[Burden of herpes zoster and postherpetic neuralgia: Incidence, proportion, and associated costs in the French population aged 50 or over]

Cost of illness of the vaccine-preventable diseases influenza, herpes zoster and pneumococcal disease in France

BACKGROUND

The incidence of certain vaccine-preventative diseases, such as influenza, herpes zoster and pneumococcal infection, continues to be high despite the availability of vaccines, resulting in a substantial health and economic burden on society, particularly among older adults aged ≥65 years.

METHODS

A cost calculator was developed to assess the cost of illness of influenza, herpes zoster and pneumococcal disease in France. Direct medical costs related to diagnosis and treatment in the older adult population in both inpatient and outpatient settings were modelled over a 1-year time horizon. Scenario analyses were conducted to determine the impact of hospitalizations on the results by considering only influenza-attributed diagnoses.

RESULTS

In France, influenza has the highest incidence, followed by herpes zoster and pneumococcal disease. Similarly, influenza poses the greatest cost burden among all older adults, while pneumococcal disease poses the greatest cost burden among those aged 65-74 years. When considering only influenza-attributed diagnoses, the number of inpatient visits and associated costs was reduced by 63% in the overall older adult population. In the low-incidence season, the number of inpatient visits and associated costs were reduced by 69%, while in the high-incidence season, the number of inpatient visits and associated costs increased by 63%.

CONCLUSION

Influenza remains a leading vaccine-preventable disease among older adults in France, resulting in a substantial economic burden that could be prevented by increasing vaccine uptake.

Incidence of complications of herpes zoster in individuals on immunosuppressive therapy: A register-based population study

OBJECTIVES

Herpes zoster (HZ) exposes to alterations of the quality-of-life. HZ is more frequent in immunocompromised individuals, but whether immunosuppression is associated with a higher rate of complications is not well documented. We aimed to assess association between drug-induced immunosuppression and HZ complications.

METHODS

Data from a sample of the French healthcare claims from 01/01/2006 to 12/31/2018 were analyzed. Complicated zoster (CZ) was defined as a hospitalization with a code for HZ or the first-time dispensation of high-dose valacyclovir and specific neuralgia analgesics. Drug-induced immunosuppression was identified through medication dispensation. Risk ratios were calculated to compare incidences in exposed individuals (EI) and non-exposed to immunosuppressive therapy (NEI).

RESULTS

We identified 227 and 2838 CZ, accounting for an incidence of 178 per 100,000 person-year (95%CI[154.9-201.1]) and 51.7 per 100,000 person-year (95%CI[49.8-53.6]), in EI and NEI, respectively (risk ratio: 3.44 (95%CI[3.01-3.94]). Mean age was 66 years in both groups. CZ occurred after a median of 11.7 months (IQR[5.3-49.9]) of immunosuppressive therapy. Post-herpetic neuralgia (PHN) lasted at least 3 months in 32.6% and 22.5% of cases in EI and NEI, respectively (p=.01).

CONCLUSIONS

Drug-induced immunosuppression increases the risk of CZ and exposes to longer-lasting PHN. Figures provided in this study could help guide prophylaxis of HZ.

A systematic literature review of herpes zoster incidence worldwide

We conducted a systematic review to characterize the incidence rate of herpes zoster (HZ) in the general population, specifically in individuals ≥50 years of age. A total of 69 publications were included in the review. We found a cumulative incidence of HZ ranging from 2.9–19.5 cases per 1,000 population and an incidence rate of HZ ranging from 5.23–10.9 cases per 1,000 person-years. The cumulative incidence (3.22–11.2 versus 2.44–8.0 cases per 1,000 population) and incidence rates (6.05–12.8 versus 4.30–8.5 cases per 1,000 person-years) were higher in females than males. Studies revealed a trend of increasing incidence of HZ with increasing age and over time. Variations in incidence estimates can be attributed to the various study designs, case ascertainments, age distributions of the population and year of the study. HZ is associated with a substantial disease burden and is expected to increase due to population aging.

