Herpes zoster-related deaths in the United States: validity of death certificates and mortality rates, 1979-2007

Death Certification: Errors and Interventions

OBJECTIVE

Death certificates are legal documents containing critical information. Despite the importance of accurate certification, errors remain common. Estimates of error prevalence vary between studies, and error classification systems are often unclear. Relatively few studies have assessed the frequency at which death certification errors occur in US hospitals, and even fewer have attempted a standardized classification of errors based on their severity. In the current study, our objective was to evaluate the frequency of death certification errors at an academic center, implement a standardized method of categorizing error severity, and analyze sources of error to better identify ways to improve death certification accuracy.

DESIGN

We retrospectively reviewed the accuracy of cause and manner of death certification at our regional academic institution for 179 cases in which autopsy was performed between 2013-2016. We compared non-pathologist physician completed death certificates with the cause and manner of death ultimately determined at autopsy.

METHODS

Errors were classified via a 5-point scale of increasing error severity. Grades I-IIc were considered minor errors, while III-V were considered severe. Sources of error were analyzed.

RESULTS

In the majority of cases (85%), death certificates contained ≥ one error, with multiple errors (51%) being more common than single (33%). The most frequent error type was Grade 1 (53%), followed by Grade III (30%), and Grade IIb (18%). The more severe Grade IV errors were seen in 23% of cases; no Grade V errors were found. No amendments were made to any death certificates following finalization of autopsy results during the study period.

CONCLUSION

This study reaffirms the importance of autopsy and autopsy pathologists in ensuring accurate and complete death certification. It also suggests that death certification errors may be more frequent than previously reported. We propose a method by which death certification errors can be classified in terms of increasing severity. By understanding the types of errors occurring on death certificates, academic institutions can work to improve certification accuracy. Better clinician education, coordination with autopsy pathologists, and implementation of a systematic approach to ensuring concordance of death certificates with autopsy results is recommended.

Cost-effectiveness of vaccination of immunocompetent older adults against herpes zoster in the Netherlands: a comparison between the adjuvanted subunit and live-attenuated vaccines

BACKGROUND

The newly registered adjuvanted herpes zoster subunit vaccine (HZ/su) has a higher efficacy than the available live-attenuated vaccine (ZVL). National decision-makers soon need to decide whether to introduce HZ/su or to prefer HZ/su above ZVL.

METHODS

Using a Markov model with a decision tree, we conducted a cost-effectiveness analysis of vaccination with HZ/su (two doses within 2 months) or zoster vaccine live (ZVL) (single dose, or single dose with a booster after 10 years) for cohorts of 50-, 60-, 70- or 80-year-olds in the Netherlands. The model was parameterized using vaccine efficacy data from randomized clinical trials and up-to-date incidence, costs and health-related quality of life data from national datasets. We used a time horizon of 15 years, and the analysis was conducted from the societal perspective.

RESULTS

At a coverage of 50%, vaccination with two doses of HZ/su was estimated to prevent 4335 to 10,896 HZ cases, depending on the cohort age. In comparison, this reduction was estimated at 400-4877 for ZVL and 427-6466 for ZVL with a booster. The maximum vaccine cost per series of HZ/su to remain cost-effective to a willingness-to-pay threshold of €20,000 per quality-adjusted life year (QALY) gained ranged from €109.09 for 70-year-olds to €63.68 for 50-year-olds. The cost-effectiveness of ZVL changed considerably by age, with corresponding maximum vaccine cost per dose ranging from €51.37 for 60-year-olds to €0.73 for 80-year-olds. Adding a ZVL booster after 10 years would require a substantial reduction of the maximum cost per dose to remain cost-effective as compared to ZVL single dose. Sensitivity analyses on the vaccine cost demonstrated that there were scenarios in which vaccination with either HZ/su (two doses), ZVL single dose or ZVL + booster could be the most cost-effective strategy.

