. Bacon, Public Health Computational and Operations Research at the University of Pittsburgh; and Dr Seth Toback at MedImmune, LLC.

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REFERENCES

1. US Bureau of Labor Statistics. Employment Status of the Civilian Noninstitutional Population by Age, Sex, and Race. Washington, DC: US Department of Labor; 2010. Available at: http://www.bls.gov/cps/cpsaat3.pdf. Accessed March 28, 2011.

2. Fiore AE, Uyeki TM, Broder K, et al. Prevention and control of influenza with vaccines: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep. 2010;59:1–62.

3. Molinari NA, Ortega-Sanchez IR, Messonnier ML, et al. The annual impact of seasonal influenza in the US: measuring disease burden and costs. Vaccine. 2007;25:5086–5096.

4. Adams PF, Hendershot GE, Marano MA. Current estimates from the National Health Interview Survey, 1996. Vital Health Stat 10. 1999;200:1–203.

5. American Management Association. AMA 2004 Survey on Health and Wellness Programs. Published November 22, 2004. Available at: http://www.amanet.org/training/whitepapers/2004-Survey-on-Health-and-Wellness-Programs-14.aspx. Accessed August 14, 2012.

6. Kennedy ED, Santibanez TA, Bryan LN, et al. Place of influenza vaccination among adults—United States, 2010–11 influenza season [Reprinted from MMWR 2011;60:781–785]. J Am Med Assoc. 2011;306:820–822.

7. Levin-Epstein J. Presenteeism and Paid Sick Days. Washington, DC: Center for Law and Social Policy; 2005. Available at: http://www.clasp.org/admin/site/publications/files/0212.pdf. Accessed May 2, 2012.

8. Rothberg MB, Rose DN. Vaccination versus treatment of influenza in working adults: a cost-effectiveness analysis. Am J Med. 2005;118:68–77.

9. Prosser LA, O'Brien MA, Molinari NA, et al. Non-traditional settings for influenza vaccination of adults: costs and cost effectiveness. Pharmacoeconomics. 2008;26:163–178.

10. Nichol KL, Mallon KP, Mendelman PM. Cost benefit of influenza vaccination in healthy, working adults: an economic analysis based on the results of a clinical trial of trivalent live attenuated influenza virus vaccine. Vaccine. 2003;21:2207–2217.

11. Lee BY, Bailey RR, Wiringa AE, et al. Economics of employer-sponsored workplace vaccination to prevent pandemic and seasonal influenza. Vaccine. 2010;28:5952–5959.

12. Health NBGo. Quick survey: on-site flu vaccinations—8/25/08. 2008. Available at: http://www.businessgrouphealth.org/publications/index.cfm.

13. D'Heilly SJ, Nichol KL. Work-site–based influenza vaccination in healthcare and non-healthcare settings. Infect Control Hosp Epidemiol. 2004;25:941–945.

14. Nowalk MP, Lin CJ, Toback SL, et al. Improving influenza vaccination rates in the workplace: a randomized trial. Am J Prev Med. 2010;38:237–246.

15. National Foundation for Infectious Diseases. Improving Influenza Vaccination Rates in Health Care Workers: Strategies to Increase Protection for Workers and Patients. Bethesda, MD: National Foundation for Infectious Diseases; 2004.

16. US Centers for Disease Control and Prevention. Possible Side-Effects From Vaccines. Atlanta, GA: Centers for Disease Control and Prevention; 2011; Also available at: http://www.cdc.gov/vaccines/vac-gen/side-effects.htm. Accessed March 28, 2011.
17. US Bureau of Labor Statistics. Occupational Employment and Wages—May 2009. Washington, DC: US Department of Labor; 2010. USDL-10–0646. Also available at: http://www.bls.gov/news.release/archives/ocwage_05142010.pdf. Accessed March 29, 2012.
18. US Bureau of Labor Statistics. Employee Tenure in 2010. Washington, DC: US Department of Labor; 2010. USDL-10–1278. Available at: http://www.bls.gov/news.release/pdf/tenure.pdf. Accessed March 28, 2012.

19. Rousculp MD, Johnston SS, Palmer LA, Chu BC, Mahadevia PJ, Nichol KL. Attending work while sick: implication of flexible sick leave policies. J Occup Environ Med. 2010;52:1009–1013.

