Testing Nonmonotonicity in Health Preferences.

OBJECTIVE: The main aim of this article is to test monotonicity in life duration. Previous findings suggest that, for poor health states, longer durations are preferred to shorter durations up to some threshold or maximum endurable time (MET), and shorter durations are preferred to longer ones after that threshold. METHODS: Monotonicity in duration is tested through 2 ordinal tasks: choices and rankings. A convenience sample (n = 90) was recruited in a series of experimental sessions in which participants had to rank-order health episodes and to choose between them, presented in pairs. Health episodes result from the combination of 7 EQ-5D-3L health states and 5 durations. Monotonicity is tested comparing the percentage rate of participants whose preferences were monotonic with the percentage of participants with nonmonotonic preferences for each health state. In addition, to test the existence of preference reversals, we analyze the fraction of people who switch their preference from rankings to choices. RESULTS: Monotonicity is frequently violated across the 7 EQ-5D health states. Preference patterns for individuals describe violations ranging from almost 49% with choices to about 71% with rankings. Analysis performed by separate states shows that the mean rates of violations with choices and ranking are about 22% and 34%, respectively. We also find new evidence of preference reversals and some evidence-though scarce-of transitivity violations in choices. CONCLUSIONS: Our results show that there is a medium range of health states for which preferences are nonmonotonic. These findings support previous evidence on MET preferences and introduce a new "choice-ranking" preference reversal. It seems that the use of 2 tasks with a similar response scale may make preference reversals less substantial, although it remains important and systematic. HIGHLIGHTS: Two procedures based on ordinal comparisons are used to elicit preferences: direct choices and rankings. Our study reports significant rates of nonmonotonic preferences (or maximum endurable time [MET]-type preferences) for different combinations of durations and EQ-5D health states.Analysis for separate health states shows that the mean rates of nonmonotonicity range from 22% (choices) to 34% (rankings), but within-subject analysis shows that nonmonotonicity is even higher, ranging from 49% (choices) to 71% (rankings). These violations challenge the validity of multiplicative QALY models.We find that the MET phenomenon may affect particularly those EQ-5D health states that are in the middle of the severity scale and not so much the extreme health states (i.e., very mild and very severe states).We find new evidence of preference reversals even using 2 procedures of a similar (ordinal) nature. Percentage rates of preference reversals range from 1.5% to 33%. We also find some (although scarce) evidence on violations of transitivity.

Reference-dependent age weighting of quality-adjusted life years.

People do not only care about maximizing health gains but also about their distribution. For example, they give more weight to younger patients than older patients. This pilot study aims to investigate if age weighting is reinforced by loss aversion if young people are falling behind one's perceived 'normal' quality of life (QoL), while older people do not. We apply a person trade-off method in a large representative sample (n = 990) to estimate age weighting factors. We also measure QoL levels that individuals regard as 'normal' for different ages, serving as reference points. We observe a considerable amount of age weighting, with 20-year-old patients on average receiving 1.7 times as much weight as 80-year-old patients. Perceived 'normal' QoL rapidly decreases with age of a patient. Older people are more optimistic about what constitutes 'normal QoL' than younger people, but they express a faster decline in normal QoL due to aging. Respondents who view all improvements to be gain enlarging show the least age weighting, but loss aversion cannot explain the results. Still, one's age-related reference level is an important predictor of age weights. Given the explorative nature of this study, further studies are called for to generate more robust evidence.

¿Qué es una intervención sanitaria eficiente en España en 2020? / What is an efficient health intervention in Spain in 2020?

Hace más de 15 años que en Gaceta Sanitaria se publicó el artículo titulado «¿Qué es una tecnología sanitaria eficiente en España?». El creciente interés por fijar el precio de las nuevas tecnologías en función del valor que estas proporcionan a los sistemas de salud y la experiencia acumulada por los países de nuestro entorno hacen oportuno revisar qué es una intervención sanitaria eficiente en España en el año 2020. El análisis de coste-efectividad sigue siendo el método de referencia para maximizar los resultados en salud de la sociedad con los recursos disponibles. La interpretación de sus resultados requiere establecer unos valores de referencia que sirvan de guía sobre lo que constituye un valor razonable para el sistema sanitario. Los umbrales de eficiencia deben ser flexibles y dinámicos, y actualizarse periódicamente. Su aplicación debe estar basada en la gradualidad y la transparencia, considerando, además, otros factores que reflejen las preferencias sociales. Aunque la fijación de los umbrales corresponde a los decisores políticos, en España puede ser razonable utilizar unos valores de referencia como punto de partida que podrían estar comprendidos entre los 25.000 y los 60.000 euros por año de vida ajustado por calidad. No obstante, en la actualidad, más que la determinación de las cifras exactas de dicho umbral, la cuestión clave es si el Sistema Nacional de Salud está preparado y dispuesto a implantar un modelo de pago basado en el valor, que contribuya a lograr la gradualidad en las decisiones de financiación y, sobre todo, a mejorar la previsibilidad, la consistencia y la transparencia del proceso