CONCLUSIONS

A strategy with two doses of HZ/su was superior in reducing the burden of HZ as compared to a single dose or single dose + booster of ZVL. Both vaccines could potentially be cost-effective to a conventional Dutch willingness-to-pay threshold for preventive interventions. However, whether HZ/su or ZVL would be the most cost-effective alternative depends largely on the vaccine cost.

Development of adjuvanted recombinant zoster vaccine and its implications for shingles prevention

INTRODUCTION

GSK has developed a two-dose adjuvanted recombinant zoster vaccine (Shingrix, RZV) to protect people aged ≥50 years (50+) against herpes zoster (HZ) and its complications. RZV showed >90% efficacy against HZ, sustained over 4 years of follow-up, in all studied age groups.

AREAS COVERED

This article reviews the scientific rationale underlying the design of RZV; the clinical evidence demonstrating immunogenicity, safety, and efficacy in persons 50+; and the public health implications and cost-effectiveness.

EXPERT COMMENTARY

A decline in varicella zoster virus (VZV) immunity is associated with increased risk of HZ in adults 50+ and immunocompromised individuals. RZV was designed to restore levels of anti-VZV cellular and humoral immunity to prevent VZV reactivation. RZV includes the recombinant gE glycoprotein antigen, and Adjuvant System AS01_B which promotes cellular and antibody responses. In two Phase III studies in subjects aged 50+ and 70+ years, RZV efficacy against HZ compared to placebo was >90% and ≥89% against post-herpetic neuralgia (PHN). RZV is expected to dramatically impact HZ morbidity including its complications, and associated health-care costs. In the US population aged 50+ years, vaccination with RZV can be cost-effective compared to no vaccination and cost-saving compared to the currently available live-attenuated HZ vaccine (Zostavax, Merck).

Mortality risk after herpes zoster infection in end-stage renal disease patients

Background

End-stage renal disease (ESRD) patients have increased risk of developing herpes zoster (zoster) compared with the general population, but mortality risk is unknown. We assessed the risk of mortality in hospitalized ESRD patients with a diagnosis of zoster from the inpatient hospital files (as opposed to outpatient records) of the United States Renal Data System.

Methods

This study analyzed incident ESRD patients from 2006 to 2009. Based on an International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis code of zoster infection, we determined 2-year mortality following an inpatient diagnosis. Cox proportional hazards models were used to examine the association of mortality and zoster, when controlling for demographic and other clinical risk factors.

Results

Zoster was diagnosed in 2784 patients, 51% of whom died within 2 years, with a mean time to death of 8.1 months. Patients who died were more likely to be white and older, score higher on the Charlson Comorbidity Index (CCI) and have other clinical diagnoses besides CCI. Increased risk of death within 2 years was associated with older age (adjusted hazard ratio 1.03), malnutrition (1.31), bacteremia/septicemia (1.16) and increasing CCI (1.10). Zoster vaccine was administered to 27 patients, but the small number precluded analysis of its impact.

Conclusions

Mortality in ESRD patients with an inpatient zoster diagnosis is increased with older age and higher severity of clinical comorbidities. The role of zoster vaccination on mortality in this population remains to be defined.

Burden of herpes zoster in 16 selected immunocompromised populations in England: a cohort study in the Clinical Practice Research Datalink 2000-2012

OBJECTIVES

Herpes zoster (HZ) is caused by reactivation of varicella-zoster virus which remains latent in individuals after a varicella infection. It is expected that HZ will be more frequent in immunocompromised (IC) individuals than in immunocompetent (IC-free). This study assessed the incidence rate (IR) of HZ in individuals with a wide set of IC conditions and in IC-free individuals.

SETTING

A retrospective cohort study was conducted in England using data (January 2000 to March 2012) from the Clinical Practice Research Datalink with linkage to the Hospital Episodes Statistics.