Effectiveness of acupuncture therapy for postherpetic neuralgia: an umbrella review protocol

INTRODUCTION

Several systematic reviews and meta-analysis indicate that acupuncture and related therapies may be a valuable adjunctive technique to pharmacological interventions for pain management of postherpetic neuralgia (PHN). However, the robustness of the results of these studies has not been evaluated. The aim of this proposed umbrella review is to provide more reliable evidence of the effectiveness of acupuncture therapy for PHN based on medical references for healthcare decision makers.

METHODS AND ANALYSIS

PubMed, EMBASE, The Cochrane Library, Web of Science, Chinese BioMedical Literature Database, VIP Database for Chinese Technical Periodicals, China National Knowledge Infrastructure and Wan fang Database will be used to retrieve reviews. The time of publication will be limited from inception to March 2021. Two reviewers will screen all retrieved articles independently to identify their eligibility and extract the data. The quality will be assessed independently by two trained reviewers using Assessment of Multiple Systematic Reviews-2 for methodological quality, Risk of Bias in Systematic Review for level of bias, Preferred Reporting Items for Systematic Reviews and Meta-Analysis for reporting quality and Grading of Recommendations Assessment, Development and Evaluation for the quality of evidence. Any disagreements will be settled by discussion or the involvement of a third reviewer.

ETHICS AND DISSEMINATION

The protocol of this review does not require ethical approval because the research will be based on publicly available data. The findings will be disseminated through publication in peer-reviewed international journals or presentation in academic conference.

PROSPERO REGISTRATION NUMBER

CRD42020173341.

REPORTING CHECKLIST

PRISMA-P, 2015.

Comparison of therapeutic effects of continuous epidural nerve block combined with drugs on postherpetic neuralgia

PURPOSE

To compare the therapeutic effects of continuous epidural block combined with drugs and oral drugs alone on postherpetic neuralgia (PHN).

METHODS

Ninety-six PHN patients meeting the standard were selected and divided into group A and group B. Patients in group A had epidural block combined with oral administration of gabapentin and oxycodone-acetaminophen, and patients in group B received oral gabapentin and oxycodone-acetaminophen. Visual analogue scale (VAS) and Wisconsin brief pain inventory scores were used to evaluate the patients in group A and group B for 6 times (before treatment, 1 d, 3 d, 7 d, 15 d and 30 d after treatment) respectively, and the complications and adverse reactions of the two treatment methods, as well as the number of cases requiring remedial measures were observed.

RESULTS

There were significant differences in VAS and Wisconsin brief pain inventory scores at 1 d, 3 d, 7 d, 15 d and 30 d after treatment between the two groups (p < 0.05). Moreover, the scores before and after treatment decreased with the time of treatment, and there was a significant difference between the two groups at different time points (p < 0.05). No significant adverse reactions were observed in group A except for 1 patient with catheter detachment. Compared with group A, the adverse reactions of group B were more varied and obvious.

CONCLUSION

Both treatments have certain effects on PHN, but epidural block combined with drug therapy is more effective, especially for patients with severe pain, early use can quickly relieve pain.

Incidence of herpes zoster amongst adults varies by severity of immunosuppression

OBJECTIVES

We examined the incidence of herpes zoster in immunocompromised adults (≥18 years) with different severities of immunosuppression and assessed the prevalence of complications and of various kinds of healthcare resource utilisation.

METHODS

German claims data from more than ten million adults were used to calculate annual incidence rates of herpes zoster for the years 2006-2012 and to analyse the prevalence of complications, physician visits, hospitalisations, and antiviral and analgesic treatments using a cohort design. The analyses were stratified by age, sex, and severity of immunosuppression, defined by immunocompromising conditions and drug therapies.