Fifteen years ago, Gaceta Sanitaria published the article entitled "What is an efficient health technology in Spain?" The growing interest in setting the price of new technologies based on the value they provide to health systems and the experience accumulated by the countries in our environment make it opportune to review what constitutes an efficient health intervention in Spain in 2020. Cost-effectiveness analysis continues to be the reference method to maximize social health outcomes with the available resources. The interpretation of its results requires establishing reference values that serve as a guide on what constitutes a reasonable value for the health care system. Efficiency thresholds must be flexible and dynamic, and they need to be updated periodically. Its application should be based on and transparency, and consider other factors that reflect social preferences. Although setting thresholds is down to political decision-makers, in Spain it could be reasonable to use thresholds of 25,000 and 60,000 Euros per QALY. However, currently, in addition to determining exact figures for the threshold, the key question is whether the Spanish National Health System is able and willing to implement a payment model based on value, towards achieving gradual financing decisions and, above all, to improve the predictability, consistency and transparency of the process

[What is an efficient health intervention in Spain in 2020?] / ¿Qué es una intervención sanitaria eficiente en España en 2020?

Fifteen years ago, Gaceta Sanitaria published the article entitled "What is an efficient health technology in Spain?" The growing interest in setting the price of new technologies based on the value they provide to health systems and the experience accumulated by the countries in our environment make it opportune to review what constitutes an efficient health intervention in Spain in 2020. Cost-effectiveness analysis continues to be the reference method to maximize social health outcomes with the available resources. The interpretation of its results requires establishing reference values that serve as a guide on what constitutes a reasonable value for the health care system. Efficiency thresholds must be flexible and dynamic, and they need to be updated periodically. Its application should be based on and transparency, and consider other factors that reflect social preferences. Although setting thresholds is down to political decision-makers, in Spain it could be reasonable to use thresholds of 25,000 and 60,000 Euros per QALY. However, currently, in addition to determining exact figures for the threshold, the key question is whether the Spanish National Health System is able and willing to implement a payment model based on value, towards achieving gradual financing decisions and, above all, to improve the predictability, consistency and transparency of the process.

Exploring the relative value of end of life QALYs: Are the comparators important?

In the UK, life extending, end-of-life (EoL) treatments are an exception to standard cost-per-quality-adjusted life year (QALY) thresholds. This implies that greater value is placed on gaining these QALYs, than QALYs gained by the majority of other patient groups treated for anything else in the health system, even for other EoL contexts (such as quality of life (QoL) improvements alone). This paper reports a Person Trade-Off (PTO) study to test whether studies that find societal support for prioritising EoL life extensions can be explained by the severity, in terms of prospective QALYs loss, of the non-terminal comparator scenarios. Eight health scenarios were designed depicting i) QoL improvements for non-EoL temporary (T-QoL) and chronic (C-QoL) health problems and ii) QoL improvements and life extensions (LEs) for EoL health problems. Preferences were elicited from a quota sample of 901 Scottish respondents in 2016 using PTO techniques via Computer Assisted Personal Interview (CAPI). Our results indicate that there is little evidence to suggest that the severity of non-EoL comparator scenarios influence preferences for EoL treatments. Respondents do not appear to have a preference for EoL over non-EoL health gains; instead there is some indication that non-EoL health gains are preferred, particularly when compared to EoL-LE health gains. Comparing between QoL and life extending EoL scenarios, our results suggest QoL improvements are preferred to life extensions. Overall, results challenge current UK EoL policy which gives additional weight to EoL health gains, particularly EoL life extensions in the case of the National Institute for Health and Care Excellence (NICE).

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.

Sequence effects in time trade-off valuation of hypothetical health states.

