From a different angle: A novel approach to health valuation

The value of a health state is typically described relative to the value of an optimal state, specifically as a ratio ranging from unity (equal to optimal health) to negative infinity. Incorporating potentially infinite values is a challenging issue in the econometrics of health valuation. In this paper, we apply a directional statistics approach based on the assumption of wavering preference. Unlike ratio statistics, directional statistics are based on polar coordinates (angle, radius). The range of angles is bounded between 45 degrees (unity) and negative 90 degrees (i.e., negative infinity); therefore, mean angles are well behaved and negate the impetus behind arbitrary data manipulations. Using time trade-off (TTO) responses from the seminal Measurement and Valuation of Health study, we estimate 243 EQ-5D health state values by minimizing circular variance with and without radial weights. For states with published values greater than zero (i.e., better-than-death), the radially weighted estimates are nearly identical to the published values (Mean Absolute Difference 0.07; Lin’s rho 0.94). For worse-than-death states, the estimates are substantially lower than the published values (Mean Absolute Difference 0.186; Lin’s rho 0.576). For the worst EQ-5D state (33333), the published value is -0.59 and the directional estimate is -1.11. By taking a directional statistics approach, we circumvent problems inherent to ratio statistics and the systematic bias introduced by arbitrary data manipulations. The predictions suggest that published estimates overvalue severe states. This paper examines TTO responses; however, it may be extended to all forms of health valuation

Mathematical Approaches in Economic Evaluations: Applying techniques from different disciplines

Health economics (HE) is a multi-disciplinary field with links to economics, psychology and medicine. This is especially apparent in economic evaluations (EE) which have become an integral part in the management of health care systems in many western countries. In economic evaluations, information on a disease, on the cost of a treatment and on the effectiveness of the treatment is combined into a single mathematical model. This model is then used to assess the cost effectiveness of a treatment for the disease. The mathematical techniques employed to obtain and describe the information originate from three distinct mathematical disciplines associated with economics, psychology and medicine: econometrics, psychometrics and (bio)statistics. Even though there is a large amount of overlap, they all originated as separate disciplines and were developed with different perspectives in mind. This means that researchers in HE have a wide variety of different statistical and mathematical techniques at their disposal. This dissertation shows how ideas and approaches from different disciplines can be applied in solving health economic problems. Basic statistical techniques common to all fields, such as linear regression, are common. They are applied in most of the studies presented in this thesis. In addition to this, the studies described in this thesis show how more specialised techniques and approaches can be used outside the field where they were originally developed. In particular they are used in economic evaluations and the measurement and valuation of health related quality of life

The utilization of constitutional space to maximize sub-national autonomy in federations

Thesis (M.A.) University of Alaska Fairbanks, 2009"The comparative study of federal systems has most often focused on the view of federation 'from the top down.' This is particularly true of the study of constitutionalism in federations, in which federal constitutions have received significantly more attention than sub-national constitutions. An emerging concept in the understanding of federal systems from the sub-national perspective is the idea of constitutional space, which is defined as 'the range of discretion available to the component units in a federal system in designing their constitutional arrangements.' Some scholars have suggested that the full utilization of constitutional space can effectively increase the autonomy of sub-national units within a federation. This thesis explores the potential for increased sub-national autonomy through the utilization of constitutional space in a comparative analysis of state and provincial actions in the United States and Canada with regard to same-sex marriage and resource management, and concludes that due to the influence of additional factors in the federal relationship, the utilization of constitutional space by itself is insufficient to increase sub-national autonomy"--Leaf iii1. Introduction and overview of U.S. and Canadian Federalism -- Introduction -- Constitutional space defined -- Overview of U.S. and Canadian Federalism -- Origins of U.S. and Canadian Federalism -- Formation of the U.S. and Canadian federations -- Evolution of the U.S. and Canadian federations -- Conclusions on the origins, formation, and evolution of the U.S. and Canadian federal systems -- 2. Comparative federalism literature review -- Defining federalism/federation -- Federal vs. national governments -- Distinguishing between federation and confederation -- Origins of federations -- Motivations for forming federal systems -- Why federalism? -- Characteristics of federal systems -- Federalism, ethnic nationalism, and minority rights -- Symmetry vs. asymmetry in federations -- Distribution of power in federal systems -- Representation in federal systems -- Constitutional supremacy in federations -- The question of secession -- Suggestions for further research -- 3. Same-sex marriage and constitutional space -- Same-sex marriage in Canada -- Constitutional authority over marriage in Canada -- Provincial responses to demands for legalization of same-sex marriage -- The notwithstanding clause as a mechanism of provincial constitutional space -- Same-sex marriage in the United States -- The Romer decision and state responses -- Same-sex marriage and constitutional space in California -- Conclusions on the use of constitutional space in relation to conflicts over rights issues in Canada and the United States -- 4. State and provincial constitutional space in resource management -- Land ownership and resource management -- State vs. provincial constitutional arrangements -- Constitutional space and unwritten sub-national constitutions -- Constitutional space and written sub-national constitutions -- Provincial resource management in Canada -- The national energy program -- Impact of the resource amendment -- State resource management in the United States -- Use of the commerce clause to limit state constitutional space in the area of resource management -- State utilization of constitutional space in resource management -- Conclusions on resource management and the use of constitutional space in the United States and Canada -- 5. Conclusion -- Sub-national constitutional space and rights -- Sub-national constitutional space and resource management -- Implications for Alaska -- References

