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

A systematic review on the direct approach to elicit the demand-side cost-effectiveness threshold: Implications for low- and middle-income countries

Several literature review studies have been conducted on cost-effectiveness threshold values. However, only a few are systematic literature reviews, and most did not investigate the different methods, especially in-depth reviews of directly eliciting WTP per QALY. Our study aimed to 1) describe the different direct approach methods to elicit WTP/QALY; 2) investigate factors that contribute the most to the level of WTP/QALY value; and 3) investigate the relation between the value of WTP/QALY and GDP per capita and give some recommendations on feasible methods for eliciting WTP/QALY in low- and middle-income countries (LMICs). A systematic review concerning select studies estimating WTP/QALY from a direct approach was carried out in seven databases, with a cut off date of 03/2022. The conversion of monetary values into 2021 international dollars (i$) was performed via CPI and PPP indexes. The influential factors were evaluated with Bayesian model averaging. Criteria for recommendation for feasible methods in LMICs are made based on empirical evidence from the systematic review and given the resource limitation in LMICs. A total of 12,196 records were identified; 64 articles were included for full-text review. The WTP/QALY method and values varied widely across countries with a median WTP/QALY value of i$16,647.6 and WTP/QALY per GDP per capita of 0.53. A total of 11 factors were most influential, in which the discrete-choice experiment method had a posterior probability of 100%. Methods for deriving WTP/QALY vary largely across studies. Eleven influential factors contribute most to the level of values of WTP/QALY, in which the discrete-choice experiment method was the greatest affected. We also found that in most countries, values for WTP/QALY were below 1 x GDP per capita. Some important principles are addressed related to what LMICs may be concerned with when conducting studies to estimate WTP/QALY.

VOLY: The Monetary Value of a Life-Year at the End of Patients' Lives

OBJECTIVE

We explored the monetary value of the end-of-life (EoL) health gains, that is, the value of a life-year (VOLY) gained at the end of a patient's life in Croatia. We tested whether the nature of the illness under valuation (cancer and/or rare disease) is a factor in the valuation of EoL-VOLYs. The aim was for our results to contribute to the health and longevity valuation literature and more particularly to the debate on the appropriate cost-effectiveness threshold for EoL treatments as well as to provide input into the debate on the justifiability of a cancer and/or a rare disease premium when evaluating therapies.

METHODS

A contingent valuation was conducted in an online survey using a representative sample of the Croatian population (n = 1500) to calculate the willingness to pay for gains in the remaining life expectancy at the EoL, from the social-inclusive-individual perspective, using payment scales and an open-ended payment vehicle. Our approach mimics the actual decision-making problem of deciding whether to reimburse therapies targeting EoL conditions such as metastatic cancer whose main purpose is to extend life (and not add quality to life).

RESULTS

Average EoL-VOLY across all scenarios was estimated at €67,000 (median €40,000). In scenarios that offered respondents 1 full year of life extension, EoL-VOLY was estimated at €33,000 (median €22,000). Our results show that the type of illness is irrelevant for EoL-VOLY evaluations.

CONCLUSIONS

The pressure to reimburse expensive therapies targeting EoL conditions will continue to increase. Delivering "value for money" in healthcare, both in countries with relatively higher and lower budget restrictions, requires the valuation of different types of health gains, which should, in turn, affect our ability to evaluate their cost effectiveness.