RESULTS

The incidence rate per 1000 person-years of herpes zoster was almost twice as high in immunocompromised patients (11.5 (95% confidence interval (CI): 11.4-11.6)) compared to immunocompetent subjects (5.9 (95% CI: 5.8-5.9)). The incidence rate was higher in highly immunocompromised patients (13.4 (95% CI: 13.2-13.6)) than in patients with a low severity of immunosuppression (10.0 (95% CI: 9.8-10.1)). These differences were observed for both sexes and in all age groups. Complications, outpatient physician visits, hospitalisations, and analgesic treatments occurred more frequently in immunocompromised patients as well.

CONCLUSIONS

Our results show that immunocompromised individuals are affected by the disease in particular and that the burden of herpes zoster is highest in severely immunocompromised patients.

COST-EFFECTIVENESS ANALYSIS OF HERPES ZOSTER VACCINATION IN ITALIAN ELDERLY PERSONS

Objectives:Herpes zoster (HZ) is characterized by a painful skin rash. Its main complication is postherpetic neuralgia (PHN), pain persisting or occurring after the rash onset. HZ treatment aims to reduce acute pain, impede the onset complications, and disease progression. The aim of this study was to assess the cost-effectiveness of HZ vaccination compared with no vaccination strategy, within the Italian context.

Methods:The natural history of HZ and PHN was mapped through a Markov model with lifetime horizon. A population of patients aged between 60 and 79 years was hypothesized. Third party payer (Italian National Health Service, I-NHS) and societal perspectives were adopted. Data were derived from literature.

Results and Conclusions:The incremental cost-effectiveness ratio of the vaccination equaled EUR 11,943 per quality-adjusted life-year (QALY) under the I-NHS perspective and EUR 11,248 per QALY under the societal perspective. Considering a cost-effectiveness threshold of EUR 30,000/QALY, the multi-way sensitivity analysis showed that vaccination is cost-effective regardless of the perspective adopted, in 99 percent of simulations.

Cost-effectiveness of a herpes zoster vaccination program among the French elderly people

A vaccine against herpes zoster (HZ) and its complications has already proven safe and effective against infection and pain and against the related deterioration of quality of life in the elderly. In order to inform the vaccination decision-making process regarding inclusion of this vaccine in the French immunization schedule, we assessed the cost-effectiveness of several vaccination scenarios, compared to no vaccination. We chose to use a previously published Markov model. Starting vaccination in elderly individuals aged 65, 70 and 75 y old appears more cost-effective than vaccination for those aged 60 y old, with a cost-effectiveness ratio between 30,000 and 35,000 euros per quality-adjusted-life year (QALY) gained for the first 3 age groups versus 54,500 €; for the latter group. These results largely contributed to the recommendation to include the HZ vaccination in the French immunization schedule for people aged between 65 and 74 y old in France.

The use of Zostavax in Spain: the economic case for vaccination of individuals aged 50 years and older

Background Population aging brings up a number of health issues, one of which is an increased incidence of herpes zoster (HZ) and its complication, post-herpetic neuralgia (PHN). Zostavax vaccine has recently become available to prevent HZ and PHN. This study evaluates the cost-effectiveness of vaccination against HZ in Spain considering a vaccination of the population aged 50 years and older and comparing this to the current situation where no vaccination is being administered. Methods An existing, validated, and published economic model was adapted to Spain using relevant local input parameters and costs from 2013. Results Vaccinating 30% of the Spanish population aged 50 years and older resulted in €16,577/QALY gained, €2025/HZ case avoided, and €5594/PHN case avoided under the third-party payer perspective. From a societal perspective, the ICERs increased by 6%, due to the higher price of the vaccine. The number needed to vaccinate to prevent one case was 20 for HZ, and 63 for PHN3. Sensitivity analyses showed that the model was most sensitive to the HZ and PHN epidemiological data, the health state utilities values, and vaccine price used. Conclusion Considering an acceptable range of cost-effectiveness of €30,000-€50,000 per QALY gained, vaccination of the 50+ population in Spain against HZ with a new vaccine, Zostavax, is cost-effective and makes good use of the valuable healthcare budget.

