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Cost-Effectiveness of a Vaccine to Prevent Herpes Zoster and Postherpetic Neuralgia in Older Adults

  1. Michael B. Rothberg1,2,
  2. Anunta Virapongse1,2, and
  3. Kenneth J. Smith3
  1. 1Division of General Medicine and Geriatrics, Department of Medicine, Baystate Medical Center, Springfield
  2. 2Tufts University School of Medicine, Boston, Massachusetts
  3. 3Division of General Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
  1. Reprints or correspondence: Dr. Michael Rothberg, Div. of General Medicine and Geriatrics, Baystate Medical Center, 759 Chestnut St., Springfield, MA 01199 (Michael.Rothberg{at}bhs.org).
 
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Abstract

Background.A vaccine to prevent herpes zoster was recently approved by the United States Food and Drug Administration. We sought to determine the cost-effectiveness of this vaccine for different age groups.

Methods.We constructed a cost-effectiveness model, based on the Shingles Prevention Study, to compare varicella zoster vaccination with usual care for healthy adults aged >60 years. Outcomes included cost in 2005 US dollars and quality-adjusted life expectancy. Costs and natural history data were drawn from the published literature; vaccine efficacy was assumed to persist for 10 years.

Results.For the base case analysis, compared with usual care, vaccination increased quality-adjusted life expectancy by 0.0007–0.0024 quality-adjusted life years per person, depending on age at vaccination and sex. These increases came almost exclusively as a result of prevention of acute pain associated with herpes zoster and postherpetic neuralgia. Vaccination also increased costs by $94–$135 per person, compared with no vaccination. The incremental cost-effectiveness ranged from $44,000 per quality-adjusted life year saved for a 70-year-old woman to $191,000 per quality-adjusted life year saved for an 80-year-old man. For the sensitivity analysis, the decision was most sensitive to vaccine cost. At a cost of $46 per dose, vaccination cost <$50,000 per quality-adjusted life year saved for all adults >60 years of age. Other variables related to the vaccine (duration, efficacy, and adverse effects), postherpetic neuralgia (incidence, duration, and utility), herpes zoster (incidence and severity), and the discount rate all affected the cost-effectiveness ratio by >20%.

Conclusions.The cost-effectiveness of the varicella zoster vaccine varies substantially with patient age and often exceeds $100,000 per quality-adjusted life year saved. Age should be considered in vaccine recommendations.

Herpes zoster (“shingles”) is a dermatomal neurocutaneous disease caused by reactivation of the varicella zoster virus. The lifetime risk of herpes zoster ranges from 10% to 30% [1, 2], and the severity of both the disease and its sequelae increase with age [2]. Because it causes acute burning pain, herpes zoster can seriously impair physical, social, and emotional functioning [2–4]. Acute herpes zoster has been estimated to cost >$400 per case in physician's fees, antiviral therapy, and lost wages [5]; the total cost of herpes zoster–related hospitalizations in 1 year exceeded $8 million in Connecticut alone [6]. In addition, 10%–70% of patients with herpes zoster develop postherpetic neuralgia (PHN), which persists for >1 year in up to one-half of patients >55 years of age [4, 7], at a cost exceeding $500 per patient [8].

Antiviral therapy is cost-effective for decreasing the symptoms of herpes zoster [9], and it has been shown to reduce the duration [10], but not the incidence [1], of PHN. Unfortunately, topical analgesics, opioids, tricyclic antidepressants, nerve blocks, neuroactive drugs, and steroids all have limited success in treating the chronic and often debilitating pain associated with the disease [1, 11].

The Shingles Prevention Study (SPS) [12] demonstrated that live attenuated Oka/Merck varicella zoster vaccine protected against herpes zoster and PHN and reduced the symptoms of acute herpes zoster. Although the vaccine is effective, its cost-effectiveness has been debated. Because herpes zoster incidence varies by age and sex, the cost-effectiveness of the vaccine should not be uniform for all patients >60 years of age (the SPS's target population). Moreover, the SPS lasted only 4 years, so the vaccine's long-term efficacy—a potentially important determinant of cost-effectiveness—will not be known for some time. We examined the pharmacoeconomics of the varicella zoster vaccine using a decision analytic model to explore a variety of patient and vaccine scenarios.