Optimization Based Modeling for the Food Supply Chain's Resilience to Outbreaks

Scant research focuses on the resiliency of food supply chain networks to outbreaks, despite the estimated 600 million global foodborne illnesses annually. Outbreaks that cross country, state and provincial lines are virulent due to the number of people they can affect and difficulty controlling them. Research is needed on food supply chain networks, which are not well-characterized in relation to foodborne illnesses or generally. This paper introduces the United States Food, Energy, and State Transportation (US-FEAST) model and demonstrates its applicability via analysis of a hypothetical demand shock resulting from multistate food contamination. US-FEAST is an optimization-based model across all fifty states with yearly timesteps to 2030. It is a framework integrating food system data from multiple individual data sources. To calibrate, we develop a bilevel optimization routine to generate synthetic, state-level data and provide estimates of otherwise unavailable data at the intersections of the food and transportation systems. The results of US-FEAST elucidate potential heterogenous state-level variations in response, regional changes in food flows, vulnerabilities in the supply chain, and implications for food system resilience. While the generated data and scenarios are not empirical evidence, they provide insights to aid in planning by projecting outcomes and intervention effects. Our results estimate a 23% beef production decrease and 4% price decrease provide a road map toward data needs for quantifying food system resilience to foodborne illness. US-FEAST and its framework may have global utility for studying food safety in national and international food supply chain networks.

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.

How Much Is a Human Life Worth? A Systematic Review

OBJECTIVES

To systematically review studies eliciting monetary value of a statistical life (VSL) estimates within, and across, different sectors and other contexts; compare the reported estimates; and critically review the elicitation methods used.

METHODS

In June 2019, we searched the following databases to identify methodological and empirical studies: Cochrane Library, Compendex, Embase, Environment Complete, Informit, ProQuest, PubMed, Scopus, and Web of Science. We used the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines for reporting and a modified Consolidated Health Economic Evaluation Reporting Standards checklist to assess the quality of included studies.

RESULTS

We identified 1455 studies, of which we included 120 in the systematic review. A stated-preference approach was used in 76 articles, with 51%, 41%, and 8% being contingent valuation studies, discrete-choice experiments, or both, respectively. A revealed-preference approach was used in 43 articles, of which 74% were based on compensating-wage differentials. The human capital approach was used in only 1 article. We assessed most publications (87%) as being of high quality. Estimates for VSL varied substantially by context (sector, developed/developing country, socio-economic status, etc), with the median of midpoint purchasing power parity-adjusted estimates of 2019 US$5.7 million ($6.8 million, $8.7 million, and $5.3 million for health, labor market, and transportation safety sectors, respectively).

CONCLUSIONS

The large variation observed in published VSLs depends mainly on the context rather than the method used. We found higher median values for labor markets and developed countries. It is important that health economists and policymakers use context-specific VSL estimates. Methodological innovation and standardization are needed to maximize comparability of VSL estimates within, and across, sectors and methods.

A Systematic Review of Demand-Side Methods of Estimating the Societal Monetary Value of Health Gain

OBJECTIVES

Although many reviews of the literature on cost-effectiveness thresholds (CETs) exist, the availability of new studies and the absence of a fully comprehensive analysis warrant a new review. This study systematically reviews demand-side methods for estimating the societal monetary value of health gain.

METHODS

Several electronic databases were searched from inception to October 2019. To be included, a study had to be an original article in any language, with a clearly described method for estimating the societal monetary values of health gain and with all estimated values reported. Estimates were converted to US dollars ($), using purchasing power parity (PPP) exchange rates and the gross domestic product (GDP) per capita (2019).

RESULTS

We included 53 studies; 45 used direct approach and 8 used indirect approach. Median estimates from the direct approach were PPP$ 24 942 (range 554-1 301 912) per quality-adjusted life-year (QALY), which were typically 0.53 (range 0.02-24.08) GDP per capita. Median estimates using the indirect approach were PPP$ 310 051 (range 36 402-7 574 870) per QALY, which accounted for 7.87 (range 0.68-116.95) GDP per capita.

CONCLUSIONS

Our review found that the societal values of health gain or CETs were less than GDP per capita. The great variety in methods and estimates suggests that a more standardized and internationally agreed methodology for estimating CET is warranted. Multiple CETs may have a role when QALYs are not equally valued from a societal perspective (eg, QALYs accruing to people near death compared with equivalent QALYs to others).