Epidemiology of herpes zoster among adults aged 50 and above in Guangdong, China

Herpes zoster (HZ) exists widely in China and most cases occur among old people, but no epidemiology information of HZ was available. We aimed to investigate the epidemiology characteristics of HZ among adults aged 50 and over in Guangdong, China. A total of 34 counties/districts were randomly selected in Guangdong, and 7149 residents aged 50 and over were investigated by local CDC professionals using accidental sampling method. There were 247 respondents having had HZ before; the lifetime prevalence of HZ among people aged 50 and above in study area was 3.46%. The prevalence in females was higher than that in males. Pearl River Delta had the highest prevalence (5.29%), while Northern Guangdong had the lowest (1.87%). The annual incidence in the year 2013, 2012 and 2011 was 5.8, 3.4 and 4.1 per 1000 person-years, respectively. Detailed investigation of HZ cases showed that all cases meted the definition of HZ and had at least 1 typical symptom. 40% cases had suffered post-herpetic neuralgia. 75.9% cases had sought aid from hospital and 9.1% of them had been hospitalized. People who sought aid from hospital had more serious level of neuralgia. The epidemiology features of HZ in Guangdong were consistent with the current findings in other countries. The results of this study can provide baseline epidemiology information of HZ for further studies.

Immunogenicity and Safety of a Live Attenuated Zoster Vaccine (ZOSTAVAX™) in Korean Adults

A live attenuated zoster vaccine (ZOSTAVAX™, Merck & Co., Inc.) was approved by the Korea Ministry of Food and Drug Safety in 2009. However, the immunogenicity and safety of the vaccine has not been assessed in Korean population. This is multi-center, open-label, single-arm study performed with 180 healthy Korean adults ≥ 50 yr of age. The geometric mean titer (GMT) and geometric mean fold rise (GMFR) of varicella zoster virus (VZV) antibodies were measured by glycoprotein enzyme-linked immunosorbent assay (gpELISA) at 4 weeks post-vaccination. Subjects were followed for exposure to varicella or herpes zoster (HZ), the development of any varicella/varicella-like or HZ/HZ-like rashes, and any other clinical adverse experiences (AEs) for 42 days post-vaccination. For the 166 subjects included in the per-protocol population, the GMT at Day 1 was 66.9. At 4 weeks post-vaccination, the GMT for this population was 185.4, with a GMFR of 2.8 (95% CI, 2.5-3.1). Of the 180 subjects vaccinated, 62.8% experienced ≥ 1 AE, with 53.3% of subjects reporting injection-site AEs. The most frequently reported injection-site AEs were erythema (45.0%) with the majority being mild in intensity. Overall, 44 (24.4%) subjects experienced ≥ 1 systemic AE, 10 (5.5%) subjects experienced a systemic vaccine-related AE, and 3 (1.7%) subjects experienced ≥ 1 serious AE not related to vaccine. No subjects reported a VZV-like rash. There was no subject of death and no subject discontinued due to an adverse event. A single dose of zoster vaccine induced VZV-specific gpELISA antibody response and was generally well-tolerated in healthy Korean adults ≥50 yr of age (registry at www.clinicaltrial.gov No. NCT01556451).

Evaluation of the economic burden of Herpes Zoster (HZ) infection

The main objective of this systematic review was to evaluate the economic burden of Herpes Zoster (HZ) infection.   The review was conducted in accordance with the standards of the "Preferred Reporting Items for Systematic Reviews and Meta-Analyses" guidelines. The following databases were accessed: ISI/Web of Knowledge (WoS), MEDLINE/PubMed, Scopus, ProQuest, the Cochrane Library and EconLit. Specific literature on health economics was also manually inspected. Thirty-three studies were included. The quality of the studies assessed in accordance with the Consolidated Health Economic Evaluation Reporting Standards checklist was good. All studies evaluated direct costs, apart from one which dealt only with indirect costs. Indirect costs were evaluated by 12 studies. The economic burden of HZ has increased over time. HZ management and drug prescriptions generate the highest direct costs. While increasing age, co-morbidities and drug treatment were found to predict higher direct costs, being employed was correlated with higher indirect costs, and thus with the onset age of the disease. Despite some differences among the selected studies, particularly with regard to indirect costs, all concur that HZ is a widespread disease which has a heavy social and economic burden.