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Methods

We constructed a Markov model [13] using standard computer software (Decision Maker software, version 7.07; Pratt Medical Group) to compare the cost-effectiveness of vaccination with the varicella zoster vaccine with no vaccination for healthy immunocompetent adults >60 years of age. The study was conducted from a societal perspective. Costs (expressed in 2005 US dollars) and utilities (expressed in quality-adjusted life years [QALYs]) were both discounted at 3% annually.

The entire cohort begins in the unvaccinated state, with individuals undergoing vaccination at the beginning of the first year. For each year, an age- and sex-specific underlying attack rate is applied to calculate the number of cases, major complications, and deaths due to herpes zoster. Vaccinated individuals experience a decrease in cases, complications, burden of illness, PHN, and death proportional to vaccine efficacy, which first wanes and then ceases at the maximal duration. Patients experiencing herpes zoster or its complications incur both costs and utility decrements.

In addition to the decision model, we analyzed the cost-effectiveness of the vaccine during the SPS, assuming that all costs and benefits accrued within the study period (with the exception of PHN, which could extend for up to 10 years). We calculated the cost of vaccination and then subtracted the savings from avoiding herpes zoster and PHN. We also calculated the difference in quality-adjusted life expectancy by assigning utility values to avoided cases of herpes zoster and PHN on the basis of our model inputs.

Data and Assumptions

Baseline estimates and ranges for sensitivity analyses are provided in table 1.

Figure 1
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Figure 1

Cost-effectiveness of vaccination against herpes zoster for 5 different age groups, stratified by sex. QALY, quality-adjusted life year.

Figure 2
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Figure 2

Cost-effectiveness of vaccination against herpes zoster as a function of vaccine cost. QALY, quality-adjusted life year.

Figure 3
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Figure 3

Cost-effectiveness of vaccination against herpes zoster in women as a function of duration of vaccine efficacy. Curves for men (not shown) are similar, but they shift upwards. QALY, quality-adjusted life year.

Figure 4
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Figure 4

Two-way sensitivity analysis of the probability and utility of postherpetic neuralgia. The x-axis shows the rate of postherpetic neuralgia among patients with herpes zoster aged 60–69 years and, in parentheses, among patients with herpes zoster aged ⩾70 years. The curves represent a $50,000-per-quality-adjusted-life-year (QALY) threshold for 3 different groups of patients. Combinations above and to the left of each curve cost >$50,000 per QALY. Combinations below and to the right of each curve cost ⩽$50,000 per QALY. Other patient groups did not meet the threshold within the range displayed.

Table 1
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Table 1

Baseline values for the decision model and ranges used in sensitivity analysis.

Zoster incidence and complications.The model incorporates age- and sex-specific incidence from the largest observational cohort study [14]. Rates were similar to those published 10 years earlier [35] and to rates observed in the SPS for subjects ⩾70 years of age, but they were lower than those observed for subjects <70 years of age [12]. Age-specific burden of illness in the first 6 months following infection and the rate of PHN (defined as pain persisting 3 months after the onset of illness) were based on the SPS [12]. Duration of PHN [7, 22] and age-specific rates for complications not reported in the SPS were drawn from observational studies [15, 36] and government databases [6, 20, 21]. Complications included death, hospitalization for disseminated herpes zoster or herpes zoster meningitis, ocular involvement and monocular blindness, and herpes zoster oticus and monaural deafness.

Vaccine efficacy and adverse effects.The SPS reported 3 efficacy measures, stratified by age: herpes zoster incidence, burden of illness (BOI), and PHN incidence [12]. BOI and PHN efficacy were reported for the entire population, not just for those who developed herpes zoster; thus, these measures incorporated the decreasing herpes zoster incidence—in effect, double counting. To see if there was efficacy beyond the decrease in herpes zoster incidence, we calculated the efficacy per case of herpes zoster by dividing the cases of PHN and the burden of illness scores by the number of cases of herpes zoster illness.

Efficacy in decreasing herpes zoster incidence varied with age, from 65% among subjects aged 59–64 years to 8% in subjects aged ⩾85 years. Vaccination also appeared to prevent PHN during the first year following vaccination, but it had no statistically significant additional efficacy in subsequent years (table 2). Moreover, this apparent efficacy was due to placebo recipients experiencing PHN at a significantly higher rate during the year following vaccination, relative to subsequent years, rather than to any reduction in PHN among vaccinees. We therefore assumed no reduction in PHN beyond that afforded by reducing the incidence of herpes zoster illness. In contrast, the vaccine demonstrated efficacy in reducing the severity per case in patients aged ⩾70 years (BOI score, 225 vs. 160 in the placebo and vaccination groups), but not in patients aged <70 years (BOI score, 134 vs. 128 in the placebo and vaccination groups).