Valuation of Local Demand for Improved Air Quality: The Case of the Mae Moh Coal Mine Site in Thailand

While the district of Mae Moh, Thailand has been well known for its atmospheric pollution associated with coal power production, economic assessment of demand for improved air quality has not been conducted to date. This study estimated local residents’ individual and aggregate willingness to pay (WTP) for mitigation of atmospheric pollution in Mae Moh using the contingent valuation method (CVM), and analyzed the factors associated with the individual WTP using the bivariate tobit and double-hurdle regression techniques. Primary data were collected through face-to-face interviews with a stratified sample of 200 residents. The hypothetical scenarios used in the CVM module were 50% and 80% mitigation of atmospheric concentrations of major pollutants. The weighted average WTP was found to be THB 251.3 and 307.9 per annum (USD 8.4 and 10.3) for the 50% and 80% reduction scenarios, respectively. The aggregate WTP for the entire population of Mae Moh was THB 10,008,733 and 12,264,761 per annum (USD 336,294 and 412,096), respectively. Education, occupation type, income, expenses, satisfaction with ambient quality, and perceived sources of pollution had significant associations with the individual WTP. The paper concludes by discussing policy implications for atmospheric pollution management and avenues for future research.

Transition in air pollution, disease burden and health cost in China: A comparative study of long-term and short-term exposure

Ambient air pollution is one of the leading environmental risk factors to human health, largely offsetting economic growth. This study evaluated health burden and cost associated with the short-term and long-term exposure of major air pollutants (fine particulate matter [PM_2.5] and ozone [O₃]) during 2013-2018. We developed a database of gridded daily and annual PM_2.5 and O₃ exposure in China at 15 km × 15 km resolution. Then, we estimated the age- and cause-specific premature deaths and quantified related health damage with an age-adjusted value of statistical life (VSL) measure. The health cost estimated in this study captured direct cost, indirect cost and intangible cost of the premature death attributable to ambient PM_2.5 and O₃. We found that the national premature deaths attributable to long-term and short-term exposure to PM_2.5 decreased by 15% and 59%, whereas the national premature deaths attributable to long-term and short-term exposure to O₃ increased by 36% and 94%. Despite a 15% reduction of attributable deaths, the health cost attributable to long-term exposure to PM_2.5 did not change significantly as a result of GDP growth and population aging. On the other hand, the long-term O₃ related health cost in 2018 doubled that in 2013. Our study suggests that while premature deaths fell as a result of China's clean air actions, the health costs of air pollution remained high. The growing trends of O₃ highlighted the needs for strategies to reduce both PM_2.5 and O₃ emissions, for the sake of public health and social well-being in China.

Risk Analysis: Celebrating the Accomplishments and Embracing Ongoing Challenges

As part of the celebration of the 40th anniversary of the Society for Risk Analysis and Risk Analysis: An International Journal, this essay reviews the 10 most important accomplishments of risk analysis from 1980 to 2010, outlines major accomplishments in three major categories from 2011 to 2019, discusses how editors circulate authors' accomplishments, and proposes 10 major risk-related challenges for 2020-2030. Authors conclude that the next decade will severely test the field of risk analysis.

Theoretical bounds on the value of improved health

Policies that improve health and longevity are often valued by combining expected gains in quality-adjusted life years (QALYs) with a constant willingness-to-pay (WTP) per QALY. This constant is derived by dividing value per statistical life (VSL) estimates by expected future QALYs. We explore the theoretical validity of this practice by studying the properties of WTP for improved health and longevity in a framework that makes minimal assumptions about the shape of an agent's utility function. We find that dividing VSL by expected QALYs results in an upper bound on the WTP for a marginal improvement in the quality of life, as measured by gains in health status or longevity. Calibration results suggest that analysts using this approach to monetize health benefits overestimate the value of a program or policy by a factor of two on average. We also derive a lower bound on the WTP for improved health and longevity that permits a novel empirical test for the descriptive validity of the QALY model. Our calibrations suggest that this lower bound is on average 20% smaller than the actual WTP.