Choice-based stated preference methods, such as time trade-offs (TTOs), are used to establish health state utilities informing healthcare allocation. However, little is known about the presence of (position-dependent and precedent-dependent) sequence effects in the valuation of health states, despite techniques requiring respondents to evaluate several health states in a sequence. This paper is the first to explicitly test for the presence of sequence effects in the health domain using a new explanation based on contrast effects and preference imprecision; the implication being that randomisation cannot avoid sequence effects. Six TTO questions were designed using the EQ-5D-3L descriptive system. These were grouped into two blocks of three and within each block four sequences were used. In an online survey, 1,197 Spanish respondents answered one grouping of three TTO questions. Results indicate that sequence effects can affect preferences as utilities of health states are biased downwards if preceded by a better health state and biased upwards if preceded by a worse health state. This study informs our understanding of how context effects interact with preference elicitation methods, which is essential for interpreting survey results used to inform policy.

Eliciting Health State Utilities Using Paired-Gamble Methods: The Role of the Starting Point.

BACKGROUND: Paired-gamble methods have been proposed to avoid the "certainty effect" associated with standard gamble methods. OBJECTIVE: This study examines the role of starting-point effects in paired-gamble methods. In particular, it examines how the utilities so derived vary as a function of the probabilities of the stimulus lottery. METHODS: A sample of 455 members of the Spanish general population valued 9 health states via face-to-face interviews. Subjects were randomly placed into 3 subgroups, which differed in terms of the stimulus gamble's probability. Nonparametric tests and an interval regression model were used to test if utilities change when the probability distribution is modified. RESULTS: Nonparametric tests showed that the probability of a health state being considered worse than death did not differ among subgroups. Nevertheless, changes in the stimulus gamble did produce significant differences in the distribution of utilities: the higher the probability of full health in the stimulus, the higher the utility elicited. Regression estimates support the existence of starting-point effects when the utilities are obtained under expected utility. According to the prospect theory, the conclusions depend on the reference point considered. When the reference points used are death or the health state evaluated, we observe differences among these groups. Nevertheless, when full health is used, these differences disappear. CONCLUSION: This research suggests that paired-gamble methods may also be susceptible to starting-point effects. Yet the differences are small, and they disappear when the data are analyzed using prospect theory with full health as the reference point.

Do time trade-off values fully capture attitudes that are relevant to health-related choices?

Previous research has shown that demographics, beliefs, and self-reported own health influence TTO values. Our hypothesis is that attitudes towards length and quality of life influence TTO values, but should no longer affect a set of related choices that are based on respondents' own TTO scores. A representative sample of 1339 respondents was asked their level of agreement to four statements relating to the importance of quality and length of life. Respondents then went on to value 4 EQ-5D 5L states using an online interactive survey and a related set of 6 pairwise health-related choice questions, set up, so that respondents should be indifferent between choice options. We explored the impact of attitudes using regression analysis for TTO values and a logit model for choices. TTO values were correlated with the attitudes and were found to have a residual impact on the choices. In particular, those respondents who preferred quality of life over length of life gave less weight to the differences in years and more weight to differences in quality of life in these choice. We conclude that although the TTO responses reflect attitudes, these attitudes continue to affect health-related choices.

Handling Data Quality Issues to Estimate the Spanish EQ-5D-5L Value Set Using a Hybrid Interval Regression Approach.

BACKGROUND: The Spanish five-level EuroQol five-dimensional questionnaire (EQ-5D-5L) valuation study was the first to use the EuroQol Valuation Technology protocol, including composite time trade-off (C-TTO) and discrete choice experiments (DCE). In this study, its investigators noticed that some interviewers did not fully explain the C-TTO task to respondents. Evidence from a follow-up study in 2014 confirmed that when interviewers followed the protocol, the distribution of C-TTO responses widened. OBJECTIVES: To handle the data quality issues in the C-TTO responses by estimating a hybrid interval regression model to produce a Spanish EQ-5D-5L value set. METHODS: Four different models were tested. Model 0 integrated C-TTO and DCE responses in a hybrid model and models 1 to 3 altered the interpretation of the C-TTO responses: model 1 allowed for censoring of the C-TTO responses, whereas model 2 incorporated interval responses and model 3 included the interviewer-specific protocol violations. For external validation, the predictions of the four models were compared with those of the follow-up study using the Lin's concordance correlation coefficient. RESULTS: This stepwise approach to modeling C-TTO and DCE responses improved the concordance between the valuation and follow-up studies (concordance correlation coefficient: 0.948 [model 0], 0.958 [model 1], 0.952 [model 2], and 0.989 [model 3]). We recommend the estimates from model 3, because its hybrid interval regression model addresses the data quality issues found in the valuation study. CONCLUSIONS: Protocol violations may occur in any valuation study; handling them in the analysis can improve external validity. The resulting EQ-5D-5L value set (model 3) can be applied to inform Spanish health technology assessments.

