Valuing outcomes in health care: a comparison of willingness to pay and quality-adjusted life-years

Willingness to pay for a quality-adjusted life year: a systematic review with meta-regression

The use of a threshold for cost-utility studies is of major importance to health authorities for making the best allocation decisions for limited resources. Regarding the increasing number of studies worldwide that seek to establish a value for a quality-adjusted life year (QALY), it is necessary to review these studies to provide a global insight into the literature. A systematic review on willingness to pay (WTP) studies focusing on QALY was conducted in eight databases up to June 26, 2020. From a total of 9991 entries, 39 studies were selected, and 511 observations were extracted for the meta-analysis using the ordinary least squares method. The results showed a predicted mean empirical value of $52,619.39 (95% CI 49,952.59; 55,286.19) per QALY in US dollars for 2018. A 1% increase in income led to an increase of 0.6% in the WTP value, while a 1-year increase in respondent age led to a decrease of 3.3% in the WTP value. Sex, education level and employment status had significant effects on WTP. Compared to face-to-face interviews, surveys conducted by the internet or telephone were more likely to have a significantly higher value of WTP per QALY, while out-of-pocket payment tended to lower the value. The prediction made for the province of Quebec, Canada, provided a QALY value of approximately USD $98,450 (CAD $127,985), which is about 2.3 times its gross domestic product (GDP) per capita in 2018. This study is consistent with the extant literature and will be useful for countries that do not yet have a preference-based survey for the value of a QALY.

Willingness to pay vs lottery equivalent to value the impact of alcohol misuse on quality of life

OBJECTIVES

To estimate the impact of alcohol disorders using lottery equivalent (LE) and willingness to pay (WTP) methods and compute the WTP for a QALY (WTP-Q) derived from these values.

METHODS

Two samples of 300 people valued nine states of alcohol misuse. LE and WTP were used in sample 1 and 2, respectively. The ability to discriminate between methods was tested. Regression models were performed to estimate the preference weights of dimensions. Several values of WTP-Q were obtained by combining the estimated values from both samples.

RESULTS

LE and WTP produce the same ranking of states but LE is more sensitive. The estimated impact of the nine states ranges between 0.91 and 0.22 QALYs, and the WTP for avoiding them ranges between €10,444 and €4132. WTP-Q varies between €11,473 and €19,092 when the mean values of the states are used. The WTP-Q tends to decrease with the severity.

CONCLUSIONS

Although LE and WTP provide values for cost-utility and cost-benefit analyses, respectively, LE seems to be preferable for measuring the impact of alcohol disorders. As the lower sensitivity of WTP seems to explain a WTP-Q decrease with severity, more research is needed before recommending the use of different WTP-Q values.

Assessing the Patient-Perceived Monetary Value of Patient-Reported Outcome Improvement for Patients With Chronic Knee Conditions

PURPOSE

The high cost of orthopaedic care has attracted criticism in the current value-based health care environment. The objective of this work was to assess the properties of a willingness to pay (WTP)-based approach to estimate the monetary value that patients place on health improvements in chronic knee conditions following orthopaedic treatment.

METHODS

A sample of patients with a chronic knee condition were surveyed between January and May of 2018 at a large orthopaedic practice. Each patient provided their WTP for restoration to ideal knee health and completed the Single Assessment Numerical Evaluation (SANE) to describe their baseline knee state. Average WTP was calculated for the total sample and stratified by income, age, and baseline SANE (for which 0 is the worst and 100 is the best) levels. The patient-perceived monetary value of each unit of SANE improvement was assessed.

RESULTS

The study sample included 86 patients seeking orthopaedic care for a chronic knee condition. Mean baseline SANE score was 45.5 (standard deviation: 25.0). Mean WTP to obtain ideal knee function from baseline was $18,704 (standard deviation: $18,040). For the full sample, patients valued a 1-unit improvement in SANE score at $291.1 (β: 291.1; P<0.05). The amount of money patients were willing to pay to achieve ideal knee function varied with age, income, and baseline knee state.

CONCLUSIONS

Patients appear to highly value improvement in chronic knee conditions. Willingness-to-pay survey results appear to track expected variation in patient outcome valuation by income and baseline knee condition and could be a valuable approach to assess value-based care in orthopaedics.

Comparing the Noncomparable: The Need for Equivalence Measures That Make Sense in Health-Economic Evaluations

BACKGROUND

The popularity of quality-adjusted life years (QALYs) has been resistant to concerns about validity and reliability. Utility-theoretic outcome equivalents are widely used in other areas of applied economics. Equivalence values can be derived for time, money, risk, and other metrics. These equivalence measures preserve all available information about individual preferences and are valid measures of individual welfare changes.

OBJECTIVE

The objective of this study was to derive alternative generalized equivalence measures from first principles and illustrate their application in an empirical comparative-effectiveness example.

METHODS

We specify a general-equilibrium model incorporating neoclassical utility functions, health production function, severity-duration preferences, and labor-market tradeoff function. The empirical implementation takes advantage of discrete-choice experiment methods that are widely accepted in other areas of applied economics and increasingly in health economics. We illustrate the practical significance of restrictive QALY assumptions using comparative-effectiveness results based on both QALYs and estimates of welfare-theoretic time-equivalent values for anti-tumor necrosis factor and prolonged corticosteroid treatments for Crohn's disease in three distinct preference classes.

RESULTS

The QALY difference between the two treatments is 0.2 months, while time-equivalent values range between 0.5 and 1.3 months for aggregate and class-specific differences. Thus, the QALY-based analysis understates welfare-theoretic values by 60%-85%.

CONCLUSION

These results suggest that using disease-specific equivalence values offer a meaningful alternative to QALYs to compare global outcomes across treatments. The equivalence values approach is consistent with principles of welfare economics and offers several features not represented in QALYs, including accounting for preference nonlinearities in disease severity and duration, inclusion of preference-relevant nonclinical healthcare factors, representing preferences of clinically-relevant patient subpopulations, and including utility losses related to risk aversion.

Impact of herpes zoster and postherpetic neuralgia on the quality of life of Germans aged 50 or above

Background

Herpes zoster (HZ) is a painful dermatomal rash caused by reactivation of latent varicella zoster virus surviving in the patient’s sensory ganglia after a previous episode of varicella. The incidence of HZ increases markedly with age as does the proportion of HZ patients who develop postherpetic neuralgia (PHN) with often severe and debilitating pain persisting for months and even years.

This prospective study aimed to assess the impact of HZ and PHN on the quality of life (QoL) of individuals aged ≥ 50 years in Germany.

Methods

Patients were recruited when consulting primary care physicians for a first HZ episode. PHN was defined as a ‘worst’ pain score ≥ 3 on the Zoster Brief Pain Inventory (ZBPI) scale persisting or appearing 90 days or more after rash onset. PHN-cases were followed for up to nine months after rash onset. The interference of pain with patients’ ability to carry out normal activities was assessed by the ZBPI activities of daily living (ADL) scale and QoL by the EuroQoL five-dimension scale (EQ-5D) utility score.

Results

Of 513 patients enrolled, 61 (11.9%) developed PHN. At HZ onset, the mean ZBPI worst pain score of all patients was 5.1, the least square (LS)means estimates of the ZBPI ADL and EQ-5D utility scores were 2.970 and 0.740, respectively. Over three months follow-up, the pain scores decreased and the QoL increased monotonically across all age groups. At Day 90, the mean ZBPI worst pain score of the PHN patients was 4.4, while the LSmeans estimates of the ZBPI ADL and EQ-5D utility scores were 2.899 and 0.826, respectively. For patients with PHN persisting at nine months, the pain scores and QoL remained unchanged over the six months following the development of PHN.