Burden of herpes zoster and post-herpetic neuralgia in Sweden

Background

The societal economic burden of herpes zoster in Sweden is not well described today. This study is a top-down analysis of Swedish registers with the objective to describe the burden of herpes zoster and post-herpetic neuralgia in Sweden during 2011.

Methods

Data for inpatient care; outpatient primary and specialized cares; the prescriptions of drugs, sick leave and the number or diagnostic tests were collected from Swedish national databases. The incidence of the disease was estimated based on the number of prescriptions of antiviral drugs.

Results

The incidence of herpes zoster was estimated to 315 and 577 cases per 100,000 people for patients at all ages and > = 50 years, respectively. Almost 30,000 patients at all ages were diagnosed with herpes zoster and the societal cost to treat these patients, including the cost to treat those patients who later developed post-herpetic neuralgia, added up to nearly 227 MSEK (31.6 M€) which corresponds to 7,600 SEK (€870) per patient. The main contributors to the total cost for the treatment of HZ patients were primary care (43 %); sick leave (28 %); hospitalization (10 %) and specialist care (7 %). Medication was a relatively small contributor with 8.5 MSEK (4 %; 1.0 M€) to the overall costs for patients at all ages. The corresponding total cost including only patients 50 years and older was 168 MSEK (19.2 M€) or 8,200 SEK (€939) per patient.

Conclusions

The current study demonstrates that the burden of herpes zoster is significant in Sweden. The society, the health care payers and the patients potentially have a lot to gain by introducing a vaccination program to patients 50 years and older and as a consequence reduce the economic and clinical burden of herpes zoster and post-herpetic neuralgia.

The humanistic, economic and societal burden of herpes zoster in Europe: a critical review

BACKGROUND

Herpes zoster (HZ) or "shingles" is common in persons aged 50 years or over. HZ is characterised by a painful dermatological rash which typically resolves in approximately one month. Persistent pain for months or years after rash onset, however, is a common complication of HZ; referred to as post-herpetic neuralgia (PHN). Both HZ and PHN have a significant impact on patients' lives, with considerable implications for healthcare systems and wider society. The aim of the present review is to provide comprehensive documentation and critical appraisal of published data concerning the humanistic, economic and societal burden of HZ in Europe.

METHODS

Systematic literature searches were conducted in Medline, EMBASE, PsycINFO, EconLit, HEED and CRD databases. Searches were conducted in July 2014 and restricted to articles published in the past 20 years. Articles were selected for full review by two independent researchers in accordance with predefined eligibility criteria.

RESULTS

From a review of 1619 abstracts, 53 eligible articles, were identified which reported data concerning healthcare resource use (n = 38), direct costs (n = 20), indirect costs (n = 16), total costs (n = 10) and impact on health-related quality of life (HRQoL) (n = 21). Findings highlight that PHN is associated with greater impairments in HRQoL and higher costs of management than HZ. For both HZ and PHN, pain severity is a significant predictor of impact on individuals, healthcare systems and society. While the incidence of HZ and PHN increase with age, age does not appear to be a key driver of overall costs for HZ and PHN. Specifically, while direct costs (e.g. GP, specialists, medications, hospitalisations) tend to be higher for older patients, indirect costs (e.g. work time missed) are higher for younger patients.

CONCLUSIONS

Available evidence highlights that HZ and PHN result in significant humanistic and economic burden for patients, healthcare systems and wider societies. A tendency to focus upon healthcare resource use and the direct costs of management at the expense of other impacts (e.g. informal caregivers and formal social care) may result in an underestimation of the true burden of HZ and PHN.

