Burden of herpes zoster: the direct and comorbidity costs of herpes zoster events in hospitalized patients over 50 years in France

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.

The value of herpes zoster prevention in people aging with HIV: A narrative review

OBJECTIVE

Review the evidence on the incidence and impact of herpes zoster among people living with HIV and the potential impact of recombinant zoster vaccine for people aging with HIV.

METHODS

Narrative review.

RESULTS

Although antiretroviral therapy has substantially reduced the risk of herpes zoster among people living with HIV, they remain at an increased risk compared with the general population. Among people aging with HIV, aging per se is now the main risk factor for herpes zoster. Beyond pain, herpes zoster is also associated with a risk of sight-threatening complications in case of trigeminal involvement, disseminated diseases and stroke. Post-herpetic neuralgia is also a potential threat to the quality of life of people aging with HIV. The recombinant zoster vaccine has demonstrated high and sustained efficacy in the prevention of herpes zoster, post-herpetic neuralgia, and other herpes zoster complications in the general population. Immunogenicity data among people living with HIV with high CD4+ T-cell count and controlled viral load are comparable to those among the general population. Real-life effectiveness data indicate high vaccine efficacy among immunocompromised patients other than people living with HIV. High vaccine price, vaccine hesitancy, and limited disease and vaccine awareness represent potential hurdles for high vaccine uptake among people aging with HIV in Europe.

CONCLUSIONS

Herpes zoster, and its complications, is a vaccine-preventable disease of aging people. Given its impact on quality of life, herpes zoster prevention using recombinant zoster vaccine is a safe strategy to be considered in every person aging with HIV.

Validation of algorithms using International Classification of Diseases for the identification of herpes zoster episodes requiring hospitalization in Quebec, Canada

OBJECTIVE

We determined secular changes in the incidence of hospitalizations due to herpes zoster (HZh) and assessed the validity of HZ International Classification of Diseases (ICD) code algorithms for identifying HZh in a region of Quebec, Canada.

METHODS

We performed a validation study as part of a retrospective cohort study of adult HZ patients hospitalized at Centre Hospitalier Universitaire de Sherbrooke during 2000-2017. Cases were identified using ICD codes from an inpatient administrative database. HZ cases identified by ICD-9 (053.xx) and ICD-10 (B02.x) codes were chart-confirmed, and performance characteristics of ICD code algorithms were calculated (positive predictive value [PPV] and sensitivity).

RESULTS

Overall, 1314 hospitalizations with HZ diagnosis (HZh) with or without complications were identified during 2000-2017. Among the hospitalizations, 526 (44.4%) were due to active HZ disease or a complication related to a recent or previous HZ episode. These hospitalizations were due to active disease at the time of admission (340/526, 64.6%), HZ that developed during hospitalization (120/526, 22.8%), or a complication directly related to a recent or previous HZ episode (66/526, 12.6%). PPV was significantly higher when HZ was the primary diagnosis (276/310, 89%, 95% confidence interval [CI]: 85-92%) than when HZ was a secondary diagnosis (254/928, 27%, 95% CI: 25-30%) (p < 0.0001), and the PPV of a first secondary diagnosis (84/140, 60.0%, 95% CI: 51.3-68.2%) was higher than that of other secondary diagnoses (203/794, 25.6%, 95% CI: 22.6-28.8%) (p < 0.0001). An algorithm combining ICD codes and antiviral usage demonstrated the best sensitivity (86.3%, 95% CI: 83.1-89.1%) and PPV to identify HZh (100%, 95% CI: 99.2-100%). Poisson regression revealed no significant changes in HZh over time (incidence rate ratio: 0.98, 95% CI: 0.92-1.04%; p = 0.5).

CONCLUSION

HZh incidence was stable over time. Prescription of antivirals might be a useful addition to ICD codes to identify HZh cases from administrative databases.