Conclusion

HZ and PHN had a substantial impact on the patients’ QoL and ability to function in their normal activities. There was a clear association in time between the evolution of pain and estimated QoL. The impact on ADL and QoL did not vary with age.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3395-z) contains supplementary material, which is available to authorized users.

The impact of demographic changes, exogenous boosting and new vaccination policies on varicella and herpes zoster in Italy: a modelling and cost-effectiveness study

BACKGROUND

The present study aims to evaluate the cost-effectiveness of the newly introduced varicella and herpes zoster (HZ) vaccination programmes in Italy. The appropriateness of the introduction of the varicella vaccine is highly debated because of concerns about the consequences on HZ epidemiology and the expected increase in the number of severe cases in case of suboptimal coverage levels.

METHODS

We performed a cost-utility analysis based on a stochastic individual-based model that considers realistic demographic processes and two different underlying mechanisms of exogenous boosting (temporary and progressive immunity). Routine varicella vaccination is given with a two-dose schedule (15 months, 5-6 years). The HZ vaccine is offered to the elderly (65 years), either alone or in combination with an initial catch-up campaign (66-75 years). The main outcome measures are averted cases and deaths, costs per quality-adjusted life years gained, incremental cost-effectiveness ratios, and net monetary benefits associated with the different vaccination policies.

RESULTS

Demographic processes have contributed to shaping varicella and HZ epidemiology over the years, decreasing varicella circulation and increasing the incidence of HZ. The recent introduction of varicella vaccination in Italy is expected to produce an enduring reduction in varicella incidence and, indirectly, a further increase of HZ incidence in the first decades, followed by a significant reduction in the long term. However, the concurrent introduction of routine HZ vaccination at 65 years of age is expected to mitigate this increase and, in the longer run, to reduce HZ burden to its minimum. From an economic perspective, all the considered policies are cost-effective, with the exception of varicella vaccination alone when considering a time horizon of 50 years. These results are robust to parameter uncertainties, to the two different hypotheses on the mechanism driving exogenous boosting, and to different demographic projection scenarios.

CONCLUSIONS

The recent introduction of a combined varicella and HZ vaccination programme in Italy will produce significant reductions in the burden of both diseases and is found to be a cost-effective policy. This programme will counterbalance the increasing trend of zoster incidence purely due to demographic processes.

Sponsorship Bias in Base-Case Values and Uncertainty Bounds of Health Economic Evaluations? A Systematic Review of Herpes Zoster Vaccination

BACKGROUND

New health technologies are more likely adopted when they have lower incremental cost-effectiveness ratios (ICERs) and/or when their ICER is presented with more certainty. Industry-funded (IF) health economic evaluations use often more favorable base-case values, leading to more favorable conclusions.

PURPOSE

To study whether IF health economic evaluations of varicella-zoster virus vaccination in the elderly use more favorable base-case values and account for less uncertainty than non-industry-funded (NIF) evaluations.

METHODS

DATA SOURCE

PubMed. Data extracted: funding source; incremental cost per quality-adjusted life year (QALY) gained; vaccine price; study quality score; base-case values, uncertainty ranges, and data sources for influential parameters: duration of vaccine protection, utility loss due to herpes zoster (HZ) disease, percentage of HZ patients developing postherpetic neuralgia (PHN), and duration of PHN.

DATA SYNTHESIS

qualitative comparisons; Fisher exact test for differences in study quality score and 1-sided Mann-Whitney U tests for differences in base-case values and uncertainty ranges.

RESULTS

Despite using the same data sources, IF studies ( n = 10) assume a longer duration of vaccine protection ( U = 56, P = 0.03), have a higher percentage of HZ patients developing PHN ( U = 22/33, P = 0.02/0.03 for ages 60-64/65-69), and tend to use higher HZ utility loss than NIF studies ( n = 11) for their baseline. IF studies show lower ICERs given similar or even higher vaccine prices than NIF studies, consider less uncertainty around the duration of vaccine protection ( U = 8, P < 0.001), and tend to use less uncertainty around the duration of PHN. Yet their quality has been rated equally well, using current standard quality rating tools.

CONCLUSION

Researchers and decision makers should be aware of potential sponsorship bias in health economic evaluations, especially in the way source data are used to specify base-case values and uncertainty ranges.

Herpes zoster vaccine: A health economic evaluation for Switzerland

Herpes zoster (HZ) or “shingles” results from a reactivation of the varicella zoster virus (VZV) acquired during primary infection (chickenpox) and surviving in the dorsal root ganglia. In about 20% of cases, a complication occurs, known as post-herpetic neuralgia (PHN). A live attenuated vaccine against VZV is available for the prevention of HZ and subsequent PHN. The present study aims to update an earlier evaluation estimating the cost-effectiveness of the HZ vaccine from a Swiss third party payer perspective. It takes into account updated vaccine prices, a different age cohort, latest clinical data and burden of illness data. A Markov model was developed to simulate the lifetime consequences of vaccinating 15% of the Swiss population aged 65–79 y. Information from sentinel data, official statistics and published literature were used. Endpoints assessed were number of HZ and PHN cases, quality-adjusted life years (QALYs), costs of hospitalizations, consultations and prescriptions. Based on a vaccine price of CHF 162, the vaccination strategy accrued additional costs of CHF 17,720,087 and gained 594 QALYs. The incremental cost-effectiveness ratio (ICER) was CHF 29,814 per QALY gained. Sensitivity analyses showed that the results were most sensitive to epidemiological inputs, utility values, discount rates, duration of vaccine efficacy, and vaccine price. Probabilistic sensitivity analyses indicated a more than 99% chance that the ICER was below 40,000 CHF per QALY. Findings were in line with existing cost-effectiveness analyses of HZ vaccination. This updated study supports the value of an HZ vaccination strategy targeting the Swiss population aged 65–79 y.

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.

Willingness to pay for hypothetical malaria vaccines in rural Burkina Faso

Aims: This study aims to set priorities for anti-disease malaria vaccines by determining community preference in a hyperendemic area. Methods: A bidding game technique was used to elucidate willingness to pay in rural Burkina Faso and 2,326 adults were interviewed. Results: It is shown that there are significant differences between community preference for an anti-disease vaccine aimed at reducing pathology in pregnant women, and for a vaccine directed against childhood malaria. While the target population was willing to pay CFAfr 2101 for a vaccine against maternal malaria, its members were prepared to pay only CFAfr 1433 for a vaccine against childhood malaria. Conclusions: Whilst it is increasingly likely that anti-disease malaria vaccines will become available in the foreseeable future, lessons from the past suggest that a lack of acceptance and support from the intended recipients may lead to less than optimal compliance, and hence efficacy. For the planning of vaccine development and application strategies, it is therefore highly important to take community views into account. Here it is argued that such information could help researchers and funding agencies to set priorities for future vaccine research.

Impact of Model, Methodological, and Parameter Uncertainty in the Economic Analysis of Vaccination Programs

Guidelines for economic evaluations insist that the sensitivity of model results to alternative parameter values should be thoroughly explored. However, differences in model construction and analytical choices (such as the choice of a cost-effectiveness or cost-benefit framework) also introduce uncertainty in results, though these are rarely subjected to a thorough sensitivity analysis. In this article, the authors quantify the effect of model, methodological, and parameter uncertainty, taking varicella vaccination as an example. They used 3 different models (a static model, a dynamic model that only looks at the effect of vaccination on varicella, and a dynamic model that also assesses the implications of vaccination for zoster epidemiology) and 2 forms of analysis (cost-benefit and cost-utility). They also varied the discount rate and time frame of analysis. Probabilistic sensitivity analyses were performed to estimate the impact of parameter uncertainty. In their example, model and methodological choice had a profound effect on estimated cost-effectiveness, but parameter uncertainty played a relatively minor role. Under cost-utility analysis, the probabilistic sensitivity analysis suggested that there was a near certainty that vaccination dominates no vaccination, or the other way around, depending on model choice and perspective. Under cost-benefit analysis, vaccination always appeared to be attractive. Thus, the authors clearly show that model and methodological assumptions can have greater impact on results than parameter estimates, although sensitivity analyses are rarely performed on these sources of uncertainty.