The societal monetary value of a QALY associated with EQ-5D-3L health gains

There is an extensive body of empirical research that focuses on the societal monetary value of a quality-adjusted life year (MVQALY). Many of these studies have found the estimates to be inversely associated with the size of the health gain, and thus not conforming to the linearity assumption imposed in the QALY model. In this study, we explore the extent to which the MVQALY varies when it is associated with different types and magnitudes of quality of life (QoL) improvements. To allow for a comprehensive assessment, we derive the MVQALY corresponding to the full spectrum of health gains defined by the EQ-5D-3L instrument. The analysis was based on a large and representative sample of the population in Spain. A discrete choice experiment and a time trade-off exercise were used to derive a value set for utilities, followed by a willingness to pay questionnaire. The data were jointly analysed using regression analyses and bootstrapping techniques. Our findings indicate that societal values for a QALY corresponding to different EQ-5D-3L health gains vary approximately between 10,000€ and 30,000€. MVQALY associated with larger improvements on QoL was found to be lower than that associated with moderate QoL gains. The potential sources of the observed non-constant MVQALY are discussed.

Understanding the global measurement of willingness to pay in health

Objective: To understand the different methodologies used to elicit willingness to pay for health and the value of a statistical life year through surveys. Methodology: A systematic review of the literature was undertaken to identify studies using surveys to estimate either willingness to pay for health or the value of a statistical life year. Each study was reviewed and the study setting, sample size, sample description, survey administration (online or face to face), survey methodology, and results were extracted. The results of the studies were then compared to any published national guidelines of cost-effectiveness thresholds to determine their accuracy. Results: Eighteen studies were included in the review with 15 classified as willingness to pay and 3 value of a statistical life. The included studies covered Asia (n = 6), Europe (n = 4), the Middle East (n = 1), and North America (n = 5), with one study taking a global perspective. There were substantial differences in both the methodologies and the estimates of both willingness to pay and value of a statistical life between the different studies. Conclusion: Different methods used to elicit willingness to pay and the value of a statistical life year resulted in a wide range of estimates.

Differential discounting in the economic evaluation of healthcare programs

Background

The question of appropriate discount rates in health economic evaluations has been a point of continuous scientific debate. Today, it is widely accepted that, under certain conditions regarding the social objective of the healthcare decision maker and the fixity of the budget for healthcare, a lower discount rate for health gains than for costs is justified if the consumption value of health is increasing over time. To date, however, there is neither empirical evidence nor a strong theoretical a priori supporting this assumption. Given this lack of evidence, we offer an additional approach to check the appropriateness of differential discounting.

Methods

Our approach is based on a two-goods extension of Ramsey's optimal growth model which allows accounting for changing relative values of goods explicitly. Assuming a constant elasticity of substitution (CES) utility function, the growth rate of the consumption value of health depends on three variables: the growth rate of consumption, the growth rate of health, and the income elasticity of the willingness to pay for health. Based on a review of the empirical literature on the monetary value of health, we apply the approach to obtain an empirical value of the growth rate of the consumption value of health in Germany.

Results

The empirical literature suggests that the income elasticity of the willingness to pay for health is probably not larger but rather smaller than 1 and probably not smaller but rather larger than 0.2. Combining this finding with reasonable values of the annual growth rates in consumption (1.5-1.6%) and health (0.1%) suggests, for Germany, an annual growth rate of the consumption value of health between 0.3 and 1.5%.

Conclusion

In the light of a two-goods extension of Ramsey's optimal growth model, the available empirical evidence makes the case for a growing consumption value of health. Therefore, the current German practice of applying the same discount rate to costs and health gains introduces a systematic bias against healthcare technologies with upfront costs and long-term health effects. Differential discounting with a lower rate for health effects appears to be a more appropriate discounting model.