Burden of herpes zoster-associated chronic pain in Italian patients aged 50 years and over (2009-2010): a GP-based prospective cohort study

Background

Post-herpetic neuralgia (PHN) is the most common complication in herpes zoster (HZ) patients.

Methods

We performed a longitudinal, prospective study in 108 general practices throughout Italy to assess how many immunocompetent patients aged ≥50 years with newly diagnosed HZ develop HZ-associated pain, its duration and management over 6-months. HZ-associated pain was assessed by a direct question to the patient and by self-assessment of the worst pain felt in the previous two weeks on a visual analogue scale (VAS), a score ≥3 was taken as pain. PHN was defined as pain reported during the study period persisting for ≥3 months. Quality of life (QoL) was measured using the SF-12 questionnaire.

Results

At enrolment, 370 of the 413 patients (89.6%) reported HZ-associated pain which was still present in 20.6% and 9.2% of patients after three and six months, respectively, despite many patients receiving recommended anti-viral therapy. The overall QoL scores were lower than those in healthy Italians of similar age; scores for patients with HZ-associated pain were lower. The presence of >50 vesicles and VAS score ≥3 at enrolment, and being male were significantly associated with PHN at three months.

Conclusions

These results suggest that HZ and PHN represent an important burden of disease in the elderly. There is a need for interventions that can prevent and reduce the burden of HZ to help improve the quality of life of the elderly. These data may be useful as baseline epidemiology data for the assessment of the impact of the VZV vaccine in Italy, after its implementation.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-014-0637-6) contains supplementary material, which is available to authorized users.

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.

Similar herpes zoster incidence across Europe: results from a systematic literature review

Background

Herpes zoster (HZ) is caused by reactivation of the varicella-zoster virus (VZV) and mainly affects individuals aged ≥50 years. The forthcoming European launch of a vaccine against HZ (Zostavax®) prompts the need for a better understanding of the epidemiology of HZ in Europe. Therefore the aim of this systematic review was to summarize the available data on HZ incidence in Europe and to describe age-specific incidence.

Methods

The Medline database of the National Library of Medicine was used to conduct a comprehensive literature search of population-based studies of HZ incidence published between 1960 and 2010 carried out in the 27 member countries of the European Union, Iceland, Norway and Switzerland. The identified articles were reviewed and scored according to a reading grid including various quality criteria, and HZ incidence data were extracted and presented by country.

Results

The search identified 21 studies, and revealed a similar annual HZ incidence throughout Europe, varying by country from 2.0 to 4.6/1 000 person-years with no clearly observed geographic trend. Despite the fact that age groups differed from one study to another, age-specific HZ incidence rates seemed to hold steady during the review period, at around 1/1 000 children <10 years, around 2/1 000 adults aged <40 years, and around 1–4/1 000 adults aged 40–50 years. They then increased rapidly after age 50 years to around 7–8/1 000, up to 10/1 000 after 80 years of age. Our review confirms that in Europe HZ incidence increases with age, and quite drastically after 50 years of age. In all of the 21 studies included in the present review, incidence rates were higher among women than men, and this difference increased with age. This review also highlights the need to identify standardized surveillance methods to improve the comparability of data within European Union Member States and to monitor the impact of VZV immunization on the epidemiology of HZ.

Conclusions

Available data in Europe have shortcomings which make an accurate assessment of HZ incidence and change over time impossible. However, data are indicative that HZ incidence is comparable, and increases with age in the same proportion across Europe.

Vaccination against herpes zoster and postherpetic neuralgia in France: a cost-effectiveness analysis

This study assesses the cost-effectiveness of vaccination against herpes zoster (HZ) and postherpetic neuralgia in France, using a published Markov model. The cost-effectiveness of vaccinating individuals aged from 65 years or between 70 and 79 years was evaluated over their lifetime, from a third-party payer perspective. French-specific data were combined with results from clinical studies and international quality-of-life-based (EuroQol five-dimension questionnaire) utilities from the literature. HZ vaccination was highly cost effective in both populations. Incremental cost-effective ratios were estimated between €9513 and 12,304 per quality-adjusted life year gained, corresponding to €2240-2651 per HZ case avoided and €3539-4395 per postherpetic neuralgia case avoided. In addition to epidemiological and clinical evidence, economic evidence also supports the implementation of HZ vaccination in France.