Reducing preference reversals: The role of preference imprecision and nontransparent methods.

Preferences elicited with matching and choice usually diverge (as characterised by preference reversals), violating a basic rationality requirement, namely, procedure invariance. We report the results of an experiment that shows that preference reversals between matching (Standard Gamble in our case) and choice are reduced when the matching task is conducted using nontransparent methods. Our results suggest that techniques based on nontransparent methods are less influenced by biases (i.e., compatibility effects) than transparent methods. We also observe that imprecision of preferences influences the degree of preference reversals. The preference reversal phenomenon is less strong in subjects with more precise preferences.

Emotions and scope effects in the monetary valuation of health.

This study presents evidence on the role of emotions in the monetary evaluation of health technologies, namely, drug-eluting stents (DES) in our case. It is shown that subjects who are very afraid of having to undergo an angioplasty are: (a) less sensitive to the size of the risk reduction provided by DES and (b) willing to pay more. The lack of scope sensitivity questions the normative validity of the responses of highly emotional subjects. We provide evidence of this effect using what we call the cognitive-emotional random utility model and the responses of a face-to-face, computer-assisted personal interview survey conducted in a representative sample of the Spanish general population (n = 1663).

Risk attitudes in medical decisions for others: An experimental approach.

The aim of this paper is to investigate how risk attitudes in medical decisions for others vary across health contexts. A lab experiment was designed to elicit the risk attitudes of 257 medical and nonmedical students by assigning them the role of a physician who must decide between treatments for patients. An interval regression model was used to estimate individual coefficients of relative risk aversion, and an estimation model was used to test for the effect of type of medical decision and experimental design characteristics on elicited risk aversion. We find that (a) risk attitudes vary across different health contexts, but risk aversion prevails in all of them; (b) students enrolled in health-related degrees show a higher degree of risk aversion; and (c) real rewards for third parties (patients) make subjects less risk-averse. The results underline the importance of accounting for attitudes towards risk in medical decision making.

Improving scope sensitivity in contingent valuation: Joint and separate evaluation of health states.

We present data of a contingent valuation survey, testing the effect of evaluation mode on the monetary valuation of preventing road accidents. Half of the interviewees was asked to state their willingness to pay (WTP) to reduce the risk of having only 1 type of injury (separate evaluation, SE), and the other half of the sample was asked to state their WTP for 4 types of injuries evaluated simultaneously (joint evaluation, JE). In the SE group, we observed lack of sensitivity to scope while in the JE group WTP increased with the severity of the injury prevented. However, WTP values in this group were subject to context effects. Our results suggest that the traditional explanation of the disparity between SE and JE, namely, the so-called "evaluability," does not apply here. The paper presents new explanations based on the role of preference imprecision.

Age effects in mortality risk valuation.

We provide more evidence on the functional relationship between willingness-to-pay for risk reductions and age (the senior discount). We overcome many of the limitations of previous literature that has dealt with this issue, namely, the influence of the assumptions used in statistical models on the final results. Given our large sample size (n = 6024) we can use models that are very demanding on data. We use parametric (linear, quadratic, dummies), semi-nonparametric, and non-parametric models. We also compare the marginal and the total approach and show that they provide similar results. We also overcome one of the limitations of the total approach, that is, we include the effects of socioeconomic characteristics that are correlated with age (education and income). Our main result is that all these different approaches produce very similar results, namely, they show an inverted-U relation between the value of a statistical life (VSL) and age. Those results can hardly be attributed to problems of collinearity, omitted variables or statistical assumptions. We find a clear senior discount effect. This effect seems concentrated on those who have lower education and income levels. We also find that the value of a statistical life year (VSLY) increases with age.

Exploring Differences between TTO and DCE in the Valuation of Health States.