Table 2
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Table 2

Efficacy of vaccine in preventing postherpetic neuralgia (PHN) in the Shingles Prevention Study.

In their US Food and Drug Administration briefing, the manufacturer of the vaccine provided data for each of the 3 efficacy measures, stratified by years after vaccination [23]. Efficacy waned in the first year after vaccination and then appeared to level off, but there were only 4 data points (1 for each year of the trial). We fit a declining logarithmic function for efficacy against zoster incidence (y = -0.1018 ln(x) + 0.5903; R2 = .56) and then calculated age-specific efficacy for each year using age-specific ORs derived from US Food and Drug Administration data. In sensitivity analysis, we tested other functions, ranging from no decrease after year 4 to complete lack of efficacy following the study period. We assumed no decrease in efficacy for decreasing severity of illness per case.

The most common adverse effect was arm soreness, but 0.7% of vaccinees experienced a “serious” reaction not experienced by participants who received placebo (95% CI, 0.1%–1.3%). In the absence of any other details, we assumed that serious reactions would be equivalent to spending 3 days in the hospital.

Utilities.SPS participants used the worst-pain component of the herpes zoster brief pain inventory to record their pain daily for up to 182 days, generating an area under the pain curve (BOI score range, 0–1820). We transformed BOI scores into utilities on the basis of results of another study [27] that compared the area under the curve of the worst-pain component of the herpes zoster brief pain inventory and the EuroQOL-5D, a validated measure of patient utilities [37]. In that study, herpes zoster brief pain inventory scores over 35 days were linearly correlated with utilities (utility = -0.1001 × BOI score + 95.767, R2 = .95). We multiplied average BOI scores from the vaccine trial by this formula and then multiplied by 365/35 to calculate the number of QALYs lost. The utility for mild, moderate, and severe PHN was based on a survey of PHN involving 385 elderly patients [26]. The proportion of patients experiencing mild, moderate, and severe symptoms came from the only population-based study reporting severity at 1 year [7]. All utilities were adjusted for age [38].

Costs.At least 7 economic analyses have measured costs associated with herpes zoster or PHN [5, 8, 31–34, 39]. We chose our direct cost estimate for acute herpes zoster illness from the largest of these [5] but tested the results of all trials in sensitivity analysis. Age-specific indirect costs, primarily patient and caregiver lost wages, came from a prospective population-based study [31]. The costs of PHN [8, 39] and ocular complications of herpes ophthalmicus [5] were based on antiviral trials. The cost of treating herpes oticus included an initial consult, audiometry, treatment with prednisone, and a follow-up visit. Hospitalization costs came from the Healthcare Utilization Project Web site [21], using national cost-to-charge ratios. Vaccine costs assumed the purchase price for a 10-pack of vaccine [29], plus 5 min of a nurse's time for vaccination [30]. We did not assign a cost to adverse effects of the vaccine. Costs were updated to 2005 US dollars [40].

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Results

Base Case Analysis

On the basis of the results of the SPS, without modeling vaccine efficacy beyond the study period or discounting, the cost to vaccinate the entire study population against herpes zoster was $2.9 million, which prevented 327 cases of herpes zoster and 53 cases of PHN and extended quality-adjusted life expectancy by 22.4 years (71% of which came from preventing PHN that lasted >6 months) (table 3). Savings attributable to preventing herpes zoster and PHN offset 12% of the cost of vaccination. The cost per QALY gained by vaccination ranged from $201,000 for patients aged 60–69 years to $75,000 for patients aged ⩾70 years.

Table 3
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Table 3

Incremental cost-effectiveness of varicella zoster vaccine based on 4 years of the Shingles Prevention Study [12].

In the decision model, we assumed that vaccine efficacy persisted beyond the study period and we considered healthy men and women of 3 different ages (table 4). At all ages, vaccination resulted in the greatest quality-adjusted life expectancy. Overall benefits (range, 0.0007–0.0024 QALYs per person) came almost exclusively from improvements in quality of life. Depending on patient age, 50%–65% of the difference in quality-adjusted life expectancy was attributable to preventing PHN, whereas 35%–50% came from preventing acute herpes zoster. The vaccine was less effective in reducing PHN in our analysis than in the SPS, because we did not model a reduction in PHN beyond the reduction in herpes zoster incidence. Reductions in hospitalizations and mortality accounted for <5% of the vaccine benefit, even in the oldest age group.