A systematic review of the cost effectiveness of herpes zoster vaccination

BACKGROUND

The varicella zoster virus (VZV) can cause two infections: chickenpox or herpes zoster (HZ). Whereas chickenpox infections are normally mild but common among children, HZ infections are common among elderly people and can give rise to post-herpetic neuralgia (PHN), a severe and painful complication.

OBJECTIVES

This review aimed to summarize the literature available on the cost effectiveness of HZ vaccination and to summarize key issues for decision makers to consider when deciding on the reimbursement of HZ vaccination.

METHODS

We conducted a literature search of the databases PubMed and EMBASE using EndNote X4 from Thomson Reuters. The following combinations of keywords were used: 'herpes zoster vaccine' AND 'cost(-)effectiveness' or AND 'economic evaluation', 'herpes zoster vaccination' AND 'cost(-)effectiveness' or AND 'economic evaluation', 'varicella zoster vaccine' AND 'cost(-)effectiveness' or AND 'economic evaluation', and 'varicella zoster vaccination' AND 'cost(-)effectiveness' or AND 'economic evaluation'.

RESULTS

A total of 11 studies were identified and included. Cost-effectiveness analyses of varicella zoster vaccination were excluded. The quality of the included studies ranged from 'moderate' to 'moderate to good' according to the British Medical Journal guidelines of Drummond and Jefferson and the Quality of Health Economic Studies (QHES) score of Ofman et al. Most studies evaluated the cost effectiveness of universal HZ vaccination in adults aged 50 years or 60 years and older. Data sources and model assumptions regarding epidemiology, utility estimates and costs varied between studies. All studies calculated costs per QALY, which allows comparing costs of interventions in different diseases. The costs per QALY gained and the incremental cost-effectiveness ratio (ICER) differed between studies depending on the age at vaccination, duration of vaccine efficacy, cost of vaccine course and economic perspective. All but one of the studies concluded that most vaccination scenarios are cost effective and the vaccination of specific subgroups such as the older age group is most cost effective.

CONCLUSIONS

Model input parameters such as age at vaccination, vaccine costs, HZ incidence, PHN length and duration of vaccine efficacy had a great impact on the estimated cost effectiveness of HZ vaccination. To compare the results of different cost-effectiveness studies of HZ vaccination, uniform methods should be used and the most important input parameters used for the different models should be critically assessed.

Predictive factors for postherpetic neuralgia using ordered logistic regression analysis

OBJECTIVES

To identify predictive factors for the occurrence of postherpetic neuralgia (PHN).

METHODS

The participants were 73 herpes zoster patients who had been treated at the pain clinic of our hospital between January 2008 and June 2010. Variables present at the initial visit were extracted from the clinical records for regression analysis of factors related to the occurrence of PHN. The following scores for response were used: 0=no PHN after 3 months; 1=PHN present after 3 months but absent after 6 months; and 2=PHN present after 6 months. Multivariate ordered logistic regression analysis was performed to identify the predictive factors for PHN.

RESULTS

Advanced age [odds ratio (OR)=2.740, confidence interval (CI)=1.110-6.761; P=0.0288] and deep pain (OR=4.244, CI=1.114-16.163; P=0.0341) at the initial visit to our outpatient pain clinic were found to be significant predictive factors for the occurrence of PHN. Diabetes mellitus (OR=3.075) and pain reduced by bathing (OR=3.389) also had high OR, although they were not significant.

DISCUSSION

Our study indicates that advanced age and deep pain at the initial visit are significant predictors for PHN. Our results are considered likely to contribute to the establishment of evidence-based medicine in the optimal treatment of PHN.