20. Osterholm MT, Kelley NS, Sommer A, Belongia EA. Efficacy and effectiveness of influenza vaccines: a systematic review and meta-analysis. Lancet Infect Dis. 2012;12:36–44.

21. Jefferson T, Di Pietrantonj C, Rivetti A, Bawazeer GA, Al-Ansary LA, Ferroni E. Vaccines for preventing influenza in healthy adults. Cochrane Database Syst Rev. 2010;(7):CD001269.

22. Ferguson NM, Cummings DA, Fraser C, Cajka JC, Cooley PC, Burke DS. Strategies for mitigating an influenza pandemic. Nature. 2006;442:448–452.

23. Ling LM, Chow AL, Lye DC, et al. Effects of early oseltamivir therapy on viral shedding in 2009 pandemic influenza A (H1N1) virus infection. Clin Infect Dis. 2010;50:963–969.

24. Patrozou E, Mermel LA. Does influenza transmission occur from asymptomatic infection or prior to symptom onset? Public Health Rep. 2009;124:193–196.
25. Lau LL, Cowling BJ, Fang VJ, et al. Viral shedding and clinical illness in naturally acquired influenza virus infections. J Infect Dis. 2010;201:1509–1516.

26. Carrat F, Vergu E, Ferguson NM, et al. Time lines of infection and disease in human influenza: a review of volunteer challenge studies. Am J Epidemiol. 2008;167:775–785.

27. LaForce FM, Nichol KL, Cox NJ. Influenza: virology, epidemiology, disease, and prevention. Am J Prev Med. 1994;10(suppl):31–44.

28. Gold MR, Siegel JE, Russel LB, Wesinstein MC. Cost-Effectiveness in Health and Medicine. New York, NY: Oxford University Press; 1996.

29. UC Berkeley School of Public Health Center for Infectious Disease Preparedness. Concepts for the prevention and control of microbial threats. 2006; Available at: http://www.idready.org/slides/01epiconceptsII-notes.pdf. Accessed June 19, 2011.

30. Palmer LA, Rousculp MD, Johnston SS, Mahadevia PJ, Nichol KL. Effect of influenza-like illness and other wintertime respiratory illnesses on worker productivity: the child and household influenza-illness and employee function (CHIEF) study. Vaccine. 2010;28:5049–5056.

31. Keech M, Beardsworth P. The impact of influenza on working days lost: a review of the literature. Pharmacoeconomics. 2008;26:911–924.

32. Greenbaum E, Meinert E. Vaccinating Against the Flu: A Business Case. Washington, DC: National Business Group on Health Center for Prevention and Health Services; 2010. Available at: http://www.businessgrouphealth.org/pdfs/Final%20Proof%20-%20Seasonal%20Influenza.pdf. Accessed March 28, 2011.

33. Partnership for Prevention. Give Productivity a Shot in the Arm: How Influenza Immunization Can Enhance Your Bottom Line. Washington, DC: Partnership for Prevention; 2011. Also available at: http://prevent.org/flu. Accessed May 4, 2012.

34. Strunk C. Innovative workplace influenza program: boosting employee immunization rates. AAOHN J. 2005;53:432–437.

35. Lester RT, McGeer A, Tomlinson G, Detsky AS. Use of, effectiveness of, and attitudes regarding influenza vaccine among house staff. Infect Control Hosp Epidemiol. 2003;24:839–844.

36. Lee BY, Mehrotra A, Burns RM, Harris KM. Alternative vaccination locations: who uses them and can they increase flu vaccination rates? Vaccine. 2009;27:4252–4256.

37. Lin CJ, Nowalk MP, Toback SL, et al. Importance of vaccination habit and vaccine choice on influenza vaccination among healthy working adults. Vaccine. 2010;28:7706–7712.

38. Nowalk MP, Lin CJ, Zimmerman RK, et al. Establish the habit: influenza vaccination for health care personnel. J Healthc Qual. 2010;32:35–42.

39. Ambrose CS, Levin MJ, Belshe RB. The relative efficacy of trivalent live attenuated and inactivated influenza vaccines in children and adults. Influenza Other Respi Viruses. 2011;5:67–75.

©2012The American College of Occupational and Environmental Medicine

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