Canadian Pain Society Study Day participants. Safety and effectiveness of the herpes zoster vaccine to prevent postherpetic neuralgia: 2014 Update and consensus statement from the Canadian Pain Society

Pharmacological and non-pharmacological strategies for preventing postherpetic neuralgia: a systematic review and network meta-analysis

Background

Postherpetic neuralgia (PHN) is a refractory complication of herpes zoster (HZ). To prevent PHN, various strategies have been aggressively adopted. However, the efficacy of these strategies remains controversial. Therefore, we aimed to estimate the relative efficacy of various strategies used in clinical practice for preventing PHN using a network meta-analysis (NMA).

Methods

We performed a systematic and comprehensive search to identify all randomized controlled trials. The primary outcome was the incidence of PHN at 3 months after acute HZ. We performed both frequentist and Bayesian NMA and used the surface under the cumulative ranking curve (SUCRA) values to rank the interventions evaluated.

Results

In total, 39 studies were included in the systematic review and NMA. According to the SUCRA value, the incidence of PHN was lower in the order of continuous epidural block with local anesthetics and steroids (EPI-LSE), antiviral agents with subcutaneous injection of local anesthetics and steroids (AV + sLS), antiviral agents with intracutaenous injection of local anesthetics and steroids (AV + iLS) at 3 months after acute HZ. EPI-LSE, AV + sLS and AV + iLS were also effective in preventing PHN at 1 month after acute HZ. And paravertebral block combined with antiviral and antiepileptic agents was effective in preventing PHN at 1, 3, and 6 months.

Conclusions

The continuous epidural block with local anesthetics and steroid, antiviral agents with intracutaneous or subcutaneous injection of local anesthetics and a steroid, and paravertebral block combined with antiviral and antiepileptic agents are effective in preventing PHN.

Public Health Impact and Cost-Effectiveness of Non-live Adjuvanted Recombinant Zoster Vaccine in Canadian Adults

OBJECTIVES

In Canada, incidences of herpes zoster (HZ) and postherpetic neuralgia (PHN) are increasing, posing a significant burden on the healthcare system. This study aimed to determine the public health impact and cost effectiveness of an adjuvanted recombinant zoster vaccine (RZV) compared to no vaccination and to the live attenuated vaccine (ZVL) in Canadians aged 60 years and older.

METHODS

A multi-cohort Markov model has been adapted to the Canadian context using recent demographic and epidemiologic data. Simulations consisted of age-cohorts annually transitioning between health states. Health outcomes and costs were discounted at 1.5% per year. The perspective of the Canadian healthcare payer was adopted. A coverage of 80% for the first RZV and ZVL dose and a compliance of 75% for the second RZV dose were assumed.

RESULTS

RZV was estimated to be cost effective compared with no vaccination with an incremental cost-effectiveness ratio (ICER) of $28,360 (Canadian dollars) per quality-adjusted life-year (QALY) in persons aged ≥ 60 years, avoiding 554,504 HZ and 166,196 PHN cases. Compared with ZVL, RZV accrued more QALYs through the remaining lifetime and an increase in costs of approximately $50 million resulting in an average ICER of $2396. Results were robust under deterministic and probabilistic sensitivity analyses. HZ incidence rate and persistence of vaccine efficacy had the largest impact on cost effectiveness.

CONCLUSIONS

The cost-utility analysis suggested that RZV would be cost effective in the Canadian population compared with no vaccination and vaccination with ZVL at a willingness-to-pay threshold of $50,000.

Impact of Out-of-Pocket Cost on Herpes Zoster Vaccine Uptake: An Observational Study in a Medicare Managed Care Population

Herpes zoster (HZ) vaccination is approved for adults aged 50+ for the prevention of HZ, but it is underutilized. The objective of this study was to evaluate the association between out-of-pocket cost and HZ vaccine utilization. Adults aged 65 or older enrolled for at least 12 months in Medicare Advantage/Part D (MAPD) and Medicare Part D only (PDP) plans from 1 January 2007 to 30 June 2014 were selected. Abandonment was defined as a reversed claim for HZ vaccine with no other paid claim within 90 days. Out-of-pocket costs used were actual amounts recorded in the claim. Overall, the HZ vaccine abandonment rate was 7.3%. Mean out-of-pocket costs were higher for individuals who abandoned versus those who did not ($88 (±$55) versus $80 (± $49)). Logistic regression indicated individuals with out-of-pocket costs of $80⁻$90 were 21% more likely (OR = 1.21, 1.16⁻1.27 95% CI), and those with out-of-pocket costs >$90 were 90% more likely (OR = 1.90, 1.85⁻1.96 95% CI) to abandon than those with out-of-pocket costs <$80. The models also suggested that socioeconomic, racial, and ethnic disparities in vaccine abandonment existed. Different vaccine targeting efforts and pharmacy benefit design strategies may be needed to increase use, improve adherence, and minimize disparities.