Preference Reversals: Violations of Unidimensional Procedure Invariance

Preference 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

Expected survival with and without second-line palliative chemotherapy: who wants to know?

Background According to surveys, many patients with advancedcancer wish to receive survival information.Objective This study invest igated information preferences by offer-ing patients a decision aid (DA) with infor mation on expected sur-vival for two treatment options: supportive care with or withoutsecond-line palliative chemotherapy. Predicto rs of accepting sur-vival information were explored.Design Eligible patients in this multicentre prospective study wereoffered secon d-line chemotherapy for advanced breast or colorectalcancer. A nurse presented a DA on second-line treatment andasked patients whether they desired information on (i) adverseevents, (ii) tumour response and (iii) survival. Data on 50 clinicaland psychosocial patient characteristics were collected from inclu-sion forms and patient questionnaires.Results Seventy-seven patients received a DA; median age62 years (range 32–80), 61% female, 77% colorectal cancer. Fifty-seven patients (74%; 95% CI 64–84) desired survival information.Four psychosocial characteristics (e.g . deliberative decision style)independently predicted information desire. However, the use ofthese characteristics to predict information desire hardly outper-formed a simple prediction rule.Conclusions Many patients desired information on expected sur-vival when deciding about second-line treatment. However, ourexploratory analysis indicated that patients desiring this informa-tion could not be identified based on their clinical or psychosocialcharacteristics. These findings can help encourage candid discus-sions about expected survival. Health professionals should be care-ful not to make implicit assumptions of information desire based on patient characteristics, but to explicitly ask patients if survivalinformation is desired, and act accordingly

Multinational Evidence of the Applicability and Robustness of Discrete Choice Modeling for Deriving EQ-5D-5L Health-State Values

Aims: To investigate the feasibility of discrete choice experiments for valuing EQ-5D-5L states using computer-based data collection, the consistency of the estimated regression coefficients produced after modeling the preference data, and to examine the similarity of the values derived across countries. Methods: Data were collected in Canada, England, The Netherlands, and the United States (US). Interactive software was developed to standardize the format of the choice tasks across countries, except for face-to-face interviewing in England. The choice task required respondents to choose between 2 suboptimal health states. A Bayesian design was used to generate 200 pairs of states that were randomly grouped into 20 blocks. Each respondent completed 1 block of 10 pairs. A main-effects probit model was used to estimate regression coefficients and to derive values. Results: Approximately 400 respondents participated from each country. The mean time to perform 1 choice task was between 29.2 (US) and 45.2 (England) seconds. All regression coefficients were statistically significant, except level 2 for Usual Activities in The Netherlands (P = 0.51). Predictions for the complete set of 3125 EQ-5D-5L health states were similar for the 4 countries. Intraclass correlation coefficients between the countries were high: from 0.80 (England vs. US) through 0.98 (Canada vs. US). Conclusions: Derivation of value sets from the general population using computer-based choice tasks for the EQ-5D-5L is feasible. Parameter estimates were generally consistent and logical, and health-state values were similar across the 4 countries

The episodic random utility model unifies time trade-off and discrete choice approaches in health state valuation

ABSTRACT: BACKGROUND: To present an episodic random utility model that unifies time trade-off and discrete choice approaches in health state valuation. METHODS: First, we introduce two alternative random utility models (RUMs) for health preferences: the episodic RUM and the more common instant RUM. For the interpretation of time trade-off (TTO) responses, we show that the episodic model implies a coefficient estimator, and the instant model implies a mean slope estimator. Secondly, we demonstrate these estimators and the differences between the estimates for 42 health states using TTO responses from the seminal Measurement and Valuation in Health (MVH) study conducted in the United Kingdom. Mean slopes are estimates with and without Dolan's transformation of worse-than-death (WTD) responses. Finally, we demonstrate an exploded probit estimator, an extension of the coefficient estimator for discrete choice data that accommodates both TTO and rank responses. RESULTS: By construction, mean slopes are less than or equal to coefficients, because slopes are fractions and, therefore, magnify downward errors in WTD responses. The Dolan transformation of WTD responses causes mean slopes to increase in similarity to coefficient estimates, yet they are not equivalent (i.e., absolute mean difference = 0.179). Unlike mean slopes, coefficient estimates demonstrate strong concordance with rank-based predictions (Lin's rho = 0.91). Combining TTO and rank responses under the exploded probit model improves the identification of health state values, decreasing the average width of confidence intervals from 0.057 to 0.041 compared to TTO only results. CONCLUSION: The episodic RUM expands upon the theo

Explanation and elaboration of the Standards for UNiversal reporting of patient Decision Aid Evaluations (SUNDAE) guidelines: examples of reporting SUNDAE items from patient decision aid evaluation literature

This Explanation and Elaboration (E&E) article expands on the 26 items in the Standards for UNiversal reporting of Decision Aid Evaluations (SUNDAE) guidelines. The E&E provides a rationale for each item and includes examples for how each item has been reported in published papers evaluating patient decision aids. The Explanation and Elaboration focuses on items key to reporting studies evaluating patient decision aids and is intended to be illustrative rather than restrictive. Authors and reviewers may wish to use the Explanation and Elaboration broadly to inform structuring of patient decision aid evaluation reports, or use it as a reference to obtain details about how to report individual Checklist items