Economic evaluation in chronic pain: a systematic review and de novo flexible economic model

There is unmet need in patients suffering from chronic pain, yet innovation may be impeded by the difficulty of justifying economic value in a field beset by data limitations and methodological variability. A systematic review was conducted to identify and summarise the key areas of variability and limitations in modelling approaches in the economic evaluation of treatments for chronic pain. The results of the literature review were then used to support the development of a fully flexible open-source economic model structure, designed to test structural and data assumptions and act as a reference for future modelling practice. The key model design themes identified from the systematic review included: time horizon; titration and stabilisation; number of treatment lines; choice/ordering of treatment; and the impact of parameter uncertainty (given reliance on expert opinion). Exploratory analyses using the model to compare a hypothetical novel therapy versus morphine as first-line treatments showed cost-effectiveness results to be sensitive to structural and data assumptions. Assumptions about the treatment pathway and choice of time horizon were key model drivers. Our results suggest structural model design and data assumptions may have driven previous cost-effectiveness results and ultimately decisions based on economic value. We therefore conclude that it is vital that future economic models in chronic pain are designed to be fully transparent and hope our open-source code is useful in order to aspire to a common approach to modelling pain that includes robust sensitivity analyses to test structural and parameter uncertainty.

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.

Cost-effectiveness analysis of a vaccination program for the prevention of herpes zoster and post-herpetic neuralgia in adults aged 50 and over in Germany

Herpes zoster (HZ; shingles) is a common viral disease that affects the nerves and surrounding skin causing a painful dermatomal rash and leading to debilitating complications such as, mainly, post-herpetic neuralgia (PHN). Currently, there is no effective treatment for HZ and PHN. The objective of this study was to assess the cost-effectiveness of a HZ vaccination program in Germany. An existing Markov Model was adapted to the German healthcare setting to compare a vaccination policy to no vaccination on a lifetime time-horizon, considering 2 scenarios: vaccinating people starting at the age of 50 or at the age of 60 years, from the perspective of the statutory health insurance (SHI) and the societal perspective. According to the perspective, vaccinating 20% of the 60+ German population resulted in 162,713 to 186,732 HZ and 31,657 to 35,793 PHN cases avoided. Corresponding incremental cost-effectiveness ratios (ICER) were 39,306 €/QALY from the SHI perspective and 37,417 €/QALY from a societal perspective. Results for the 50+ German population ranged from 336,468 to 394,575 HZ and from 48,637 to 56,087 PHN cases avoided from the societal perspective. Corresponding ICER were 39,782 €/QALY from a SHI perspective and 32,848 €/QALY from a societal perspective. Sensitivity analyses showed that results are mainly impacted by discount rates, utility values and use of alternative epidemiological data.The model indicated that a HZ vaccination policy in Germany leads to significant public health benefits and could be a cost-effective intervention. The results were robust and consistent with local and international existing literature.

A systematic review of studies eliciting willingness-to-pay per quality-adjusted life year: does it justify CE threshold?

BACKGROUND

A number of studies have been conducted to estimate willingness to pay (WTP) per quality-adjusted life years (QALY) in patients or general population for various diseases. However, there has not been any systematic review summarizing the relationship between WTP per QALY and cost-effectiveness (CE) threshold based on World Health Organization (WHO) recommendation.

OBJECTIVE

To systematically review willingness-to-pay per quality-adjusted-life-year (WTP per QALY) literature, to compare WTP per QALY with Cost-effectiveness (CE) threshold recommended by WHO, and to determine potential influencing factors.

METHODS

We searched MEDLINE, EMBASE, Psyinfo, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Center of Research Dissemination (CRD), and EconLit from inception through 15 July 2014. To be included, studies have to estimate WTP per QALY in health-related issues using stated preference method. Two investigators independently reviewed each abstract, completed full-text reviews, and extracted information for included studies. We compared WTP per QALY to GDP per capita, analyzed, and summarized potential influencing factors.

RESULTS

Out of 3,914 articles founded, 14 studies were included. Most studies (92.85%) used contingent valuation method, while only one study used discrete choice experiments. Sample size varied from 104 to 21,896 persons. The ratio between WTP per QALY and GDP per capita varied widely from 0.05 to 5.40, depending on scenario outcomes (e.g., whether it extended/saved life or improved quality of life), severity of hypothetical scenarios, duration of scenario, and source of funding. The average ratio of WTP per QALY and GDP per capita for extending life or saving life (2.03) was significantly higher than the average for improving quality of life (0.59) with the mean difference of 1.43 (95% CI, 1.81 to 1.06).

CONCLUSION

This systematic review provides an overview summary of all studies estimating WTP per QALY studies. The variation of ratio of WTP per QALY and GDP per capita depended on several factors may prompt discussions on the CE threshold policy. Our research work provides a foundation for defining future direction of decision criteria for an evidence-informed decision making system.

The effect of measles on health-related quality of life: a patient-based survey

Background

Measles is a highly contagious and potentially fatal illness preventable through vaccination. Outbreaks in the UK and many other European countries have been increasing over recent years, with over 3,207 laboratory-confirmed cases reported by Public Health England from January 2012 to the end of June 2013. To aid rational decision making regarding measles control versus other use of healthcare resources, it is important to measure the severity of measles in units that are comparable to other diseases. The standard metric for this in the UK is the quality-adjust life year (QALY). To our knowledge, the impact of measles on health-related quality of life (HRQoL) in terms of QALYs has not been quantified.

Methods and Findings

Individuals with confirmed measles were sent questionnaires requesting information on the short-term impact of the illness on their HRQoL using the EuroQol EQ-5D-3L questionnaire. HRQoL was reported for the day the questionnaire was received, the worst day of infection and at follow-up three weeks later. 507 questionnaires were sent to individuals with confirmed measles with 203 returned (40%). The majority of respondents were not vaccinated. The mean time off work or school was 9.6 days. The mean duration of perceived illness was 13.8 days. The mean number of QALYs lost was 0.019 (equivalent to 6.9 days). The overall burden of disease in terms of QALYs lost in England based on the total number of confirmed cases in the twelve month period from 1^st June 2012 was estimated to be 44.2 QALYs.

Conclusion

The short-term impact of measles infection on HRQoL is substantial, both at the level of the individual patient and in terms of the overall disease burden. This is the first attempt to quantify QALY-loss due to measles at a population level, and provides important parameters to guide future intervention and control measures.

Is herpes zoster vaccination likely to be cost-effective in Canada?

OBJECTIVES

To synthesize the current literature detailing the cost-effectiveness of the herpes zoster (HZ) vaccine, and to provide Canadian policy-makers with cost-effectiveness measurements in a Canadian context.

METHODS

This article builds on an existing systematic review of the HZ vaccine that offers a quality assessment of 11 recent articles. We first replicated this study, and then two assessors reviewed the articles and extracted information on vaccine effectiveness, cost of HZ, other modelling assumptions and QALY estimates. Then we transformed the results into a format useful for Canadian policy decisions. Results expressed in different currencies from different years were converted into 2012 Canadian dollars using Bank of Canada exchange rates and a Consumer Price Index deflator. Modelling assumptions that varied between studies were synthesized. We tabled the results for comparability.