Situational assessment of adult vaccine preventable disease and the potential for immunization advocacy and policy in low- and middle-income countries

By 2050, the number of adults over 65 years of age will be double the under-5 population, and heavily concentrated in low- and middle-income countries. Population growth and increasing life expectancies call for effective healthy aging strategies inclusive of immunization to reduce the burden of vaccine-preventable diseases, improve quality of life, and mitigate antimicrobial resistance. Based on a review of available literature on the pneumococcal disease, influenza, and herpes zoster epidemiology and economic burden, and the health systems and policy barriers for adult immunization, we identified evidence gaps and considerations for prioritizing adult immunization. The body of evidence for adult immunization and the health and economic burden of adult disease is heavily concentrated in high-income countries. The few countries reporting adult immunization policies generally focus on high-risk groups. Despite robust child immunization programs in most countries, adult immunization programs and policies lag far behind and there is a general lack of appropriate delivery platforms. Global adult disease burden and economic costs are substantial but evidence from low- and middle-income countries is limited. There is a need for a strengthened evidence base and political commitment to drive a comprehensive, global technical consensus on adult immunization.

Cross-sectional study on hospitalizations related to herpes zoster in an Italian region, 2008-2016

INTRODUCTION

To assess the burden of herpes zoster (HZ) by analyzing HZ-related hospital admissions.

METHODS

We conducted a population-based descriptive cross-sectional study on all hospitalizations for HZ among the resident population admitted to all public and accredited private hospitals in the Veneto Region (north-east Italy) during the years 2008-2016. HZ hospitalizations were identified from the International Classification of Diseases codes in the hospital discharge records.

RESULTS

During the period considered, we identified 3566 HZ-associated admissions, 194 (5.4%) of which were readmissions within 30 days. A complicated HZ diagnosis was mentioned for 44.4% of the patients admitted once and for 65.9% of those admitted twice. In the sample as a whole, 27.0% of patients had at least one comorbidity. Overall, our analysis revealed a gradual increase in hospitalizations with age for both genders, reaching a hospitalization rate for the population over 80 years old of 51.2 × 100,000 for males and 52.8 × 100,000 for females. The average hospitalization rate for HZ-related conditions during the years 2008-2016 was 7.7 per 100,000 population. Postherpetic neuralgia was diagnosed in 8.2% of hospitalizations, with no difference between the genders. The estimated overall cost of HZ-related conditions was approximately €2.7 million a year.

CONCLUSIONS

This study suggests that the burden of HZ and its impact on quality of life are of critical relevance to public health decision-making.

Herpes zoster in hospitalized adults: Practice gaps, new evidence, and remaining questions

Herpes zoster can present many uncertainties for consulting dermatologists. We review the current guidelines and recent literature on important issues that arise in the care of hospitalized patients with herpes zoster, including infection control isolation practices, treatment courses for zoster and acute zoster-associated pain, and indications for long-term prophylaxis. We present the findings of an inpatient zoster management practices survey of the membership of the Society of Dermatology Hospitalists, an expert resource group of the American Academy of Dermatology, and discuss directions for future investigation and potential opportunities for management improvements in light of these collective data.

Impact of Underlying Conditions on Zoster-Related Pain and on Quality of Life Following Zoster

BACKGROUND

Chronic conditions have been investigated as risk factors for developing zoster, but in patients suffering from zoster, the impact of underlying conditions in zoster-related pain and quality of life (QOL) remains unclear.

METHODS

We performed a post hoc analysis of a prospective cohort study in immunocompetent zoster patients aged 50 years or older, conducted by general practitioners in Italy between 2009 and 2010. Zoster symptoms, pain intensity and characteristics, and physical and mental health scores were assessed at baseline (zoster diagnosis) and at 1, 3, and 6 months of follow-up.