Critical review of methods for risk ranking of food-related hazards, based on risks for human health

This study aimed to critically review methods for ranking risks related to food safety and dietary hazards on the basis of their anticipated human health impacts. A literature review was performed to identify and characterize methods for risk ranking from the fields of food, environmental science and socio-economic sciences. The review used a predefined search protocol, and covered the bibliographic databases Scopus, CAB Abstracts, Web of Sciences, and PubMed over the period 1993-2013. All references deemed relevant, on the basis of predefined evaluation criteria, were included in the review, and the risk ranking method characterized. The methods were then clustered-based on their characteristics-into eleven method categories. These categories included: risk assessment, comparative risk assessment, risk ratio method, scoring method, cost of illness, health adjusted life years (HALY), multi-criteria decision analysis, risk matrix, flow charts/decision trees, stated preference techniques and expert synthesis. Method categories were described by their characteristics, weaknesses and strengths, data resources, and fields of applications. It was concluded there is no single best method for risk ranking. The method to be used should be selected on the basis of risk manager/assessor requirements, data availability, and the characteristics of the method. Recommendations for future use and application are provided.

What Drives Responses to Willingness-to-pay Questions? A Methodological Inquiry in the Context of Hypertension Self-management

Background: The use of economic evaluation to determine the cost-effectiveness of health interventions is recommended by decision-making bodies internationally. Understanding factors that explain variations in costs and benefits is important for policy makers. Objective: This work aimed to test a priori hypotheses defining the relationship between benefits of using self-management equipment (measured using the willingness-to-pay (WTP) approach) and a number of demographic and other patient factors. Methods: Data for this study were collected as part of the first major randomised controlled trial of self-monitoring combined with self-titration in hypertension (TASMINH2). A contingent valuation framework was used with patients asked to indicate how much they were willing to pay for equipment used for self-managing hypertension. Descriptive statistics, simple statistical tests of differences and multivariate regression were used to test six a priori hypotheses. Results: 393 hypertensive patients (204 in the intervention and 189 in the control) were willing to pay for self-management equipment and 85% of these (335) provided positive WTP values. Three hypotheses were accepted: higher WTP values were associated with being male, higher household incomes and satisfaction with the equipment. Prior experiences of using this equipment, age and changes in blood pressure were not significantly related to WTP. Conclusion: The majority of hypertensive patients who had taken part in a self-management study were prepared to purchase the self-monitoring equipment using their own funds, more so for men, those with higher incomes and those with greater satisfaction. Further research based on bigger and more diverse populations is recommended.

On the Estimation of the Cost-Effectiveness Threshold: Why, What, How?

BACKGROUND

Many health care systems claim to incorporate the cost-effectiveness criterion in their investment decisions. Information on the system's willingness to pay per effectiveness unit, normally measured as quality-adjusted life-years (QALYs), however, is not available in most countries. This is partly because of the controversy that remains around the use of a cost-effectiveness threshold, about what the threshold ought to represent, and about the appropriate methodology to arrive at a threshold value.

OBJECTIVES

The aim of this article was to identify and critically appraise the conceptual perspectives and methodologies used to date to estimate the cost-effectiveness threshold.

METHODS

We provided an in-depth discussion of different conceptual views and undertook a systematic review of empirical analyses. Identified studies were categorized into the two main conceptual perspectives that argue that the threshold should reflect 1) the value that society places on a QALY and 2) the opportunity cost of investment to the system given budget constraints.

RESULTS

These studies showed different underpinning assumptions, strengths, and limitations, which are highlighted and discussed. Furthermore, this review allowed us to compare the cost-effectiveness threshold estimates derived from different types of studies. We found that thresholds based on society's valuation of a QALY are generally larger than thresholds resulting from estimating the opportunity cost to the health care system.

CONCLUSIONS

This implies that some interventions with positive social net benefits, as informed by individuals' preferences, might not be an appropriate use of resources under fixed budget constraints.

