Socio-Technological Regimes and Transition Contexts

/pdf/a-review-of-the-use-of-health-status-measures-in-economic-ibyfrktq58.pdf

A review of the use of health status measures in economic evaluation.

Record Status This is a bibliographic record of a published health technology assessment from a member of INAHTA. No evaluation of the quality of this assessment has been made for the HTA database. Citation Billingham L J, Abrams K R, Jones D R. Methods for the analysis of quality-of-life and survival data in health technology assessment. Health Technology Assessment 1999; 3(10): 1-152 Authors' objectives This study identifies and reviews critically the methods proposed for the analysis of quality-of-life and survival data in health technology assessment, particularly those that assess both these endpoints simultaneously. In this way methodology that requires wider dissemination can be identified together with areas requiring further research. It was not within the remit of this study to address issues related to the meaning, definition and measurement of quality of life.

Methods for the analysis of quality-of-life and survival data in health technology assessment.

Objective:To review the use of measures of health status in the assessment of benefits in economic evaluation, whether or not the measures were designed for this purpose.Methods:The review was base...

This paper gives a new explanation for the systematic disparity between standard gamble (SG) utilities and time trade-off (TTO) utilities. The common explanation, which is based on expected utility, is that the disparity is caused by curvature of the utility function for duration. This explanation is, however, incomplete. People violate expected utility and these violations lead to biases in SG and TTO utilities. The paper analyzes the impact on SG and TTO utilities of three main reasons why people violate expected utility: probability weighting, loss aversion, and scale compatibility. In the SG, the combined effect of utility curvature, probability weighting, loss aversion, and scale compatibility is an upward bias. In the TTO these factors lead both to upward and to downward biases. This analysis can also explain the tentative empirical finding that the TTO better describes people's preferences for health than the SG.

A new explanation for the difference between time trade-off utilities and standard gamble utilities.

The time-tradeoff (TTO) test is widely used to measure quality of life for different health states. Subjects are asked to equate the value of living a given period in an inferior health state to the value of living a shorter period in good health. Applications of TTOs have been criticized based on the fact that the value of future life duration is taken as the future life duration itself. The authors show that for a health state in which a subject does not want to live longer than a specified amount of time, subjects' responses do not comply with the assumption that the value of the period in inferior health is equated to the value of the shorter period in good health. Actually, preference reversals with respect to such a health state point to the use of a proportional heuristic in the TTO test. Comparisons of the TTO test in these subjects with category scaling and difference measurements also favor a proportional interpretation of the TTO test. In tests based on conjoint measurement, these subjects also appear to use a proportional heuristic. Consequences of the use of the TTO test and conjoint measurement in quality-of-life models are discussed.

/pdf/proportional-heuristics-in-time-tradeoff-and-conjoint-1fpx0svtmb.pdf

Proportional Heuristics in Time Tradeoff and Conjoint Measurement

Utilities differ according to whether they are derived from risky (gamble) and riskless (visual analog scale, time-tradeoff) assessment methods. The discrepancies are usually explained by assuming that the utilities elicited by risky methods incorporate attitudes towards risk, whereas riskless utilities do not. In (cumulative) prospect theory, risk attitude is conceived as consisting of two components: a decision-weight function (attentiveness to changes in, or sensitivity towards, chance) and a utility function (sensitivity towards outcomes). The authors' data suggest that a framing effect is a hitherto unrecognized and important factor in causing discrepancies between risky and riskless utilities. They collected risky evaluations with the gamble method, and riskless evaluations with difference measurement. Risky utilities were derived using expected-utility theory and prospect theory. With the latter approach, sensitivity towards outcomes and sensitivity towards chance are modeled separately. When the hypothesis that risky utilities from prospect theory coincide with riskless utilities was tested, it was rejected (n = 8, F(1,7) = 132, p = 0.000), suggesting that a correction for sensitivity towards chance is not sufficient to resolve the difference between risky and riskless utilities. Next, it was assumed that different gain/loss frames are induced by risky and riskless elicitation methods. Indeed, identical utility functions were obtained when the gain/loss frames were made identical across methods (n = 7), suggesting that framing was operative. The results suggest that risky and riskless utilities are identical after corrections for sensitivity towards chance and framing.

The discrepancy between risky and riskless utilities: a matter of framing?

textPreference reversals have usually been explained by weighted additive models, in which different tasks give rise to different importance weights for the stimulus attributes, resulting in contradictory trade-offs. This article presents a preference reversal of a more extreme nature. Let (10, 5 Migr) denote living 10 years with a migraine for 5 days per week. Many participants preferred (10, 5 Migr) to (20, 5 Migr). However, when asked to equate these two options with a shorter period of good health, they usually demanded more healthy life years for (20, 5 Migr) than for (10, 5 Migr). This preference reversal within a single dimension cannot be explained by different importance weights and suggests irrationalities at a more fundamental level. Most participants did not change their responses after being confronted with their inconsistencies.

/pdf/preference-reversals-violations-of-unidimensional-procedure-21ffib3owb.pdf

Preference reversals: Violations of unidimensional procedure invariance

The area of social choice (SC) as traditionally conceived deals with a community making a decision starting from and taking into account the preferences of its members. The preferences of the individuals being diverse and the decision sought by the community being unique, SC constitutes a conflict of kind (b). The decision of the community should be based on and in some sense reflect the preferences of the individuals. How to realize this maxim is the concern of SC theory. Coombs and A vrunin proposed the above distinctions only for those kinds of conflict in which the alternatives the conflict is about are clearly distinguished and given a priori. So, the parties in the conflict do agree about what the alternatives are and they know that eventually the conflict is being resolved in one of the pre-given alternatives. Considering a set of cars ordered from low to high quality and, jointly, from low to high price - so that higher quality can only be obtained at higher price - a prospective buyer is torn between low price and high quality (conflict of kind (a)) but eventually decides on one of the pre-given cars in which (s)he deems the trade-off between price and quality optimal. In deciding where to store nuclear waste first a set of feasible sites is determined and, then, one of those sites is eventually chosen although parts of the community may have various and strong opinions on what site is best 15

Social Choice Theory and Practice

https://repub.eur.nl/pub/23110/OnSolving_1995.pdf

Thom Bezembinder

Papers

Proportional Heuristics in Time Tradeoff and Conjoint Measurement

The discrepancy between risky and riskless utilities: a matter of framing?

Preference reversals: Violations of unidimensional procedure invariance

Social Choice Theory and Practice

On solving intransitivities in repeated pairwise choices