Valuation and modeling of EQ-5D-5L health states using a hybrid approach

Background: The EQ-5D instrument is the most widely used preference-based health-related quality of life questionnaire in cost-effectiveness analysis of health care technologies. Recently, a version called EQ-5D-5L with 5 levels on each dimension was developed. This manuscript explores the performance of a hybrid approach for the modeling of EQ-5D-5L valuation data. Methods: Two elicitation techniques, the composite time trade-off, and discrete choice experiments, were applied to a sample of the Spanish population (n=1000) using a computer-based questionnaire. The sampling process consisted of 2 stages: stratified sampling of geographic area, followed by systematic sampling in each area. A hybrid regression model combining composite time trade-off and discrete choice data was used to estimate the potential value sets using main effects as starting point. The comparison between the models was performed using the criteria of logical consistency, goodness of fit, and parsimony. Results: Twenty-seven participants from the 1000 were removed following the exclusion criteria. The best-fitted model included 2 significant interaction terms but resulted in marginal improvements in model fit compared to the main effects model. We therefore selected the model results with main effects as a potential value set for this methodological study, based on the parsimony criteria. The results showed that the main effects hybrid model was consistent, with a range of utility values between 1 and -0.224. Conclusion: This paper shows the feasibility of using a hybrid approach to estimate a value set for EQ-5D-5L valuation data.</p

Decomposing cross-country differences in quality adjusted life expectancy: the impact of value sets

Background: The validity, reliability and cross-country comparability of summary measures of population health (SMPH) have been persistently debated. In this debate, the measurement and valuation of nonfatal health outcomes have been defined as key issues. Our goal was to quantify and decompose international differences in health expectancy based on health-related quality of life (HRQoL). We focused on the impact of value set choice on cross-country variation. Methods: We calculated Quality Adjusted Life Expectancy (QALE) at age 20 for 15 countries in which EQ-5D population surveys had been conducted. We applied the Sullivan approach to combine the EQ 5D based HRQoL data with life tables from the Human Mortality Database. Mean HRQoL by country gender-age was estimated using a parametric model. We used nonparametric bootstrap techniques to compute confidence intervals. QALE was then compared across the six country-specific time trade-off value sets that were available. Finally, three counterfactual estimates were generated in order to assess the contribution of mortality, health states and healthstate values to cross-country differences in QALE. Results: QALE at age 20 ranged from 33 years in Armenia to almost 61 years in Japan, using the UK value set. The value sets of the other five countries generated different estimates, up to seven years higher. The relative impact of choosing a different value set differed across country-gender strata between 2% and 20%. In 50% of the countrygender strata the ranking changed by two or more positions across value sets. The decomposition demonstrated a varying impact of health states, health-state values, and mortality on QALE differences across countries. Conclusions: The choice of the value set in SMPH may seriously affect cross country comparisons of health expectancy, even across populations of similar levels of wealth and education. In our opinion, it is essential to get more insight into the drivers of differences in health-state values across populations. This will enhance the usefulness of health-expectancy measures.Technology, Policy and Managemen

The Better than Dead Method: Feasibility and Interpretation of a Valuation Study

Background Traditionally, the valuation of health states worse than being dead suffers from two problems: [1] the use of different elicitation methods for positive and negative values, necessitating arbitrary transformations to map negative to positive values; and [2] the inability to quantify that values are time dependent. The Better than Dead (BTD) method is a health-state valuation method where states with a certain duration are compared with being dead. It has the potential to overcome these problems. Objectives To test the feasibility of the BTD method to estimate values for the EQ-5D system. Methods A representative sample of 291 Dutch respondents (aged 18-45 years) was recruited. In a web-based questionnaire, preferences were elicited for a selection of 50 different health states with six durations between 1 and 40 years. Random-effects models were used to estimate the effects of socio-demographic and experimental variables, and to estimate values for the EQ-5D. Test-retest reliability was assessed in 41 respondents. Results Important determinants for BTD were a religious life stance [odds ratio 4.09 (2.00-8.36)] and the educational level. The fastest respondents more often preferred health-state scenarios to being dead and had lower test-retest reliability (0.45 versus 0.77 and 0.84 for fast, medium and slow response times, respectively). The results showed a small number of so-called maximal endurable time states. Conclusion Valuating health states using the BTD method is feasible and reliable. Further research should explore how the experimental setting modifies how values depend on time

Mix and match. A simulation study on the impact of mixed-Treatment comparison methods on health-economic outcomes

Background Decision-Analytic cost-effectiveness (CE) models combine many parameters, often obtained after meta-Analysis. Aim We compared different methods of mixed-Treatment comparison (MTC) to combine transition and event probabilities derived from several trials, especially with respect to health-economic (HE) outcomes like (quality adjusted) life years and costs. Methods Trials were drawn from a simulated reference population, comparing two of four fictitious interventions. The goal was to estimate the CE between two of these. The amount of heterogeneity between trials was varied in scenarios. Parameter estimates were combined using direct comparison, MTC methods proposed by Song and Puhan, and Bayesian generalized linear fixed effects (GLMFE) and random effects models (GLMRE). Parameters were entered into a Markov model. Parameters and HE outcomes were compare