Standards for UNiversal reporting of patient Decision Aid Evaluation studies: the development of SUNDAE Checklist

Background: Patient decision aids (PDAs) are evidence-based tools designed to help patients make specific and deliberated choices among healthcare options. The International Patient Decision Aid Standards (IPDAS) Collaboration review papers and Cochrane systematic review of PDAs have found significant gaps in the reporting of evaluations of PDAs, including poor or limited reporting of PDA content, development methods, and delivery. This study sought to develop and reach consensus on reporting guidelines to improve the quality of publications evaluating PDAs. Methods: An international workgroup, consisting of members from IPDAS Collaboration, followed established methods to develop reporting guidelines for PDA evaluation studies. This paper describes the results from three completed phases (1) Planning, (2) Drafting, and (3) Consensus, which included a modified, two stage, online international Delphi process. The work was conducted over two years with bi-monthly conference calls and three in-person meetings. The workgroup used input from these phases to produce a final set of recommended items in the form of a checklist. Results: The SUNDAE Checklist (Standards for UNiversal reporting of patient Decision Aid Evaluations) includes 26 items recommended for studies reporting evaluations of PDAs. In the two-stage Delphi process, 117/143 (82%) experts from 14 countries completed round 1 and 96/117 (82%) completed round 2. Respondents reached a high level of consensus on the importance of the items and indicated strong willingness to use the items when reporting PDA studies. Conclusion: The SUNDAE Checklist will help ensure that reports of PDA evaluation studies are understandable, transparent, and of high quality. A separate Explanation and Elaboration publication provides additional details to support use of the Checklist

The effects of lead time and visual aids in TTO valuation: a study of the EQ-VT framework

__Abstract__ __Background__ The effect of lead time in time trade-off (TTO) valuation is not well understood. The purpose of this study was to investigate the effects on health-state valuation of the length of lead time and the way the lead-time TTO task is displayed visually. __Methods__ Using two general population samples, we compared three lead-time TTO variants: 10 years of lead time in full health preceding 5 years of unhealthy time (standard); 5 years of lead time preceding 5 years of unhealthy time (experimental); and 10 years of lead time and 5 years of unhealthy time, presented with a visual aid to highlight the point where the lead time ends (experimental). Participants were randomized to receive one of the lead-time variants, as administered by a computer software program. __Results__ Health-state values generated by TTO valuation tasks using a longer lead time were slightly lower than those generated by tasks using a shorter lead time. When lead time and unhealthy time were presented with visual aids highlighting the difference between the lead time and unhealthy time, respondents spent more time considering health states with a value close to 0. __Conclusions__ Different lead-time time trade-off variants should be carefully studied in order to achieve the best measurement of health-state values using this new method

Cultural Values: Can They Explain Differences in Health Utilities between Countries?

Contains fulltext : 208986.pdf (publisher's version ) (Open Access

Making Composite Time Trade-Off Sensitive for Worse-than-Dead Health States

Objective: The utilities elicited with the composite time trade-off (cTTO) method for health states worse-than-dead (WTD) often correlate poorly with other severity measures, indicating a poor sensitivity of cTTO. We aimed to explore modifications to cTTO to better understand this phenomenon and identify potential improvements. Methods: A total of 480 respondents completed an online TTO interview, each valuing 12 EQ-5D-5L health states. The participants were randomized into four arms, A–D. Arm A followed the standard cTTO, serving as a reference. In arm B, we removed the sorting question comparing immediate death versus 10 years in a valued state. Arm C allowed for utility values &lt;-1 by reducing the time in the valued state in the lead-time TTO (LT-TTO) part of cTTO. In arm D, we randomly selected the starting negative utility in LT-TTO. Utility value distributions, correlations between utilities and level sum score (LSS), and inconsistencies between Pareto-ordered states were analyzed. Results: Arm A replicated the lack of significant correlation between LSS and the negative utility observed in previous work. Of the experimental arms, only arm B exhibited a significant negative correlation. Compared with arm A, arm B produced a higher proportion of WTD states (46.5% versus 26.3%), less negative utility for WTD states on average (-0.571 versus -0.752), and a lower mean censored utility for 55555 (-0.486 versus -0.406). Conclusions: The observed lack of correlation between LSS and utility for WTD states appears linked to the use of comparison with immediate death in the sorting question. LT-TTO is capable of eliciting utility values in a way that is sensitive to severity. Modifying the initial questions in cTTO to identify whether health states are BTD or WTD should be considered.</p

Schrijven van studiemateriaal

Stalmeier, M. (2012, 8 mei). Schrijven van studiemateriaal. Workshop BKO A-0351B, Heerlen, Nederland: Open Universiteit, Instellingsbreed Programma Onderwijs (IPO).Als onderdeel van een BKO cursus ‘Schrijven van studiemateriaal’ wordt een workshop gevolgd. Hierin worden de volgende onderwerpen behandeld: - het formuleren en structureren van leerteksten - het formuleren en structureren van instructieteksten - stijl en formulering van teksten afstemmen op het gebruikte medium (papier of web)