SYNTHESIS

The Szucs systematic review presented a thorough methodological assessment of the relevant literature. However, the various studies presented results in a variety of currencies, and based their analyses on disparate methodological assumptions. Most of the current literature uses Markov chain models to estimate HZ prevalence. Cost assumptions, discount rate assumptions, assumptions about vaccine efficacy and waning and epidemiological assumptions drove variation in the outcomes. This article transforms the results into a table easily understood by policy-makers.

CONCLUSION

The majority of the current literature shows that HZ vaccination is cost-effective at the price of $100,000 per QALY. Few studies showed that vaccination cost-effectiveness was higher than this threshold, and only under conservative assumptions. Cost-effectiveness was sensitive to vaccine price and discount rate.

Health economic evaluation of vaccination strategies for the prevention of herpes zoster and postherpetic neuralgia in Germany

BACKGROUND

Herpes zoster (HZ) is a self-limiting painful skin rash affecting mostly individuals from 50 years of age. The main complication is postherpetic neuralgia (PHN), a long-lasting pain after rash has resolved. A HZ-vaccine has recently been licensed in Europe for individuals older than 50 years. To support an informed decision-making for a potential vaccination recommendation, we conducted a health economic evaluation to identify the most cost-effective vaccination strategy.

METHODS

We developed a static Markov-cohort model, which compared a vaccine-scenario with no vaccination. The cohort entering the model was 50 years of age, vaccinated at age 60, and stayed over life-time in the model. Transition probabilities were based on HZ/PHN-epidemiology and demographic data from Germany, as well as vaccine efficacy (VE) data from clinical trials. Costs for vaccination and HZ/PHN-treatment (in Euros; 2010), as well as outcomes were discounted equally with 3% p.a. We accounted results from both, payer and societal perspective. We calculated benefit-cost-ratio (BCR), number-needed-to-vaccinate (NNV), and incremental cost-effectiveness ratios (ICERs) for costs per HZ-case avoided, per PHN-case avoided, and per quality-adjusted life-year (QALY) gained. Different target age-groups were compared to identify the most cost-effective vaccination strategy. Base-case-analysis as well as structural, descriptive-, and probabilistic-sensitivity-analyses (DSA, PSA) were performed.

RESULTS

When vaccinating 20% of a cohort of 1 million 50 year old individuals at the age of 60 years, approximately 20,000 HZ-cases will be avoided over life-time. The NNV to avoid one HZ (PHN)-case was 10 (144). However, with a BCR of 0.34 this vaccination-strategy did not save costs. The base-case-analysis yielded an ICER of 1,419 (20,809) Euros per avoided HZ (PHN)-case and 28,146 Euros per QALY gained. Vaccination at the age of 60 was identified in most (sensitivity) analyses to be the most cost-effective vaccination strategy. In DSA, vaccine price and VE were shown to be the most critical input-data.

CONCLUSIONS

According to our evaluation, HZ-vaccination is expected to avoid HZ/PHN-cases and gain QALYs to higher costs. However, the vaccine price had the highest impact on the ICERs. Among different scenarios, targeting individuals aged 60 years seems to represent the most cost-effective vaccination-strategy.

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.

Cost-effectiveness of vaccination of the elderly against herpes zoster in The Netherlands

BACKGROUND

Each year a substantial number of Dutch elderly suffers from herpes zoster (HZ), caused by the reactivation of the varicella zoster virus (VZV). A potential complication of HZ is postherpetic neuralgia (PHN) which results in a prolonged loss of quality of life. A large randomized clinical trial, labelled the Shingles Prevention study (SPS), demonstrated that a live attenuated VZV vaccine can reduce the incidence of HZ and PHN.

OBJECTIVE

We aimed to estimate the incremental cost-effectiveness ratio (ICER) of vaccination of the elderly against HZ versus no such vaccination in The Netherlands.

METHODS

A cohort model was developed to compare the costs and effects in a vaccinated and a non-vaccinated age- and gender-stratified cohort of immune-competent elderly. Vaccination age was varied from 60 to 75 years. Data from published literature such as the SPS were used for transition probabilities. The study was performed from the societal as well as the health care payer's perspective and results were expressed in euros per quality-adjusted life year (QALY) gained.

RESULTS

In the base case, we estimated that vaccination of a cohort of 100,000 60-year-olds would prevent 4136 cases of HZ, 305 cases of PHN resulting in a QALY-gain of 209. From the societal perspective, a total of €1.9 million was saved and the ICER was €35,555 per QALY gained when a vaccine price of €87 was used. Vaccination of women resulted in a lower ICER than vaccination of men (€33,258 vs. €40,984 per QALY gained). The vaccination age with the most favourable ICER was 70 years (€29,664 per QALY gained). Parameters with a major impact on the ICER were the vaccine price and HZ incidence rates. In addition, the model was sensitive to utility of mild pain, vaccine efficacy at the moment of uptake and the duration of protection induced by the vaccine.

CONCLUSION

Vaccination against HZ might be cost-effective for ages ranging from 60 to 75 when a threshold of €50,000 per QALY gained would be used, at €20,000 per QALY this might not be the case. Additional information on the duration of vaccine-protection is needed to further optimize cost-effectiveness estimations.

A welfare economic approach to measure outcomes in stuttering: comparing willingness to pay and quality adjusted life years

PURPOSE

The purpose of this study was to compare two welfare outcome measures, willingness to pay (WTP) and quality adjusted life years (QALYs) gained, to measure outcomes in stuttering.

METHOD

Seventy-eight adult participants (74 nonstuttering and 4 persons with stuttering) completed one face-to-face structured interview regarding how much they would be willing to pay to alleviate severe stuttering in three interventions of varying impact. These data were compared with QALYs gained as calculated from time trade off (TTO) and standard gamble (SG) data.

RESULTS

Mean (median) WTP bids ranged from US $16,875 (8000), for an intervention resulting in improvement from severe stuttering to mild stuttering, to US $41,844 (10,000) for an intervention resulting in a cure of severe stuttering. These data were consistent with mean changes in QALYs for the same stuttering interventions ranging from 2.19 (using SG) to 18.42 (using TTO).

CONCLUSIONS

This study presents the first published WTP and QALY data for stuttering. Results were consistent with previous cost-of-illness data for stuttering. Both WTP and QALY measures were able to quantify the reduction in quality of life that occurs in stuttering, and both can be used to compare the gains that might be achieved by different interventions. It is widely believed that stuttering can cause reduced quality of life for some speakers; the introduction into this field of standardized metrics for measuring quality of life is a necessary step for transparently weighing the costs and consequences of stuttering interventions in economic analyses.

EDUCATIONAL OBJECTIVES

The reader will be able to (a) describe the underlying theoretical foundations for willingness to pay and quality adjusted life years, (b) describe the application of willingness to pay and quality adjusted life years for use in economic analyses, (c) compare and contrast the value of willingness to pay and quality adjusted life years in measuring the impact of stuttering treatment on quality of life, (d) interpret quality adjusted life years, and (e) interpret willingness to pay data.

Assessment of respondent acceptability for preference measures in stuttering

PURPOSE

To assess the feasibility of using one or more of four standard economic preference measures to assess health-related quality of life in stuttering, by assessing respondents' views of the acceptability of those measures.

METHOD AND RESULTS

A graphic positioning scale approach was used with 80 adults to assess four variables previously defined as reflecting the construct of respondent acceptability (difficulty of decision making, clarity of text, reasonableness for decision making, and comfort in decision making) for four types of preference measurement approaches (rating scale, standard gamble, time trade-off, and willingness to pay). A multivariate repeated measures analysis of variance (p<.001) and follow-up univariate repeated measures analyses of variance (all p<.01) were all significant, indicating that respondents perceived differences among the preference measurement methods on all four acceptability variables.