Table 4
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Table 4

Costs, mean life expectancy, and incremental cost-effectiveness of varicella zoster vaccine, stratified by age at time of vaccination and sex.

Vaccination increased total health expenditures in all groups by $94–$135 per person, compared with no vaccination. Incremental costs increased with age, because productivity gains associated with preventing acute herpes zoster partially offset the cost of the vaccine for younger patients. The incremental cost to extend life by 1 QALY ranged from $44,000 for a 70-year-old woman to $191,000 for an 80-year-old man. Disease incidence increased with age, but vaccine efficacy fell, producing a U-shaped curve for cost-effectiveness (figure 1). As a result, vaccination was most cost-effective for patients aged 70 years and, at every age, vaccination was more cost-effective for women than it was for men.

Sensitivity Analysis

We varied all the parameters through the ranges presented in table 1. Parameters that changed the cost-effectiveness of vaccination by ⩾20% included variables related to the vaccine (duration, cost, efficacy, and side effects), PHN (incidence, duration, and utility), herpes zoster (incidence and severity), and the discount rate.

Vaccine variables.The model was most sensitive to vaccine cost (figure 2). At a cost of $46 per dose, vaccination had an incremental cost-effectiveness ratio <$50,000 per QALY for all adults aged 60–80 years. Duration of immunity was important for younger patients, who were unlikely to develop herpes zoster immediately but who had a long life expectancy. If efficacy lasted only 6 years, the cost to vaccinate a 60-year-old patient was >$200,000 per QALY saved (figure 3), but it improved out to 25 years. For patients aged ⩾70 years, cost-effectiveness curves were flat beyond 10 years. Variation in vaccine efficacy within the 95% CI had modest effects (∼10%) on the cost-effectiveness. If, however, the vaccine was able to prevent an additional 33% of cases of herpes zoster in patients >69 years of age, the cost-effectiveness ratio for 80-year-olds would be reduced by one-half.

Disease variables.Because preventing PHN comprises the majority of the vaccine's benefit, the model was sensitive to increases in the incidence, duration, or severity of PHN. Vaccination cost <$50,000 per QALY for 70-year-old men if the utility of PHN was <0.72 and it cost <$50,000 per QALY for 60-year-old women if the utility was <0.64 and the probability exceeded 8.5% (figure 4). For 80-year-old patients, no combination of utility and probability produced a cost-effectiveness ratio below that threshold. Other sequelae were too rare to have a substantial impact.

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Discussion

This cost-effectiveness analysis demonstrates that, although the varicella zoster vaccine improved quality-adjusted life expectancy for all adults ⩾60 years of age, the benefits of vaccination were not evenly distributed. Although the vaccine is most effective for younger patients, most cases of herpes zoster and PHN occur among older patients. Consequently, vaccination is most cost-effective for patients aged 70 years. At any age, it is more cost-effective to vaccinate women than men, because women experience a disproportionate amount of herpes zoster and PHN. Although the cost-effectiveness for 70-year-old women is attractive, compared with other commonly accepted interventions, the cost-effectiveness in other groups often exceeds $100,000 per QALY, an amount that would be considered expensive. At $150 per dose, the vaccine does not appear to be cost-saving under any assumptions.

Two formal analyses have explored the cost-effectiveness of varicella zoster vaccine. Because both were conducted before vaccine pricing, neither estimates the actual cost-effectiveness of the vaccine. The first analysis, performed by Edmunds et al. [33] before the SPS, concluded that the vaccine would be cost-effective for patients aged 65 years at a cost of $148 if the vaccine was 60% effective and lasted at least 10 years. The second, conducted by Hornberger and Robertus [41] before vaccine licensure, concluded that, at a price of $50, the vaccine would have a cost-effectiveness of <$50,000 per QALY gained and, at a price of $200, would cost >$100,000 per QALY gained. Both of these conclusions are compatible with our findings. Our results diverge regarding the effects of age. Edmunds et al. [33] accurately modeled increasing incidence and morbidity of herpes zoster with age but assumed equal vaccine efficacy at all ages. Consequently, they found vaccination to be most cost-effective at age 80 years. In contrast, Hornberger and Robertus [41] correctly modeled the differential efficacy by age, but they assumed risk of PHN to be the same at all ages and thus found vaccination to be most cost-effective for patients aged 60 years. Incorporating age-related changes in both parameters, we observed a U-shaped curve for cost-effectiveness.

