A direct method for measuring discounting and QALYs more easily and reliably.

Time discounting and quality of life are two important factors in evaluations of medical interventions. The measurement of these two factors is complicated because they interact. Existing methods either simply assume one factor given, based on heuristic assumptions, or invoke complicating extraneous factors, such as risk, that generate extra biases.

The metric-frequency measure of similarity for ill-structured data sets, with an application to family therapy.

Similarity measures have been studied extensively in many domains, but usually with well-structured data sets. In many psychological applications, however, such data sets are not available. It often cannot even be predicted how many items will be observed, or what exactly they will entail.

Lessons learned by (from?) an economist working in medical decision making.

This article is a personal account of the author's experiences as an economist working in medical decision making. He discusses the differences between economic decision theory and medical decision making and gives examples of the mutual benefits resulting from interactions. In particular, he discusses the pros and cons of different methods for measuring quality of life (or, as economists would call it, utility), including the standard gamble, the time tradeoff, and the healthy-years equivalent methods.

Explaining the characteristics of the power (CRRA) utility family.

The power family, also known as the family of constant relative risk aversion (CRRA), is the most widely used parametric family for fitting utility functions to data. Its characteristics have, however, been little understood, and have led to numerous misunderstandings. This paper explains these characteristics in a manner accessible to a wide audience.

Correcting biases in standard gamble and time tradeoff utilities.

The standard gamble (SG) method and the time tradeoff (TTO) method are commonly used to measure utilities. However, they are distorted by biases due to loss aversion, scale compatibility, utility curvature for life duration, and probability weighting. This article applies corrections for these biases and provides new data on these biases and their corrections.

The utility of health states after stroke: a systematic review of the literature.

Background: To perform decision analyses that include stroke as one of the possible health states, the utilities of stroke states must be determined. We reviewed the literature to obtain estimates of the utility of stroke and explored the impact of the study population and the elicitation method.

Summary Of Review: We searched various databases for articles reporting empirical assessment of utilities.

Unstable preferences: a shift in valuation or an effect of the elicitation procedure?

Objective: Many studies suggest that impaired health states are valued more positively when experienced than when hypothetical. This study investigated to what extent this discrepancy occurs and examined four possible explanations: non-corresponding description of the hypothetical health state, new understanding due to experience with the health state, valuation shift due to a new status quo, and instability of preference.

Patients And Methods: Fifty-five breast cancer patients evaluated their actually experienced health state, a radiotherapy scenario, and a chemotherapy control scenario before, during, and after postoperative radiotherapy.

Patients' utilities for cancer treatments: a study of the chained procedure for the standard gamble and time tradeoff.

Objective: Temporary health states cannot be measured in the traditional way by means of techniques such as the time tradeoff (TTO) and the standard gamble (SG), where health states are chronic and are followed by death. Chained methods have been developed to solve this problem. This study assesses the feasibility of a chained TTO and a chained SG, and the consistency and concordance between the two methods.

A criticism of healthy-years equivalents.

The following questions describe the scope of this paper. When decision trees are used to analyze optimal decisions, should end nodes be evaluated on the basis of QALYs or on the basis of healthy-years equivalents? Which measures should be used in communications with others, e.g.

Confidence intervals for cost/effectiveness ratios.

The reduction of costs is becoming increasingly important in the medical field. The relevant topic of many clinical trials is not effectiveness per se, but rather cost-effectiveness ratios. Surprisingly, no statistical tools for analyzing cost-effectiveness ratios have been provided in the medical literature yet.

Explaining distortions in utility elicitation through the rank-dependent model for risky choices.

The standard-gamble (SG) method has been accepted as the "gold standard" for the elicitation of utility when risk or uncertainty is involved in decisions, and thus for the measurement of utility in medical decisions. It is based on the assumptions of expected-utility theory. Unfortunately, there is now abundant evidence that expected utility is not empirically valid, and that the SG method overestimates risk aversion and the utilities of impaired health states.