CONCLUSION

The rating scale was perceived as the easiest, clearest, most reasonable, and most comfortable tool, but it is not a measure of utility (an economic term for desirability or worth). If utility is the objective, such as for cost-utility analyses in stuttering, then the present results suggest the use of standard gamble (rather than time trade-off). These results also support the use of willingness to pay assessments for cost-benefit analyses in stuttering. These findings supplement results previously obtained for other chronic conditions.

LEARNING OUTCOMES

The reader will be able to: (1) describe how four standard economic preference measures [rating scale (RS), time trade-off (TTO), standard gamble (SG), and willingness to pay (WTP)] can be used in economic analyses; (2) describe how RS, TTO, SG and WTP can be measured; and (3) describe how respondents perceive the use of RS, TTO, SG and WTP in measuring changes in stuttering.

Increasing access to modern contraceptives: the potential role of community solidarity through altruistic contributions

Background

There is an urgent need for universal access to modern contraceptives in Nigeria, to facilitate the achievement of the Millennium Development Goals and other national goals. This study provides information on the potential role of community solidarity in increasing access to contraceptives for the most-poor people through exploration of the role of altruism by determining level of altruistic willingness to pay (WTP) for modern contraceptives across different geographic contexts in Nigeria.

Methods

It was a cross-sectional national survey which took place in six states spread across the six-geopolitical zones of the country. In each state, an urban and a rural area were selected for the study, giving a total of 6 urban and 6 rural sites. A pre-tested interviewer-administered questionnaire was used to collect information from at least 720 randomly selected householders from each state. The targeted respondent in a household was a female primary care giver of child bearing age (usually the wives), or in her absence, another female household member of child bearing age. A scenario on altruistic WTP was presented before the value was elicited using a binary with open-ended follow-up question format. Test of validity of elicited altruistic WTP was undertaken using Tobit regression.

Findings

More than 50 % of the respondents across all the states were willing to contribute some money so that the very poor would be provided with modern contraceptives. The average amount of money that people were willing to contribute annually was 650 Naira (US$4.5). Mean altruistic WTP differed across SES quintiles and urban-rural divide (p < .01). Multiple regression analysis showed that age was negatively related to altruistic WTP (p < 0.05). However, years of schooling, being employed by government or being a big business person, prior experience of paying for contraceptives and socioeconomic status had statistically significant effects on altruistic WTP (p < 0.05).

Conclusion

There is room for community solidarity to ensure that the very poor benefit from modern contraceptives and assure universal coverage with modern contraceptives. The factors that determine altruistic WTP should be harnessed to ensure that altruistic contributions are actually made. The challenge will be how to collect and pool the altruistic contributions for purchasing and delivering modern contraceptives to the most-poor, within the context of community financing.

Willingness to pay in dermatology: assessment of the burden of skin diseases

Willingness to pay (WTP) is a monetary, preference-based, burden-of-disease measure with a potential role in dermatology, where many conditions are temporary and/or mild, and many treatments are inexpensive and one might be able to imagine paying out of pocket. We assessed construct validity by interviewing 254 consecutive dermatology patients at Stanford Medical Center, Grady Hospital, and Parkland Hospital. Instruments asked about an individual's own health status and elicited WTP, time-trade-off (TTO) utilities, and health status quality of life (QOL). We measured WTP cure (short treatment course to eliminate disease) and WTP control (lifelong medication). Our data indicate greater construct validity in non-Medicaid (n=163) than Medicaid (n=91) patients. Non-Medicaid subjects had greater WTP as percent of income for cure (median: 2%) than control (median: 1.6%), P<0.01; Medicaid WTP amounts for control and cure did not differ. Non-Medicaid subjects with verrucae had little QOL impact, no measurable burden by TTO, and a correspondingly low WTP. Medicaid subjects with basal cell carcinoma had a strong, negative QOL impact and high burden by TTO, but had relatively moderate WTP. WTP appears promising in certain income categories. More studies are needed for conclusions about specific diagnoses.

Disentangling WTP per QALY data: different analytical approaches, different answers

A large random sample of the Danish general population was asked to value health improvements by way of both the time trade-off elicitation technique and willingness-to-pay (WTP) using contingent valuation methods. The data demonstrate a high degree of heterogeneity across respondents in their relative valuations on the two scales. This has implications for data analysis. We show that the estimates of WTP per QALY are highly sensitive to the analytical strategy. For both open-ended and dichotomous choice data we demonstrate that choice of aggregated approach (ratios of means) or disaggregated approach (means of ratios) affects estimates markedly as does the interpretation of the constant term (which allows for disproportionality across the two scales) in the regression analyses. We propose that future research should focus on why some respondents are unwilling to trade on the time trade-off scale, on how to interpret the constant value in the regression analyses, and on how best to capture the heterogeneity in preference structures when applying mixed multinomial logit.

Cost-effectiveness of vaccination against herpes zoster in adults aged over 60 years in Belgium

AIM

To assess the cost-effectiveness of vaccinating all or subgroups of adults aged 60 to 85 years against herpes zoster.

METHODS

A deterministic compartmental static model was developed (in freeware R), in which cohorts can acquire herpes zoster according to their age in years. Surveys and database analyses were conducted to obtain as much as possible Belgian age-specific estimates for input parameters. Direct costs and Quality-Adjusted Life-Year (QALY) losses were estimated as a function of standardised Severity Of Illness (SOI) scores (i.e. as a function of the duration and severity of herpes zoster disease).

RESULTS

Uncertainty about the average SOI score for a person with herpes zoster, the duration of protection from the vaccine, and the population that can benefit from the vaccine, exerts a major impact on the results: under assumptions least in favour of vaccination, vaccination is not cost-effective (i.e. incremental cost per QALY gained >€48,000 for all ages considered) at the expected vaccine price of €90 per dose. At the same price, but under assumptions most in favour of vaccination, vaccination is found to be cost-effective (i.e. incremental cost per QALY gained <€5500 for all ages considered). Vaccination of age cohort 60 seems more cost-effective than vaccination of any older age cohort in Belgium.

DISCUSSION

If the vaccine price per dose drops to €45, HZ vaccination of adults aged 60-64 years is likely to be cost-effective in Belgium, even under assumptions least in favour of vaccination. Unlike previous studies, our analysis acknowledged major methodological and model uncertainties simultaneously and presented outcomes for 26 different target ages at which vaccination can be considered (ages 60-85).

Diminishing willingness to pay per quality-adjusted life year: valuing acute foodborne illness

We design and conduct a stated-preference survey to estimate willingness to pay (WTP) to reduce foodborne risk of acute illness and to test whether WTP is proportional to the corresponding gain in expected quality-adjusted life years (QALYs). If QALYs measure utility for health, then economic theory requires WTP to be nearly proportional to changes in both health quality and duration of illness and WTP could be estimated by multiplying the expected change in QALYs by an appropriate monetary value. WTP is elicited using double-bounded, dichotomous-choice questions in which respondents (randomly selected from the U.S. general adult population, n = 2,858) decide whether to purchase a more expensive food to reduce the risk of foodborne illness. Health risks vary by baseline probability of illness, reduction in probability, duration and severity of illness, and conditional probability of mortality. The expected gain in QALYs is calculated using respondent-assessed decrements in health-related quality of life if ill combined with the duration of illness and reduction in probability specified in the survey. We find sharply diminishing marginal WTP for severity and duration of illness prevented. Our results suggest that individuals do not have a constant rate of WTP per QALY, which implies that WTP cannot be accurately estimated by multiplying the change in QALYs by an appropriate monetary value.

Economic evaluation of a vaccine for the prevention of herpes zoster and post-herpetic neuralgia in older adults in Switzerland

BACKGROUND

A life-attenuated vaccine aimed at preventing herpes zoster (HZ) and its main complication, post-herpetic neuralgia (PHN), will soon be available in Europe. The study's objective was to assess the clinical and economic impact of a vaccination program for adults aged 70-79 years in Switzerland.