Both private insurers and Medicare have grappled with paying for varicella zoster vaccine [42]. There are ∼61 million Americans aged ⩾60 years. At the bulk price of $145.45 per vaccination, vaccinating all eligible Americans would cost ∼$9 billion. There is no doubt that the vaccine is effective, but would this enormous investment represent good value? The answer is yes and no. The vaccine is much more cost-effective for some recipients than for others. Vaccinating a 70-year-old woman costs the same as vaccinating a 60-year-old man, but it offers 3 times the health benefit. Using a threshold of $50,000 per QALY, only 70-year-old women would be eligible for vaccination. At a more liberal threshold of $100,000 per QALY, men aged 65–75 years and women aged 60–75 years would be eligible to receive the vaccine. By comparison, influenza virus and pneumococcus vaccination are generally cost-saving in the elderly population [43, 44], and varicella vaccine, which costs $66, appears to be cost-saving in children [45]. Less cost-effective vaccines, such as meningococcal [46] and pneumococcal [47] conjugate vaccines, have been accepted into the childhood vaccination schedule, but not all states universally cover their costs. Notably, a reduction in the cost of the varicella zoster vaccine would have a dramatic effect on the value it represents. At a price of $46, it could be universally recommended as being cost-effective and sometimes cost-saving.

Our analysis has several limitations. First, although many of our inputs were based on large studies that provided stable estimates, a few key values are based on limited information or vary widely among studies. A single study of 127 patients provided both the percentage of patients who have symptoms of PHN for >1 year and the proportion of long-standing symptoms that are mild, moderate, and severe [7]. We explored the effects of varying these inputs, but larger, long-term studies of both the probability and severity of PHN at 1 year are necessary to reliably determine the cost-effectiveness of the vaccine. Second, it is not known how long vaccine efficacy will last, and it will be at least 5 years before we know whether our 10-year assumption was correct. Measures of cell-mediated immunity show the vaccine's protection to have a half-life of 56 months [48], leaving little efficacy after 10–15 years. Third, the incidence of herpes zoster observed for subjects aged 60–69 years in the SPS was higher than that observed by Insinga et al. [14], although both are contemporaneous, multicenter studies. The discrepancy could represent underdiagnosis in the observational cohort or a recent increase in cases among younger age groups attributable to lack of boosting that followed widespread childhood vaccination against primary varicella infection [49]. Although increased herpes zoster incidence improves the cost-effectiveness of vaccination, even given a 40% increase among 60-year-old individuals, vaccination would still cost $84,000 per QALY. Finally, our estimates for the cost of PHN are based on data that is >10 years old, albeit updated to 2005 US dollars. Newer, more expensive drugs and treatments may have increased the cost and decreased the morbidity associated with PHN. Additional studies would be welcome.

Having successfully conquered many of the major infectious diseases afflicting Western countries, vaccine manufacturers have turned to rarer or less harmful diseases. As the potential number of childhood and adult vaccines mushrooms, both policy makers and payers struggle with decisions about which ones to recommend or cover. The Institute of Medicine (Washington, DC) has recommended that the Advisory Committee on Immunization Practices incorporate societal benefits and costs into its vaccine coverage decisions [50], and cost-effectiveness analysis offers one tool with which to do this [51]. Trying to pay for all available interventions, regardless of cost, strains budgets and causes inequity, because the rising cost of care forces some patients out of the health care system entirely. Considering both costs and benefits, the varicella zoster vaccine does not seem to represent a good value for all patients >60 years of age, although it may be reasonable for patients 70 years old, depending on the cost-effectiveness criterion used. Lowering the cost to that of the varicella vaccine would make it competitive with other generally accepted interventions.

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Acknowledgments

Financial support.Doris Duke Clinical Scientist Development Award (to M.B.R.).

Potential conflicts of interest.All authors: no conflicts.