PARTICIPANTS

A cohort of 621 588 individuals with 16 selected IC conditions and a gender/age-matched cohort of IC-free individuals were identified. The IC conditions included haematopoietic stem cell transplant (HSCT), solid organ transplant, malignancies, autoimmune diseases and users of immunosuppressive medications.

OUTCOMES

IR of HZ per 1000 person-years (PY) was estimated. Proportions of postherpetic neuralgia (PHN) and other HZ complications within 90 days of HZ onset were also estimated among patients with HZ. Risk factors for PHN in IC individuals with HZ were assessed by a multivariate regression model.

RESULTS

The overall IR of HZ in the IC cohort was 7.8/1000 PY (95% CI 7.7 to 7.9), increasing with age from 3.5/1000 PY (3.4-3.7) in individuals aged 18-49 years to 12.6/1000 PY (12.2-13.0) in individuals aged ≥80 years. This IR in the IC-free cohort was 6.2/1000 PY (6.1-6.3). The overall IR of HZ varied across IC conditions, ranging from 5.3 (5.1-5.5) in psoriasis to 41.7/1000 PY (35.7-48.4) in HSCT. The proportions of PHN and other HZ complications were 10.7% (10.2-11.1) and 2.9% (2.7-3.2) in the IC cohort, but 9.1% (8.7-9.5) and 2.3% (2.1-2.6) in the IC-free cohort, respectively.

CONCLUSION

IC population contributes to the public health burden of HZ in England. Vaccination might be the most preferable HZ preventive measure for the IC population.

The Potential Public Health Impact of Herpes Zoster Vaccination of People Aged ≥ 50 Years in Japan: Results of a Markov Model Analysis

INTRODUCTION

The aim of this study was to compare the public health impact of introducing two herpes zoster (HZ) vaccines into the vaccination programs for the Japanese population aged ≥ 50 years: a single-dose Varicella Vaccine Live (VVL) or a two-dose adjuvanted Recombinant Zoster Vaccine (RZV).

METHODS

A multi-cohort static Markov model was developed to follow age cohorts (50-59, 60-69, 70-79 and ≥ 80 years) over their remaining lifetime. Japan-specific data inputs for the model were obtained from Japanese data sources. Age-stratified vaccine efficacy and waning rates were based on published clinical trial data. In the base-case analysis, vaccine coverage was assumed to be 40% for both vaccines, and compliance with second-dose of the RZV vaccine was set to 95%.

RESULTS

Vaccination with RZV was projected to prevent approximately 3.3 million HZ cases, 692,000 cases of postherpetic neuralgia (PHN), and 281,000 cases of other complications, compared with the prevention of 0.8 million HZ cases, 216,000 PHN cases, and 57,000 other complications with vaccination with VVL. The number of individuals needed to vaccinate in order to prevent one HZ case ranged from 6 to 14 using RZV (depending on age and assumed second-dose compliance) and from 21 to 138 depending on age using VVL. By preventing a higher number of HZ cases and its complications, RZV vaccination led to fewer outpatient visits and hospitalizations than vaccination with VVL.

CONCLUSION

Both vaccines had a positive public health impact compared to no vaccination, but due to its higher vaccine efficacy, RZV demonstrated a superior public health impact compared with VVL.

FUNDING

GlaxoSmithKline Biologicals SA.

Duration of Antiviral Prophylaxis and Risk of Herpes Zoster among Patients Receiving Autologous Hematopoietic Stem Cell Transplants: A Retrospective, Observational Study

Introduction

There are no real-world data on antiviral prophylaxis (AP) duration and risk of herpes zoster (HZ) given AP duration in patients receiving autologous hematopoietic stem cell transplants (auto-HSCT). The objectives of this study are to describe the duration of AP and to compare incidence of HZ by AP duration in auto-HSCT patients.