RESULTS

A vaccination strategy compared to a no-vaccination resulted in lifetime incremental cost-effectiveness ratios (ICERs) of 25,538 CHF (23,646 USD) per QALY gained, 6,625 CHF (6,134 USD) per HZ case avoided, and 15,487 CHF (14,340 USD) per PHN3 case avoided under the third-party payer perspective. Sensitivity analyses showed that the model was most sensitive to the discount rates, HZ epidemiological data and vaccine price used.

METHODS

A Markov model, simulating the natural history of HZ and PHN and the lifetime effects of vaccination, previously developed for the UK was adapted to the Swiss context. The model includes several health states including good health, HZ, PHN, and death. HZ and PHN states reflected pain severity.

CONCLUSION

The model predicts clinical and economic benefits of vaccination in the form of fewer HZ and PHN cases and reductions in healthcare resource use. ICERs were within the commonly accepted thresholds in Switzerland, indicating that a HZ vaccination program would be considered a cost-effective strategy in the Swiss setting.

A methodological framework of preparing economic evidence for selection of medicines in the Chinese setting

Medicines are becoming a major component of health expenditure in China. Selection of effective and cost-effective medicines represents an important effort to improve medicines use. A guideline on cost-effectiveness studies has been available in China. This guideline, however, fails to be a practical tool to prepare and critically appraise economic evidence. This article discusses, in the Chinese context, the approach to integrating economic component into the medicines selection, and elaborates the methods of producing economic evidence, including conducing economic reviews and primary economic studies.

Methodological issues in the monetary valuation of benefits in healthcare

Economic evaluation is concerned with comparing the costs and benefits of competing healthcare interventions in order to efficiently allocate resources. Whilst valuing costs is important, the valuation of benefits represents one of the greatest challenges facing health economists. This review considers the different techniques available for the valuation of healthcare benefits in monetary terms, and more specifically the contingent valuation method and discrete choice experiments. This review identifies some of the key issues and debates that have been published in the literature concerning the application of the techniques to healthcare and highlights important areas for future research.

A health economic model for evaluating a vaccine for the prevention of herpes zoster and post-herpetic neuralgia in the UK

Background

A live-attenuated vaccine aimed at preventing herpes zoster (HZ) and its main complication, post-herpetic neuralgia (PHN) is available in Europe for immunocompetent adults aged 50 years and more. The study objective is to assess the cost effectiveness of a vaccination program for this population in the UK.

Methods

A state-transition Markov model has been developed to simulate the natural history of HZ and PHN and to estimate the lifetime effects of vaccination in the UK. Several health states are defined including good health, HZ, PHN, and death. HZ and PHN health states are further divided to reflect pain severity.

Results

The model predicts that a vaccination strategy for those aged over 50 years would lead to an incremental cost-effectiveness ratio of £13,077 per QALY gained from the NHS perspective, when compared to the current strategy of no vaccination. Age-group analyses show that the lowest ICERs (£10,984 and £10,275 for NHS) are observed when vaccinating people between 60-64 and 65-69 years of age. Sensitivity analyses showed that results are sensitive to the duration of vaccine protection, discount rate, utility decrements and pain severity split used.

Conclusions

Using the commonly accepted threshold of £30,000 per QALY gained in the UK, most scenarios of vaccination programmes preventing HZ and PHN, including the potential use of a repeat dose, may be considered cost-effective by the NHS, especially within the 60 to 69 age-groups.

Willingness to pay for allergy-vaccination among Danish patients with respiratory allergy

OBJECTIVE

The aim of this study was to elicit willingness to pay (WTP) for allergen-specific subcutaneous injection immunotherapy (SCIT) in a cohort of respondents suffering from allergic-rhinoconjunctivitis (a-RC)/asthma, and to investigate how patients self-select to SCIT according to need.

METHODS

A random sample of the general population was screened for a-RC/asthma and asked if they were willing to consider SCIT. They were asked to state their WTP for SCIT by way of a discrete choice question (DC-q), an open-ended WTP question (o-WTP-q), and questions relating to their sociodemographic background and the severity of their a-RC/asthma. The characteristics of respondents demanding SCIT were compared with the characteristics of respondents who have actually received SCIT to establish possible barriers to demand.

RESULTS

Our results suggest that respondents do well in self-selecting themselves to SCIT on the basis of need according to disease burden measured in terms of a-RC classification, number of contacts with a general practitioner, number of sick days, and potential quality-adjusted life-year loss. Mean WTP for SCIT was estimated at 655 euros (median, 267 euros) (o-WTP-q) and 903 euros (95 percent confidence limit, 348-1,459) (DC-q).

CONCLUSION

Characteristics of respondents, who consider SCIT and are willing to pay for SCIT, suggest that allergy sufferers select themselves appropriately according to need and not according to other characteristics, such as income or education. There is a significant discrepancy between those who hypothetically consider SCIT and those demanding SCIT in real life. This study suggests that there are barriers to entry related to age and education, but not to income.

The societal cost of tuberculosis: Tarrant County, Texas, 2002

PURPOSE

Cost analyses of tuberculosis (TB) in the United States have not included elements that may be prevented if TB were prevented, such as losses associated with TB-related disability, personal and other costs to society. Unmeasured TB costs lead to underestimates of the benefit of prevention and create conditions that could result in a resurgence of TB. We gathered data from Tarrant County, Texas, for 2002, to estimate the societal cost due to TB.

METHODS

We estimated societal costs due to the presence or suspicion of TB using known variable and fixed costs incurred to all parties. These include costs for infrastructure; diagnostics and surveillance; inpatient and outpatient treatment of active, suspected, and latent TB infection (LTBI); epidemiologic activities; personal costs borne by patients and by others for lost time, disability, and death; and the cost of secondary transmission. A discount rate of 3% was used.

RESULTS

During 2002, 108 TB cases were confirmed in Tarrant County, costing an estimated $40,574,953. The average societal cost per TB illness was $ 376,255. Secondary transmission created 47% and pulmonary impairment after TB created 35.4% of the total societal cost per illness.

CONCLUSIONS

Prior estimates have concluded that treatment costs constitute most (86%) TB-related expenditures. From a societal perspective treatment and other direct costs account for little (3.3%) of the full burden. These data predict that preventing infection through earlier TB diagnosis and treatment of LTBI and expanding treatment of LTBI may be the most feasible strategies to reduce the cost of TB.

Health economic evaluation of a vaccine for the prevention of herpes zoster (shingles) and post-herpetic neuralgia in adults in Belgium

OBJECTIVE

To determine the cost-effectiveness of vaccination against herpes zoster (HZ) and post-herpetic neuralgia (PHN) in individuals aged 60 years and older in Belgium.

METHODS

A Markov model was developed to compare the cost-effectiveness of vaccination with that of a policy of no vaccination. The model estimated the lifetime incidence and consequences of HZ and PHN using inputs derived from Belgian data, literature sources, and expert opinion. Cost-effectiveness was measured by the incremental cost-effectiveness ratio (ICER), expressed as cost per quality-adjusted life-year (QALY) gained.

RESULTS

Vaccination in individuals aged 60 years and older resulted in ICERs of €6,799 (third party payer perspective), €7,168 (healthcare perspective), and €7,137 (societal perspective). The number needed to vaccinate to prevent one case was 12 for HZ, and 35 or 36 for PHN depending on the definition used. Univariate sensitivity analyses produced ICERs of €4,959-19,052/QALY; duration of vaccine efficacy had the greatest impact on cost-effectiveness. Probabilistic sensitivity analysis showed at least a 94% probability of ICERs remaining below the unofficial €30,000 threshold.