RESULTS

Among 413 patients enrolled in the study, 73% (303/413) suffered from underlying conditions of which 69% (209/303) were aged 65 or older. Cardiovascular diseases (75%), diabetes (24%), and respiratory diseases (17%) were most frequent. One to three months after onset, zoster patients with underlying conditions experienced more intense zoster-related pain than those without. QOL scores were significantly lower in patients with underlying conditions, and age-adjusted difference in QOL scores between the groups increased over time, demonstrating a slower recovery for patients with underlying conditions.

CONCLUSIONS

In addition to age, the main risk factor of zoster occurrence and severity, the presence of underlying conditions results in more painful and impactful zoster episodes, creating a significant burden for these patients.

Receipt of thyroid hormone deficiency treatment and risk of herpes zoster

OBJECTIVE

Thyroid hormone (TH) has been suggested to control herpes virus gene expression and replication in neurons via epigenetics through its nuclear receptors. It has previously been shown that patients with hypothyroidism are predisposed to herpes zoster (HZ), suggesting that the TH deficiency may be a risk factor for varicella zoster virus (VZV) reactivation. The aim of this study was to test the hypothesis that TH treatment will ameliorate the complication of HZ.

METHODS

This study investigated the hypothesis by enquiring into a comprehensive medical database at Kaiser Permanente Southern California (KPSC) to verify whether patients taking TH medication experience a reduction in HZ occurrence.

RESULTS

It was shown by Kaplan-Meier analysis that hypothyroidism patients taking TH medicines had a lower risk of HZ. The fully adjusted analysis indicated that patients receiving medication for the treatment of TH deficiency exhibited a reduced risk of HZ (hazard ratio 0.60, 95% confidence interval 0.51-0.71). This lower risk of HZ was significant in all age groups except the 18-39 years cohort. In addition, female patients taking TH treatment exhibited a lower risk than their male counterparts.

CONCLUSIONS

Together these findings support the hypothesis that a constant level of TH will provide a degree of protection from contracting HZ. More studies are underway to evaluate the laboratory data for an analysis of hormonal effects on individuals.

Incidence of varicella zoster virus infections of the central nervous system in the elderly: a large tertiary hospital-based series (2007-2014)

The aim of the study was to describe the clinical and epidemiological characteristics of the central nervous system (CNS) infection by varicella zoster virus (VZV) in patients older than 65 years in a tertiary community hospital. We retrospectively analysed the results of cerebrospinal fluid (CSF) testing in patients older than 65 years between 2007 and 2014 with clinically suspected VZV infection with CNS involvement. Patients whose CSF samples were positive for VZV DNA were included, as were those with negative results who simultaneously presented herpes zoster and CSF or magnetic resonance imaging findings suggestive of CNS infection, and in whom other possible aetiologies had been ruled out. The study included 280 patients. The disease was considered to be caused by a VZV infection in 32 patients (11.4%), of which 23 cases were virologically confirmed (detection of VZV DNA in CSF). The most frequent diagnosis of the patients with VZV CNS infection was encephalitis (83.3%), followed by meningitis (13.3%) and cerebellitis (3.3%). The mean annual incidence of VZV CNS infection was 3.0 cases per 100,000 inhabitants. VZV was the most common cause of encephalitis and viral meningitis, ahead of herpes simplex virus (n = 9). At the time of discharge, 12 (40%) patients showed neurological sequelae. Five patients (20%) died during hospitalization, all with encephalitis. Patients with a fatal outcome had significantly higher median age and longer delay before initiating acyclovir. In conclusion, VZV was the first cause of encephalitis in our elderly population. Despite acyclovir treatment, there was a high rate of case fatality and sequelae at discharge.

Cost of shingles: population based burden of disease analysis of herpes zoster and postherpetic neuralgia

Background

Around 30% of the population will experience herpes zoster (HZ), 10% of whom develop postherpetic neuralgia (PHN). Together, these illnesses produce a significant economic burden to the healthcare system.

Methods

Administrative healthcare data collected over the period of April 1^st 1997 to March 31^st 2014 were analyzed to determine the healthcare system burden of HZ using direct medical costs. Episodes of HZ were identified using international classification of disease (ICD) codes. Trends in age-adjusted (AA) HZ-rates were analyzed by piecewise-regression. Total annual and per-episode costs were determined for drug treatment, medical care, and hospitalizations within each year.