The Willingness to Pay for a Quality Adjusted Life Year: A Review of the Empirical Literature

There has been a rapid increase in the use of cost-effectiveness analysis, with quality adjusted life years (QALYs) as an outcome measure, in evaluating both medical technologies and public health interventions. Alongside, there is a growing literature on the monetary value of a QALY based on estimates of the willingness to pay (WTP). This paper conducts a review of the literature on the WTP for a QALY. In total, 24 studies containing 383 unique estimates of the WTP for a QALY are identified. Trimmed mean and median estimates amount to 74,159 and 24,226 Euros (2010 price level), respectively. In regression analyses, the results indicate that the WTP for a QALY is significantly higher if the QALY gain comes from life extension rather than quality of life improvements. The results also show that the WTP for a QALY is dependent on the size of the QALY gain valued. Copyright © 2014 John Wiley & Sons, Ltd.

Assessing Air Pollutant-Induced, Health-Related External Costs in the Context of Nonmarginal System Changes: A Review

Marginal analysis is the usual approach to environmental economic assessment, for instance, of health-related external costs due to energy-associated air pollutant emissions. However, nonlinearity exists in all steps of their assessment, i.e., atmospheric dispersion, impact assessment, and monetary valuation. Dedicated assessments thus appear necessary when evaluating large systems or their changes such as in green accounting or the implications of economy-wide energy transitions. Corresponding approaches are reviewed. Tools already exist that allow assessing a marginal change (e.g., one power plant's emissions) for different background emission scenarios that merely need to be defined and implemented. When assessing nonmarginal changes, the top-down approach is considered obsolete, and four variants of the bottom-up approach with different application domains were identified. Variants 1 and 2 use precalculated external cost factors with different levels of sophistication, suitable for energy systems modeling, optimizing for social (i.e., private and external) costs. Providing more reliable results due to more detailed modeling, emission sources are assessed individually or jointly in variants 3 and 4, respectively. Aiming at considering nonlinearity more fully and simultaneously following marginal analysis principles, I propose a variant 3-based approach, subdividing an aggregate (i.e., a nonmarginal change) into several smaller changes. Its strengths and drawbacks, notably the associated effort, are discussed.

An ethical framework for responding to drug shortages in pediatric oncology

The frequency of drug shortages has increased considerably over the last decade. Important ethical issues arise whenever the supply of an effective drug is insufficient to meet demand. Using the ethical principles of beneficence, non-maleficence, and justice, institutions can guide prioritization of drug distribution before a shortage occurs to avoid unfair and unethical distribution of resources. This analysis will give a historical context for drug shortages, identify, and explore the central ethical concerns raised by drug shortages, and propose an ethical framework for addressing them in the context of pediatric oncology.

The Per Case and Total Annual Costs of Foodborne Illness in the United States

We present an economic welfare-based method to estimate the health costs associated with foodborne illness caused by known viruses, bacteria, parasites, allergens, two marine biotoxins, and unspecified agents. The method generates health costs measured in both quality-adjusted life years and in dollars. We calculate the reduction in quality-adjusted life days caused by the illness and add reductions in quality-adjusted life years from any secondary effects that are estimated to occur. For fatal cases, we calculate the life years lost due to premature death. We add direct medical expenses to the monetary costs as derived from estimates of willingness to pay to reduce health risks. In total, we estimate that foodborne illness represents an annual burden to society of approximately $36 billion, with an average identified illness estimated to reduce quality-adjusted life days by 0.84, which is monetized and included in the average cost burden per illness of $3,630.

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.

Comparing WTP values of different types of QALY gain elicited from the general public

BACKGROUND

The appropriate thresholds for decisions on the cost-effectiveness of medical interventions remain controversial, especially in 'end-of-life' situations. Evidence of the values placed on different types of health gain by the general public is limited.

METHODS

Across nine European countries, 17,657 people were presented with different hypothetical health scenarios each involving a gain of one quality adjusted life year (QALY) and asked about their willingness to pay (WTP) for that gain. The questions included quality of life (QoL) enhancing and life extending health gains, and a scenario where respondents faced imminent, premature death.