DISCUSSION

Key strengths of the model are the combination of efficacy data from a pivotal clinical trial with country-specific epidemiological data and complete sensitivity analysis performed. Main limitations are the use of non country-specific PHN proportion and non Belgian disease-specific utilities. Results are comparable with those recently published.

CONCLUSIONS

HZ vaccination in individuals aged 60 years and older would represent a cost-effective strategy in Belgium.

"If you have the flu symptoms, your asymptomatic spouse may better answer the willingness-to-pay question". Evidence from a double-bounded dichotomous choice model with heterogeneous anchoring

The small sample size of contingent valuation (CV) surveys conducted in patients may have limited the use of the single-bounded (SB) dichotomous choice format which is recommended in environmental economics. In this paper, we explore two ways to increase the statistical efficiency of the SB format: (1) by the inclusion of proxies in addition to patients; (2) by the addition of a follow-up dichotomous question, i.e. the double-bounded (DB) dichotomous choice format. We found that patients (n=223) and spouses (n=64) answering on behalf of the patient had on average a similar willingness-to-pay for earlier alleviation of flu symptoms. However, a patient was significantly more likely to anchor his/her answer on the first bid as compared to a spouse. Finally, our original DB model with shift effect and heterogeneous anchoring reconciled the discrepancies found in willingness-to-pay statistics between SB and DB models in keeping with increased statistical efficiency.

Would people pay for text messaging health reminders?

The aim of this study is to determine the time and financial limitations that people would accept for using a telehealth service consisting of wireless text messaging reminders to improve adherence to a recommended healthy regimen. An empirical study based on a 1-month trial of a prototype system that studied adherence to a specified healthy behaviour was conducted. Fifty-one participants received daily cell phone text messaging reminders on taking one vitamin C pill daily for preventive reasons. At the end of the trial they answered a survey regarding their willingness to pay for and to stay with such a service, if offered. If usage were free, only 45% of the participants would continue to use it for a long indefinite period of time. If the usage were for a fee, 29% of the participants would use the service just a few weeks; 28% would use it an indefinite period of time if they could see its usefulness and if the cost were reasonable. The median amount indicated by the participants as a reasonable monthly fee for such a service was $5. Although the study did not evaluate perceived usefulness to use the telehealth service explicitly, a benefit perception proved to condition participant willingness to use the service and to pay for it, if necessary. If people perceive usefulness, they want to use the service, even for a fee. A free service would not be used if it is not perceived as beneficial.

The duration effect: a link between TTO and VAS values

The value of a health state may depend on how long an individual has had to endure the health state (i.e. hedonic load). In this paper, we test the constant proportionality (CP) assumption and determine the sign of relationship between duration and health state value for 42 health states using the nationally representative data from the United Kingdom Measurement and Valuation of Health study. The results reject the CP assumption and suggest that the relationship is negative for optimal health (i.e. fair innings argument) and that the relationship is positive for poorer health states (i.e. adaptation). We find no evidence of the maximum endurable time hypothesis using these data. This evidence on the duration effect has important implications for outcomes research and the economic evaluation of interventions.

Estimating the cost-effectiveness of vaccination against herpes zoster in England and Wales

A live-attenuated vaccine against herpes zoster (HZ) has been approved for use, on the basis of a large-scale clinical trial that suggests that the vaccine is safe and efficacious. This study uses a Markov cohort model to estimate whether routine vaccination of the elderly (60+) would be cost-effective, when compared with other uses of health care resources. Vaccine efficacy parameters are estimated by fitting a model to clinical trial data. Estimates of QALY losses due to acute HZ and post-herpetic neuralgia were derived by fitting models to data on the duration of pain by severity and the QoL detriment associated with different severity categories, as reported in a number of different studies. Other parameters (such as cost and incidence estimates) were based on the literature, or UK data sources. The results suggest that vaccination of 65 year olds is likely to be cost-effective (base-case ICER=pound20,400 per QALY gained). If the vaccine does offer additional protection against either the severity of disease or the likelihood of developing PHN (as suggested by the clinical trial), then vaccination of all elderly age groups is highly likely to be deemed cost-effective. Vaccination at either 65 or 70 years (depending on assumptions of the vaccine action) is most cost-effective. Including a booster dose at a later age is unlikely to be cost-effective.

Community and patient values for preventing herpes zoster

OBJECTIVES

The US Advisory Committee on Immunization Practices has recently recommended a new vaccine against herpes zoster (shingles) for routine use in adults aged > or =60 years. However, estimates of the cost effectiveness of this vaccine vary widely, in part because of gaps in the data on the value of preventing herpes zoster. Our aims were to (i) generate comprehensive information on the value of preventing a range of outcomes of herpes zoster; (ii) compare these values among community members and patients with shingles and post-herpetic neuralgia (PHN); and (iii) identify clinical and demographic characteristics that explain the variation in these values.

METHODS

Community members drawn from a nationally representative survey research panel (n = 527) completed an Internet-based survey using time trade-off and willingness-to-pay questions to value a series of scenarios that described cases of herpes zoster with varying pain intensities (on a scale of 0 to 10, where 0 represents no pain and 10 represents the worst imaginable pain) and duration (30 days to 1 year). Patients with shingles (n = 382) or PHN (n = 137) [defined as having symptoms for > or =90 days] from two large healthcare systems completed telephone interviews with similar questions to the Internet-based survey and also answered questions about their current experience with herpes zoster. We constructed generalized linear mixed models to evaluate the associations between demographic and clinical characteristics, the length and intensity of the health states and time trade-off and willingness-to-pay values.

RESULTS

In time trade-off questions, community members offered a mean of 89 (95% CI 24, 182) discounted days to avoid the least severe scenario (pain level of 3 for 1 month) and a mean of 162 (95% CI 88, 259) discounted days to avoid the most severe scenario (pain level of 8 for 12 months). Compared with patients with shingles, community members traded more days to avoid low-severity scenarios but similar numbers of days to avoid high-severity scenarios. Compared with patients with PHN, community members traded fewer days to avoid high-severity scenarios. In multivariate analyses, older age was the only characteristic significantly associated with higher time trade-off values. In willingness-to-pay questions, community members offered a mean of $US450 (95% CI 203, 893) to avoid pain of level 3 for 1 month and a mean of $US1384 (95% CI 873, 2050) [year 2005 values] to avoid pain of level 8 for 12 months. Community members traded less money than patients with either shingles or PHN to avoid both low- and high-severity scenarios (p-values <0.05 to <0.001). In multivariate models, male gender, higher income and having experienced shingles or PHN were associated with higher willingness to pay to avoid herpes zoster. When patients were asked to assign a value to avoiding their own case of herpes zoster, those with shingles assigned a mean of 67 days or $US2319, while those with PHN assigned a mean of 206 days or $US18 184. Both the time and monetary value traded were associated with the maximum intensity of the pain the individual had experienced, but neither was associated with the duration of the pain.

CONCLUSIONS

We believe that this study provides the most comprehensive information to date on the value individuals place on preventing herpes zoster, and it includes the only such valuation from nationally representative community members as well as patients with herpes zoster. Community members would trade substantial amounts of time or money to avoid herpes zoster, even in the least severe scenarios. The time trade-off results in this study may differ from those in other studies because of important differences in methods of assessing health utilities. Consideration of both community and patient perspectives is crucial to help decision makers fully determine the implications of their policies now that a vaccine against herpes zoster is available.

Evaluation of the cost-effectiveness in the United States of a vaccine to prevent herpes zoster and postherpetic neuralgia in older adults

CONTEXT

A live-attenuated varicella-zoster virus vaccine, demonstrated to reduce the incidence of herpes zoster (HZ) and postherpetic neuralgia (PHN) and the morbidity associated with incident HZ and its sequelae, has recently been approved for use in the United States (U.S.).