Methods

This is a retrospective, observational database (Marketscan^®) study. This study included patients ≥18 years old who had auto-HSCT during 2009–2013, had chemotherapy within 60 days prior to auto-HSCT (latest chemotherapy date within the 60 days was the study enrollment date), and had continuous health plan enrollment for at least 365 days before and after the study enrollment date. AP duration was the sum of days supply of all AP prescriptions from 30 days before to 365 days after the study enrollment date. Patients were followed from the study enrollment date to the end of continuous health plan enrollment, death, or December 31, 2014 to assess HZ incidence. The Cox proportional hazards model was used to examine the association between the risk of HZ and AP duration.

Results

This study identified 1959 eligible auto-HSCT patients, of whom 93.0% were prescribed AP. Average AP duration was 220 days (SD = 122), while 200 (11%) patients had AP for ≥1 year. HZ incidence was 42.4/1000 person-years (PY) (95% CI 36.5, 49.0) for the overall auto-HSCT cohort. Among patients who received AP, duration of AP prescriptions and HZ incidence were inversely related. Compared with patients who were on AP for 1–89 days, patients with AP duration of 180–269 days [hazard ratio (HR) = 0.576, p = 0.019], 270–359 days (HR = 0.594, p = 0.023), and ≥360 days (HR = 0.309, p < 0.001) had significantly lower risk of HZ.

Conclusion

Auto-HSCT patients are at increased risk for HZ, even when prescribed AP. A safe and effective vaccine against HZ for auto-HSCT patients could be a useful adjunctive prevention strategy.

Electronic supplementary material

The online version of this article (doi:10.1007/s12325-017-0553-4) contains supplementary material, which is available to authorized users.

[Vaccines against Herpes zoster: Effectiveness, safety, and cost/benefit ratio]

CONTEXT

A vaccination against herpes zoster and its complication is available in France since June 2015. Its exact benefit for public health is still controversial and its level of protection is not optimal. All those reasons seem to suggest a low acceptation rate from general practitioners.

OBJECTIVE

To evaluate the effectiveness, the safety, and the cost/benefit ratio of the vaccination against herpes zoster in people aged 50 year or over.

DOCUMENTARY SOURCE

Systematic review in Medline and PubMed with research by key words: "herpes zoster vaccine", "zoster vaccine" and "post herpetic neuralgia vaccine".

SELECTION OF STUDIES

Randomized and observational studies published in English and French language have been selected by two readers.

RESULTS

On 1886 articles identified, 62 studies were included in this systematic review of which 21 randomized trials, 21 observational studies, and 17 medico-economic studies concerned the unadjuvanted vaccine. Considered studies showed an effectiveness of 50% against herpes zoster and 60% on post-herpetic neuralgia incidence of the unadjuvanted vaccine. Five randomized controlled studies were identified for the adjuvanted vaccine. The overall effectiveness of this vaccine was > 90% whatever the age of subjects including those over age 70 and 80. The medico-economic studies conducted in many countries have shown that vaccine policies were beneficial in individuals aged 60 years or over.

LIMITATION OF THE WORK

Most of data of effectiveness, and tolerance result from 2 large controlled studies only (SPS and ZEST) for the unadjuvanted vaccine and only one for the adjuvanted vaccine.

CONCLUSION

Despite controversy and few uncertainties, the vaccine significantly reduces herpes zoster and its complication incidence. In terms of public health objectives, it reduces the burden of the disease and has a positive medico-economic impact. Preliminary data concerning the adjuvanted vaccine, whilst very promising, are still too limited. Up to now, no group of people with particularly high risk of herpes zoster-related complication who will beneficiate the most of the vaccination has been identified yet and only an age criteria has been considered for the recommendation.