Results

The incidence of HZ increased by 49.5% from 1997/98 to 2013/14. Piecewise-regression of AA-rates revealed a steady AA-rate of 4.7 episodes/1000 person-years (PY) from 1997/98 to a breakpoint in 2008/09, after which rates began to increase reaching 5.7 episodes/1000 PY in 2013/14.

Drug costs rose significantly (p <0.03) from $89.77/episode (95% CI: $82.96, $96.59) to $127.34/episode (95% CI: $117.24, $137.44). Medical costs increased (p <0.0001) from $57.98/episode (95% CI; $55.26, $60.70) to $78.84/episode (95% CI; $74.08, $83.61). Hospitalization rates declined from 3.10% in 1997/98 to 1.36% in 2011/12, resulting in cost dropping from $397/episode (95% CI; $284, $511) to $195/episode (95% CI; $129, $260).

Total annual costs of HZ and PHN were $1,997,183 in 2011/12, 4.7% lower than the 1997/98 costs of $2,095,633.

Conclusion

A significant increase in annual number of HZ cases was observed, driven largely by demographic factors. A 21% increase in the AA-incidence reveals changes in HZ rates beyond those expected by population shifts.

The large increase in incidence of HZ, with rising per episode medical and prescription costs were offset by dramatic drops in hospitalization rates, the net effect of which has been to hold the total costs relatively constant. However, the decrease in hospitalization rates slowed over the last half of the study, settling at 1.3% in the last 4 study years. The likely future of HZ burden is one of rising costs, primarily driven by the demographic shifts of an increasing and aging population.

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.

Hospital-based herpes zoster diagnoses in Denmark: rate, patient characteristics, and all-cause mortality

Background

Herpes zoster (HZ) may result in severe complications requiring hospital treatment, particularly in patients with comorbidity. Nevertheless, data on HZ from nationwide population-based hospital registries are sparse.

Methods

We conducted a cohort study describing first-time hospital-based (inpatient, outpatient, and emergency room) HZ diagnoses in the Danish National Patient Registry, 1994–2012. We computed the diagnosis rate; prevalence of demographic characteristics, comorbidities, and complications; length of hospital stay; and standardized mortality ratios (SMRs) using the Danish population as reference. We classified comorbidity using the Charlson Comorbidity Index (CCI) scoring system and categorized patients in groups of no (score 0), moderate (score 1), severe (score 2), and very severe comorbidity (score ≥3). In addition, we computed the prevalence of certain conditions associated with immune dysregulation (stem cell or bone marrow transplantation, solid organ transplantation, HIV infection, primary immunodeficiency, any cancer, and autoimmune diseases).

Results

The diagnosis rate increased almost exponentially from 6 to 91.9 per 100,000 person-years between age 50 and ≥90 years. The age-standardized rate was stable throughout the study period. The median length of hospital stay was 4 days (interquartile range: 1–8 days) for inpatients with HZ as the main reason for admission. According to the CCI, 44.3 % of patients had no comorbidity, 17.3 % moderate comorbidity, 17.4 % severe comorbidity, and 21.0 % very severe comorbidity. Comorbidities involving immune dysregulation, such as malignant (21 %) and autoimmune diseases (17 %), were particularly prevalent. Thirty percent had neurological, ophthalmic, or other complications. HZ was associated with increased all-cause mortality overall (SMR 1.8, 95 % CI: 1.7–1.8), but not in analyses restricted to patients without comorbidity (SMR 1.0, 95 % CI: 0.9–1.0).

Conclusions

This study provides estimates of the epidemiology of hospital-based (severe) HZ. The diagnosis rate increased substantially with age. Complications and comorbidities were prevalent, likely resulting in increased mortality.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1369-6) contains supplementary material, which is available to authorized users.