OBJECTIVE

To examine the potential value of zoster vaccine for society and payers. DESIGN, SETTING AND POPULATION: An age-specific decision analytic model was designed to estimate the lifetime costs and outcomes associated with HZ, PHN and other HZ-related complications for vaccinated and non-vaccinated cohorts aged >or=60 years. Clinical trial data, published literature and other primary studies were used to inform the model. Robustness of results to key model parameters was explored through a series of one-way, multivariate and probabilistic sensitivity analyses. Both societal and payer perspectives were considered.

MAIN OUTCOME MEASURE

Incremental cost per quality-adjusted life year (QALY) gained.

RESULTS

For a representative cohort of 1,000,000 U.S. vaccine recipients aged >or=60 years, use of the zoster vaccine was projected to eliminate 75,548-88,928HZ cases and over 20,000 PHN cases. Over 300,000 outpatient visits, 375,000 prescriptions, 9,700 ER visits and 10,000 hospitalizations were projected to be eliminated with the vaccine translating into savings of US$ 82 million to US$ 103 million in healthcare costs associated with the diagnosis and treatment of HZ, PHN and other HZ-related complications. Cost-effectiveness ratios range from US$ 16,229 to US$ 27,609 per QALY gained, depending on the input data source and analytic perspective. Results were most sensitive to PHN costs, duration of vaccine efficacy, vaccine efficacy against PHN and HZ, QALY loss associated with pain states and complication costs.

CONCLUSIONS

The zoster vaccine at a price of US$ 150 is likely to be cost-effective for a cohort of immunocompetent U.S. vaccine recipients aged >or=60 years using commonly cited thresholds for judging cost-effectiveness. Conclusions are robust over plausible ranges of input parameter values and a broad range of scenarios and age cohorts.

Using focus groups to develop contingent valuation scenarios--a case study of women's groups in rural Nepal

The construction of a contingent valuation (CV) scenario forms a critical component of willingness-to-pay (WTP) survey design, especially when working across diverse cultural and socio-economic settings. However, the methods used to develop CV scenarios have not been well reported in the health economics literature. This paper begins by describing how qualitative methods can be used to develop CV surveys. It then presents a case study illustrating how focus groups were used to develop a CV survey to value a women's group intervention in rural Nepal. A series of focus group discussions were conducted with three stakeholder groups. These were used to determine the most appropriate description of the good to be valued and the means by which payment would be elicited. These methods were very helpful in designing the survey tool and choosing the key attributes to describe the intervention. They also familiarised field workers with the concept of WTP. Further work of this kind will help to highlight additional advantages and limitations of qualitative approaches to survey design.

Valuing avoided morbidity using meta-regression analysis: what can health status measures and QALYs tell us about WTP?

Many economists argue that willingness-to-pay (WTP) measures are most appropriate for assessing the welfare effects of health changes. Nevertheless, the health evaluation literature is still dominated by studies estimating nonmonetary health status measures (HSMs), which are often used to assess changes in quality-adjusted life years (QALYs). Using meta-regression analysis, this paper combines results from both WTP and HSM studies applied to acute morbidity, and it tests whether a systematic relationship exists between HSM and WTP estimates. We analyze over 230 WTP estimates from 17 different studies and find evidence that QALY-based estimates of illness severity--as measured by the Quality of Well-Being (QWB) Scale--are significant factors in explaining variation in WTP, as are changes in the duration of illness and the average income and age of the study populations. In addition, we test and reject the assumption of a constant WTP per QALY gain. We also demonstrate how the estimated meta-regression equations can serve as benefit transfer functions for policy analysis. By specifying the change in duration and severity of the acute illness and the characteristics of the affected population, we apply the regression functions to predict average WTP per case avoided.

Using preference-based measures to assess quality of life in stuttering

PURPOSE

The purpose of this study was to determine whether standard pharmaco-economic preference methods can be used to assess perceived quality of life in stuttering.

METHOD

Seventy-five nonstuttering adults completed a standardized face-to-face interview that included a rating scale, standard gamble, and time trade-off preference measures for 4 health states (your health and mild, moderate, and severe stuttering) in the context of 2 anchor states (perfect health and death).

RESULTS

Results showed mean utility values between .443 for severe stuttering estimated using the rating scale technique and .982 for respondents' own current health estimated using a standard gamble technique. A two-way repeated measures analysis of variance and post hoc tests showed significant effects for method, health state, and the interaction.

CONCLUSIONS

These results confirm that utility estimates can differentiate between stuttering severity levels and that utility scores for stuttering conform to the known properties of data obtained using these standard measurement techniques. These techniques, therefore, can and should be further investigated as potential contributors to complete measurement protocols for the study and treatment of stuttering.

Overcoming inherent problems of preference-based techniques for measuring health benefits: an empirical study in the context of kidney transplantation

Background

Economic valuations of health care programs often require using patients as subjects, implying that research methodology should conform to the surrounding social, cultural and ethical context. The significance of patients' opinions in health care decisions has been well defined but in Greece, and perhaps elsewhere, clinicians remain skeptical. The purpose of this study was to investigate, for the first time in Greece, the feasibility of measuring preference-based health-state utilities and willingness to pay and to determine the context-based adaptations required to overcome inherent elicitation problems.

Methods

A survey including a time trade-off (TTO), a standard gamble (SG), and two willingness-to-pay (WTP) questions was self-administered to a homogenous group of 606 end stage renal disease patients in 24 dialysis facilities throughout Greece and the overall response rate was 78.5%. Typical elicitation methods were adapted to overcome methodological problems such as subjective life expectancy and question framing. Spearman's correlation coefficients were calculated between utilities and WTP and parametric tests (independent samples t-test and ANOVA) examined score differences as a result of demographic and clinical factors.

Results

Mean health-state utilities were 72.56 (TTO) and 91.06 (SG) and these were statistically significantly different (P < 0.0005). Significant correlations, in the expected directions, were observed between TTO – SG, TTO – WTP and SG – WTP (P < 0.01). High ceiling effects were observed in the TTO and SG methods indicating patients' adversity to risk and unwillingness to trade-off life years. Higher WTP was observed from younger patients (P < 0.0005), males (P < 0.05), higher education levels (P < 0.01), single (P < 0.0005) and employed (P < 0.005).

Conclusion

This study demonstrated, to a fair extent, that adapting research methods to context-based particularities does not necessarily compromise results and should be considered in situations where standard methods cannot be applied. On the other hand, it is emphasized that the results from this study are preliminary and should be interpreted cautiously until further research demonstrates the practicality, reliability and validity of alternative measurement approaches.

QALYs: are they helpful to decision makers?

The QALY is the product of life expectancy (estimated in years) and its quality over that time (estimated in utilities or QOL units). It theoretically enables direct comparison of the costs of obtaining different health outcomes through cost utility analysis (CUA). In this review, we argue that, at present, the problems related to the use of utilities preclude the use of cost per QALY as a major determinant of policy decisions on the acquisition and use of health technologies. Those who use CUA can be divided into (i) those who inform the process of decision making through CUA and (ii) those who make the decisions. The former have no direct budgetary responsibility for the decisions that are taken, while the decision makers must pay for those decisions from their budgets. Use of CUA rests on the assumption that all QALYs are of equivalent value in the eyes of society. However, the value accorded to them varies with circumstances. The utilities or QOL indices required to compute QALYs can be measured in different ways, which give different answers, and have been shown to be unreliable. Thus, the QALY is not sufficiently accurate or reliable to be used by decision makers as a basis for comparison of the costs of different technologies. Until the theoretical and practical problems of determining health preferences are resolved and the methods of their measurement are standardised, it is necessary to estimate the cost effectiveness of health interventions by relating their cost to their primary health outcomes.