Burden of vaccine-preventable disease in adult Medicaid and commercially insured populations: analysis of claims-based databases, 2006–2010

Vaccination rates among United States (US) adults are suboptimal, resulting in morbidity, mortality, and financial burden attributable to potentially vaccine-preventable diseases (VPDs). Unadjusted annual incidence proportions of VPDs were estimated for Medicaid and commercially insured adults aged 19-64 years using 2006-2010 claims, along with age/gender-adjusted incidence proportions for 2010. In 2010, 1.6 million Medicaid adults (mean age 34 ± 12 years; 73.4% female) and 33 million commercially insured (mean age 42 ± 13 years; 52.2% female) were included. Age/gender-adjusted incidence proportions (per 100 000) in 2010 among Medicaid vs commercially insured adults for meningococcal disease were 26.2 (95% CI 22.9-29.8) vs 2.0 (1.9-2.2) (P < 0.001); hepatitis B 88.9 (82.6-95.6) vs 17.5 (17.0-17.9) (P < 0.001); pneumococcal disease 98.2 (91.7-105.1) vs 21.1 (20.7-21.6) (P < 0.001); hepatitis A 19.8 (16.9-23.1) vs 4.5 (4.3-4.7) (P < 0.001); mumps 2.1 (1.3-3.3) vs 1.4 (1.3-1.6) (P = 0.14); measles 0.3 (0.1-1.0) vs 0.3 (0.2-0.3) (P = 0.38); herpes zoster (60- to 64-year-olds only) 459 (408-515) vs 473 (466-481) (P = 0.35); varicella (19- to 39-year-olds only) 6.5 (4.8-8.5) vs 8.0 (7.5-8.5) (P = 0.12); influenza 586 (573-598) vs 633 (631-636) (P < 0.001); and pertussis 1.8 (1.1-2.8) vs 3.2 (3.0-3.4) (P < 0.001). Research is needed to fully understand the causes of the disparity of the coded incidence of some VPDs in adult Medicaid population than commercially insured adults in the US.

Herpes zoster-associated mortality in Europe: a systematic review

Background

Reactivation of latent varicella zoster virus, partly due to age-related immunosenescence and immunosuppressive conditions, results in herpes zoster (HZ) and its associated complications. The management of the most important complication, post-herpetic neuralgia (PHN), is challenging, particularly in the elderly, and is generally unsatisfactory. No previous reviews have reported the incidence of HZ-associated mortality.

Methods

We carried out a systematic literature review to identify studies and databases providing data for HZ-associated mortality in adults aged ≥50 years in Europe.

Results

We identified 12 studies: Belgium (1); France (1); Germany (1); the Netherlands (2); Portugal (1); Spain (4) and England/Wales (2) and 4 databases from Europe: France; Germany and England/Wales. The incidence was available from eight studies; it was highest in those aged ≥95 in France (19.48/100,000). In the European (WHO) database, the overall mortality ranged from 0 to >0.07/100,000. The age- and gender-specific HZ mortality rates from the other databases showed that while in younger age groups the HZ mortality rate was higher in males, in older patients the rate was much higher in women. The case fatality rate was 2 and 61/100 000 in those 45–65 and ≥65 years, respectively. A similar increase with age was seen for the hospital fatality rate; 0.6% in those 45–65 years in the UK and 7.1% in those ≥80 in Spain.

Conclusions

Although the data were sparse and heterogeneous, HZ-associated mortality clearly increases with age. In addition, the elderly who develop HZ often have underlying diseases and are at increased risk of functional decline and loss of independence. Mortality should be taken into account in health-economics models.

Incidence of herpes zoster and persistent post-zoster pain in adults with or without diabetes in the United States

We assessed association between diabetes and herpes zoster (HZ) and persistent post-zoster pain (PPZP) in adults. Among 51 million enrollees [~88 million person-years at risk], individuals with diabetes had 45% and 18% higher adjusted risk of HZ and odds of PPZP, respectively.

Background

 This study was designed to assess the association between diabetes and herpes zoster (HZ) and persistent post-zoster pain (PPZP).