  • Received October 12, 2006.
  • Revision received January 11, 2007.
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References

  1. ↵
    1. Gnann JW Jr,
    2. Whitley RJ
    . Clinical practice: herpes zoster. N Engl J Med 2002;347:340-6.
    CrossRefMedlineWeb of Science
  2. ↵
    1. Katz J,
    2. Cooper EM,
    3. Walther RR,
    4. Sweeney EW,
    5. Dworkin RH
    . Acute pain in herpes zoster and its impact on health-related quality of life. Clin Infect Dis 2004;39:342-8.
    Abstract/FREE Full Text
    1. Lydick E,
    2. Epstein R,
    3. Himmelberger D,
    4. White C
    . Herpes zoster and quality of life: a self-limited disease with severe impact. Neurology 1995;45(Suppl 8):52-3.
  4. ↵
    1. Kost R,
    2. Straus S
    . Postherpetic neuralgia—pathogenesis, treatment, and prevention. N Engl J Med 1996;335:32-42.
    CrossRefMedlineWeb of Science
  5. ↵
    1. Grant DM,
    2. Mauskopf JA,
    3. Bell L,
    4. Austin R
    . Comparison of valaciclovir and acyclovir for the treatment of herpes zoster in immunocompetent patients over 50 years of age: a cost-consequence model. Pharmacotherapy 1997;17:333-41.
    MedlineWeb of Science
  6. ↵
    1. Lin F,
    2. Hadler JL
    . Epidemiology of primary varicella and herpes zoster hospitalizations: the pre-varicella vaccine era. J Infect Dis 2000;181:1897-905.
    Abstract/FREE Full Text
  7. ↵
    1. Helgason S,
    2. Petursson G,
    3. Gudmundsson S,
    4. Sigurdsson JA
    . Prevalence of postherpetic neuralgia after a first episode of herpes zoster: prospective study with long term follow up. BMJ 2000;321:1-4.
    FREE Full Text
  8. ↵
    1. Davies L,
    2. Cossins L,
    3. Bowsher D,
    4. Drummond M
    . The cost of treatment for post-herpetic neuralgia in the UK. Pharmacoeconomics 1994;6:142-8.
    CrossRefMedlineWeb of Science
  9. ↵
    1. Smith KJ,
    2. Roberts MS
    . Cost effectiveness of newer antiviral agents for herpes zoster: is the evidence spotty? J Infect Dis 1998;178(Suppl 1):85-90.
    CrossRef
  10. ↵
    1. Jackson JL,
    2. Gibbons R,
    3. Meyer G,
    4. Inouye L
    . The effect of treating herpes zoster with oral acyclovir in preventing postherpetic neuralgia: a meta-analysis. Arch Intern Med 1997;157:909-12.
    Abstract/FREE Full Text
  11. ↵
    1. Gilden DH
    . Varicella-zoster virus vaccine—grown-ups need it, too. N Engl J Med 2005;352:2344-6.
    CrossRefMedlineWeb of Science
  12. ↵
    1. Oxman MN,
    2. Levin MJ,
    3. Johnson GR,
    4. et al
    . A vaccine to prevent herpes zoster and postherpetic neuralgia in older adults. N Engl J Med 2005;352:2271-84.
    CrossRefMedlineWeb of Science
  13. ↵
    1. Sonnenberg F,
    2. Beck J
    . Markov models in medical decision making: a practical guide. Med Decis Making 1993;13:322-38.
    Abstract/FREE Full Text
  14. ↵
    1. Insinga RP,
    2. Itzler RF,
    3. Pellissier JM,
    4. Saddier P,
    5. Nikas AA
    . The incidence of herpes zoster in a United States administrative database. J Gen Intern Med 2005;20:748-53.
    CrossRefMedlineWeb of Science
  15. ↵
    1. Galil K,
    2. Choo P,
    3. Donahue J,
    4. Platt R
    . The sequelae of herpes zoster. Arch Intern Med 1997;157:1209-13.
    Abstract/FREE Full Text
    1. Cobo L,
    2. Foulks G,
    3. Liesegang T,
    4. et al
    . Oral acyclovir in the treatment of acute herpes zoster ophthalmicus. Ophthalmology 1986;93:763-70.
    MedlineWeb of Science
    1. Colin J,
    2. Prisant O,
    3. Cochener B,
    4. Lescale O,
    5. Rolland B,
    6. Hoang-Xuan T
    . Comparison of the efficacy and safety of valaciclovir and acyclovir for the treatment of herpes zoster ophthalmicus. Ophthalmology 2000;107:1507-11.
    CrossRefMedlineWeb of Science
    1. Murakami S,
    2. Hato N,
    3. Horiuchi J,
    4. Honda N,
    5. Gyo K,