RESULTS

The mean WTP values for a one-QALY gain composed of QoL improvements were modest (PPP$11,000). When comparing QALY gains obtained in the near future, the valuation of life extension exceeded the valuation of QoL enhancing gains (mean WTP PPP$19,000 for a scenario in which a coma is avoided). The mean WTP values were higher still when respondents faced imminent, premature death (PPP$29,000).

CONCLUSIONS

Evidence from the largest survey on the value of health gains by the general public indicated a higher value for life extending gains compared with QoL enhancing gains. A further modest premium may be indicated for life extension when facing imminent, premature death.

Willingness to pay for a quality-adjusted life year: an evaluation of attitudes towards risk and preferences

Background

This paper examines the Willingness to Pay (WTP) for a quality-adjusted life year (QALY) expressed by people who attended the healthcare system as well as the association of attitude towards risk and other personal characteristics with their response.

Methods

Health-state preferences, measured by EuroQol (EQ-5D-3L), were combined with WTP for recovering a perfect health state. WTP was assessed using close-ended, iterative bidding, contingent valuation method. Data on demographic and socioeconomic characteristics, as well as usage of health services by the subjects were collected. The attitude towards risk was evaluated by collecting risky behaviors data, by the subject’s self-evaluation, and through lottery games.

Results

Six hundred and sixty two subjects participated and 449 stated a utility inferior to 1. WTP/QALY ratios varied significantly when payments with personal money (mean €10,119; median €673) or through taxes (mean €28,187; median €915) were suggested. Family income, area income, higher education level, greater use of healthcare services, and the number of co-inhabitants were associated with greater WTP/QALY ratios. Age and female gender were associated with lower WTP/QALY ratios. Risk inclination was independently associated with a greater WTP/QALY when “out of pocket” payments were suggested. Clear discrepancies were demonstrated between linearity and neutrality towards risk assumptions and experimental results.

Conclusions

WTP/QALY ratios vary noticeably based on demographic and socioeconomic characteristics of the subject, but also on their attitude towards risk. Knowing the expression of preferences by patients from this outcome measurement can be of interest for health service planning.

Annual cost of illness and quality-adjusted life year losses in the United States due to 14 foodborne pathogens

In this article we estimate the annual cost of illness and quality-adjusted life year (QALY) loss in the United States caused by 14 of the 31 major foodborne pathogens reported on by Scallan et al. (Emerg. Infect. Dis. 17:7-15, 2011), based on their incidence estimates of foodborne illness in the United States. These 14 pathogens account for 95 % of illnesses and hospitalizations and 98 % of deaths due to identifiable pathogens estimated by Scallan et al. We estimate that these 14 pathogens cause $14.0 billion (ranging from $4.4 billion to $33.0 billion) in cost of illness and a loss of 61,000 QALYs (ranging from 19,000 to 145,000 QALYs) per year. Roughly 90 % of this loss is caused by five pathogens: nontyphoidal Salmonella enterica ($3.3 billion; 17,000 QALYs), Campylobacter spp. ($1.7 billion; 13,300 QALYs), Listeria monocytogenes ($2.6 billion; 9,400 QALYs), Toxoplasma gondii ($3 billion; 11,000 QALYs), and norovirus ($2 billion; 5,000 QALYs). A companion article attributes losses estimated in this study to the consumption of specific categories of foods. To arrive at these estimates, for each pathogen we create disease outcome trees that characterize the symptoms, severities, durations, outcomes, and likelihoods of health states associated with that pathogen. We then estimate the cost of illness (medical costs, productivity loss, and valuation of premature mortality) for each pathogen. We also estimate QALY loss for each health state associated with a given pathogen, using the EuroQol 5D scale. Construction of disease outcome trees, outcome-specific cost of illness, and EuroQol 5D scoring are described in greater detail in a second companion article.