Methods

 We used a United States-based, 2005–2009 retrospective observational study of medical and pharmacy claims from adults in 3 large national databases. Incidence rate ratios were used to compare HZ incidence by diabetes status. Multivariate regressions assessed the age and sex-adjusted risk of diabetes on HZ and PPZP as a function of immune competence. National projections of HZ and PPZP cases were obtained.

Results

 Among 51 million enrollees (∼88 million person-years [PYs] at risk), we identified 420 515 HZ cases. Patients with diabetes represented 8.7% of the PYs analyzed but accounted for 14.5% of the HZ cases and 20.3% of the PPZP cases. The crude incidence of HZ was 78% higher (7.96 vs 4.48 cases/1000 PY; P < .01) and the rate of PPZP was 50% higher (5.97% vs 3.93%; P < .01) in individuals with diabetes than without. Individuals with diabetes had 45% higher adjusted risk of HZ (hazard ratio [HR] = 1.45; 95% confidence intervals [CIs], 1.43–1.46) and 18% higher adjusted odds of PPZP (odds ratio = 1.18; 95% CI, 1.13–1.24). The risk of HZ associated with diabetes among immune-compromised individuals was weaker (HR = 1.10; 95% CI, 1.07–1.14) and the risk of PPZP was no longer significant. Every year, approximately 1.2 million HZ cases occur in US adults, 13% of these occur in individuals with diabetes.

Conclusions

 Diabetes is a risk factor for HZ and PPZP in the US adult population. This association is stronger in immune-competent individuals.

Systematic review of incidence and complications of herpes zoster: towards a global perspective

OBJECTIVE

The objective of this study was to characterise the incidence rates of herpes zoster (HZ), also known as shingles, and risk of complications across the world.

DESIGN

We systematically reviewed studies examining the incidence rates of HZ, temporal trends of HZ, the risk of complications including postherpetic neuralgia (PHN) and HZ-associated hospitalisation and mortality rates in the general population. The literature search was conducted using PubMed, EMBASE and the WHO library up to December 2013.

RESULTS

We included 130 studies conducted in 26 countries. The incidence rate of HZ ranged between 3 and 5/1000 person-years in North America, Europe and Asia-Pacific, based on studies using prospective surveillance, electronic medical record data or administrative data with medical record review. A temporal increase in the incidence of HZ was reported in the past several decades across seven countries, often occurring before the introduction of varicella vaccination programmes. The risk of developing PHN varied from 5% to more than 30%, depending on the type of study design, age distribution of study populations and definition. More than 30% of patients with PHN experienced persistent pain for more than 1 year. The risk of recurrence of HZ ranged from 1% to 6%, with long-term follow-up studies showing higher risk (5-6%). Hospitalisation rates ranged from 2 to 25/100 000 person-years, with higher rates among elderly populations.

CONCLUSIONS

HZ is a significant global health burden that is expected to increase as the population ages. Future research with rigorous methods is important.

Vaccine against herpes zoster

The herpes zoster vaccine is made using high doses of live attenuated varicella/zoster virus. The vaccine is well tolerated and has few adverse effects: the most common one is pain at the injection site. Complications can occur mainly in persons who had prior zoster keratitis or uveitis. The vaccine can prevent this disease with low mortality but high morbidity.

Varicella zoster vaccines and their implications for development of HSV vaccines

Live attenuated vaccines to prevent varicella and zoster have been available in the US for the past 17 years, with a resultant dramatic decrease in varicella incidence and a predicted future decrease in the incidence of zoster. The pathogenesis and immune responses to varicella zoster virus (VZV) as well as the safety and effectiveness of VZV vaccines are reviewed. The lack of sterilizing immunity provided by VZV vaccines has not prevented them from being safe and effective. Virological and pathological information concerning parallels and differences between VZV and herpes simplex virus (HSV) are highlighted. Although VZV and HSV are distinct pathogens, they appear to have similarities in target organs and immunity that provide an expectation of a high likelihood for the success of vaccination against HSV, and predicted to be similar to that of VZV.