    6. Yanagihara N
    . Treatment of Ramsay Hunt syndrome with acyclovir-prednisone: significance of early diagnosis and treatment. Ann Neurol 1997;41:353-7.
    CrossRefMedlineWeb of Science
    1. Opstelten W,
    2. Mauritz JW,
    3. de Wit NJ,
    4. van Wijck AJ,
    5. Stalman WA,
    6. van Essen GA
    . Herpes zoster and postherpetic neuralgia: incidence and risk indicators using a general practice research database. Fam Pract 2002;19:471-5.
    Abstract/FREE Full Text
  20. ↵
    Centers for Disease Control and Prevention (CDC). WONDER compressed mortality file: underlying cause of death. 1999–2002. Available at: http://wonder.cdc.gov/mortSQL.html. Accessed 6 June 2006.
  21. ↵
    Agency for Healthcare Research and Quality. HCUPnet, healthcare cost and utilization project. 2003. Available at: http://www.hcupnet.ahrq.gov. Accessed 21 May 2006.
  22. ↵
    1. Hope-Simpson RE
    . Postherpetic neuralgia. J R Coll Gen Pract 1975;25:571-5.
    Medline
  23. ↵
    1. Merck M
    . Zoster vaccine live (Oka/Merck) Zostavax. FDA clinical briefing document for Merck and Co 2005. Available at: http://www.fda.gov/ohrms/dockets/ac/05/briefing/5-4198B2_1.pdf Accessed 29 March 2007.
    1. Brown MM,
    2. Brown GC,
    3. Sharma S,
    4. Busbee B,
    5. Brown H
    . Quality of life associated with unilateral and bilateral good vision. Ophthalmology 2001;108:643-7. discussion, 647-8.
    CrossRefMedlineWeb of Science
    1. Summerfield AQ,
    2. Marshall DH,
    3. Barton GR,
    4. Bloor KE
    . A cost-utility scenario analysis of bilateral cochlear implantation. Arch Otolaryngol Head Neck Surg 2002;128:1255-62.
    Abstract/FREE Full Text
  26. ↵
    1. Oster G,
    2. Harding G,
    3. Dukes E,
    4. Edelsberg J,
    5. Cleary PD
    . Pain, medication use, and health-related quality of life in older persons with postherpetic neuralgia: results from a population-based survey. J Pain 2005;6:356-63.
    CrossRefMedlineWeb of Science
  27. ↵
    1. Coplan PM,
    2. Schmader K,
    3. Nikas A,
    4. et al
    . Development of a measure of the burden of pain due to herpes zoster and postherpetic neuralgia for prevention trials: adaptation of the brief pain inventory. J Pain 2004;5:344-56.
    CrossRefMedlineWeb of Science
    1. Rothberg M,
    2. Bennish ML,
    3. Kao JS,
    4. Wong JB
    . Do the benefits of varicella vaccination outweigh the long-term risks?. A decision-analytic model for policymakers and pediatricians. Clin Infect Dis 2002;34:885-94.
    Abstract/FREE Full Text
  29. ↵
    1. Merck
    . FDA approves ZOSTAVAX, Merck's new vaccine for prevention of shingles in adults age 60 and older. Merck. 2006. Available at: http://www.merck.com/newsroom/press_releases/product/2006_0526.html. Accessed 6 June 2006.
  30. ↵
    US Bureau of Labor Statistics. Employer costs for employee compensation. 2005. Available at: http://www.bls.gov/news.release/ecec.t14.htm. Accessed 8 June 2006.
  31. ↵
    1. Scott FT,
    2. Johnson RW,
    3. Leedham-Green M,
    4. Davies E,
    5. Edmunds WJ,
    6. Breuer J
    . The burden of herpes zoster: a prospective population based study. Vaccine 2006;24:1308-14.
    CrossRefMedlineWeb of Science
    1. Gruger J,
    2. Backhouse ME
    . Economic evaluation of antiviral therapy for the treatment of herpes zoster in immunocompetent adults. Pharmacoeconomics 1997;11:262-73.
    CrossRefMedlineWeb of Science
  33. ↵
    1. Edmunds WJ,
    2. Brisson M,
    3. Rose JD
    . The epidemiology of herpes zoster and potential cost-effectiveness of vaccination in England and Wales. Vaccine 2001;19:3076-90.
    CrossRefMedlineWeb of Science
  34. ↵
    1. Paul JE,
    2. Mauskopf JA,
    3. Bell L
    . Cost-consequence models for varicella-zoster virus infections. Pharmacotherapy 1995;15:49-58.
  35. ↵
    1. Donahue J,