There is recent interest in using discrete choice experiments (DCEs) to derive health state utility values, and results can differ from time tradeoff (TTO). Clearly, DCE is "choice based," whereas TTO is generally considered a "matching" task. We explore whether procedural adaptations to the TTO, which make the method more closely resemble a DCE, make TTO and choice converge. In particular, we test whether making the matching procedure in TTO less "transparent" to the respondent reduces disparities between TTO and DCE. We designed an interactive survey that was hosted on the Internet, and 2022 interviews were achieved in the United Kingdom in a representative sample of the population. We found a marked divergence between TTO and DCE, but this was not related to the "transparency" of the TTO procedure. We conclude that a difference in the error structure between TTO and choice and that factors other than differences in utility are affecting choices is driving the divergence. The latter has fundamental implications for the way choice data are analyzed and interpreted.

Does the Introduction of the Ranking Task in Valuation Studies Improve Data Quality and Reduce Inconsistencies? The Case of the EQ-5D-5L.

BACKGROUND: Time trade-off (TTO)-based valuation studies for the three-level version of the EuroQol five-dimensional questionnaire (EQ-5D) typically started off with a ranking task (ordering the health states by preference). This was not included in the protocol for the five-level EQ-5D (EQ-5D-5L) valuation study. OBJECTIVES: To test whether reintroducing a ranking task before the composite TTO (C-TTO) could help to reduce inconsistencies in C-TTO responses and improve the data quality. METHODS: Respondents were randomly assigned to three study arms. The control arm was the present EQ-5D-5L study protocol, without ranking. The second arm (ranking without sorting) preceded the present protocol by asking respondents to rank the target health states using physical cards. The states were then valued in random order using C-TTO. In the third arm (ranking and sorting), the ranked states remained visible through the C-TTO tasks and the order of valuation was determined by the ranking. The study used only 10 EQ-5D-5L health states. We compared the C-TTO-based inconsistent pairs of health states and ties. RESULTS: The final sample size was 196 in the control arm, 205 in the ranking without sorting arm, and 199 in the ranking and sorting arm. The percentages of ties by respondents were 15.1%, 12.5%, and 12.6% for the control arm, the ranking without sorting arm, and the ranking and sorting arm, respectively. The extra cost for adding the ranking task was about 15%. CONCLUSIONS: The benefit does not justify the effort involved in the ranking task. For this reason, the addition of the ranking task to the present EQ-5D-5L valuation protocol is not an attractive option.

[Monetary value of the human costs of road traffic injuries in Spain]. / La valoración monetaria de los costes humanos de la siniestralidad vial en España.

Cost-benefit analyses in the field of road safety compute human costs as a key component of total costs. The present article presents two studies promoted by the Directorate-General for Traffic aimed at obtaining official values for the costs associated with fatal and non-fatal traffic injuries in Spain. We combined the contingent valuation approach and the (modified) standard gamble technique in two surveys administered to large representative samples (n1=2,020, n2=2,000) of the Spanish population. The monetary value of preventing a fatality was estimated to be 1.4 million euros. Values of 219,000 and 6,100 euros were obtained for minor and severe non-fatal injuries, respectively. These figures are comparable to those observed in neighboring countries.

La valoración monetaria de los costes humanos de la siniestralidad vial en España / Monetary value of the human costs of road traffic injuries in Spain

Los análisis coste-beneficio en el ámbito de la seguridad vial han de computar la totalidad de los costes, y dentro de ellos ocupan un lugar clave los costes humanos. En esta nota se da cuenta de dos estudios promovidos por la Dirección General de Tráfico orientados a la obtención de valores oficiales para España de los costes asociados a las víctimas mortales y no mortales de los accidentes de tráfico. Mediante la combinación del enfoque de la valoración contingente con la técnica de la lotería estándar (modificada), y con muestras amplias (n1=2020, n2=2000) representativas de la población española, se estimó en 1,4 millones de euros el valor monetario de prevenir un fallecido por accidente de tráfico. Para las lesiones graves y leves, los valores estimados fueron de 219.000 y 6100 euros, respectivamente. Las cifras obtenidas tienen un orden de magnitud similar al de los países de nuestro entorno (AU)

Cost-benefit analyses in the field of road safety compute human costs as a key component of total costs. The present article presents two studies promoted by the Directorate-General for Traffic aimed at obtaining official values for the costs associated with fatal and non-fatal traffic injuries in Spain. We combined the contingent valuation approach and the (modified) standard gamble technique in two surveys administered to large representative samples (n1=2,020, n2=2,000) of the Spanish population. The monetary value of preventing a fatality was estimated to be 1.4 million euros. Values of 219,000 and 6,100 euros were obtained for minor and severe non-fatal injuries, respectively. These figures are comparable to those observed in neighboring countries (AU)