    2. Choo P,
    3. Manson J,
    4. Platt R
    . The incidence of herpes zoster. Arch Intern Med 1995;155:1605-9.
    Abstract/FREE Full Text
  36. ↵
    1. Ragozzino M,
    2. Melton L,
    3. Kurland L,
    4. Chu C,
    5. Perry H
    . Population-based study of herpes zoster and its sequelae. Medicine 1982;61:310-6.
    Medline
  37. ↵
    1. Brooks R
    . EuroQol: the current state of play. Health Policy 1996;37:53-72.
    CrossRefMedlineWeb of Science
  38. ↵
    1. Gold MR,
    2. Franks P,
    3. McCoy KI,
    4. Fryback DG
    . Toward consistency in cost-utility analyses: using national measures to create condition-specific values. Med Care 1998;36:778-92.
    CrossRefMedlineWeb of Science
  39. ↵
    1. Huse DM,
    2. Schainbaum S,
    3. Kirsch AJ,
    4. Tyring S
    . Economic evaluation of famciclovir in reducing the duration of postherpetic neuralgia. Am J Health Syst Pharm 1997;54:1180-4.
    Abstract/FREE Full Text
  40. ↵
    US Bureau of Labor Statistics. Consumer price index—all urban consumers. 2006. Available at: http://www.bls.gov/data/. Accessed 7 June 2006.
  41. ↵
    1. Hornberger J,
    2. Robertus K
    . Cost-effectiveness of a vaccine to prevent herpes zoster and postherpetic neuralgia in older adults. Ann Intern Med 2006;145:317-25.
    Abstract/FREE Full Text
  42. ↵
    1. Neergaard L
    . Associated Press. 2006. Experts: price may block shingles vaccine. Available at: http://www.boston.com/yourlife/health/diseases/articles/2006/09/25/experts_price_may_block_singles_vaccine/. Accessed 29 March 2007.
  43. ↵
    1. Nichol KL,
    2. Cohen GM,
    3. Nettleman MD,
    4. et al
    . The efficacy, effectiveness and cost-effectiveness of inactivated influenza virus vaccines. Vaccine 2003;21:1769-75.
    CrossRefMedlineWeb of Science
  44. ↵
    1. Sisk JE,
    2. Moskowitz AJ,
    3. Whang W,
    4. et al
    . Cost-effectiveness of vaccination against pneumococcal bacteremia among elderly people. JAMA 1997;278:1333-9.
    Abstract/FREE Full Text
  45. ↵
    1. Lieu TA,
    2. Cochi SL,
    3. Black SB,
    4. et al
    . Cost-effectiveness of a routine varicella vaccination program for US children. JAMA 1994;271:375-81.
    Abstract/FREE Full Text
  46. ↵
    1. Shepard CW,
    2. Ortega-Sanchez IR,
    3. Scott RD 2nd,
    4. Rosenstein NE
    . Cost-effectiveness of conjugate meningococcal vaccination strategies in the United States. Pediatrics 2005;115:1220-32.
    Abstract/FREE Full Text
  47. ↵
    1. Lieu TA,
    2. Ray GT,
    3. Black SB,
    4. et al
    . Projected cost-effectiveness of pneumococcal conjugate vaccination of healthy infants and young children. JAMA 2000;283:1460-8.
    Abstract/FREE Full Text
  48. ↵
    1. Levin MJ,
    2. Barber D,
    3. Goldblatt E,
    4. et al
    . Use of a live attenuated varicella vaccine to boost varicella-specific immune responses in seropositive people 55 years of age and older: duration of booster effect. J Infect Dis 1998;178(Suppl 1):109-12.
    Abstract/FREE Full Text
  49. ↵
    1. Yih WK,
    2. Brooks DR,
    3. Lett SM,
    4. et al
    . The incidence of varicella and herpes zoster in Massachusetts as measured by the Behavioral Risk Factor Surveillance System (BRFSS) during a period of increasing varicella vaccine coverage, 1998–2003. BMC Public Health 2005;5:68.
    CrossRefMedline
  50. ↵
    Institute of Medicine. Financing vaccines in the 21st century: assuring access and availability. Washington, DC: National Academcy of Sciences; 2003.
  51. ↵
    1. Davis MM
    . Varicella vaccine, cost-effectiveness analyses, and vaccination policy. JAMA 2005;294:845-6.
    FREE Full Text
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  1. Clin Infect Dis. (2007) 44 (10): 1280-1288. doi: 10.1086/514342
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