The value of statistical life in the context of road safety: new evidence on the contingent valuation/standard gamble chained approach

This study estimates the value of statistical life (VSL) on a road traffic accident using the Contingent Valuation/Standard Gamble chained approach. A large representative sample (n = 2020) is used to calculate a VSL for use in the evaluation of road safety programmes in Spain. The paper also makes some methodological contributions, by providing new evidence about the consistency of the chained method. Our main results are: (1) A range from 1.3 million euro to 1.7 million euro is obtained for the VSL in Spain in the context of road accidents. This range is in line with the values used in the same context in other European countries, although it is lower than those obtained in different contexts and with other methods. (2) The method performs much better in terms of scope sensitivity than the traditional contingent valuation method, which asks subjects about their willingness to pay for very small reductions in the risk of death. (3) We introduce a new ‘indirect’ chaining approach which reduces (but does not remove) the disparity between direct and indirect chaining approaches. More extreme VSL estimates are still obtained with this indirect method than with the direct one. (4) VSL estimates depend on the injury used. More specifically, we obtained a lower VSL when a more severe injury is used. (5) Framing the risk of death in the modified standard gamble question as “10n in 10,000” instead of “n in 1000” influences the value of VSL. We attribute this effect to the Ratio Bias.

Feasibility of assessing utilities with a single-item standard gamble questionnaire in patients with melanoma

Objectives To determine the feasibility of eliciting utilities with a standard gamble self-completion questionnaire that uses a single-item approach in melanoma patients. Methods 150 patients with low-risk melanoma completed a paper standard gamble questionnaire. Six scenarios described the adjuvant treatment of high-risk melanoma with interferon alfa-2b with varied side effects. Patients were asked to directly state the maximum death risk they would accept to prevent these health states. Methods were the same as in a study by Kilbridge et al. (J Clin Oncol 19(3):812–823, 2021. 10.1200/JCO.2001.19.3.812), except that they used computerised interviews and an iterative risk variation (Ping–Pong method) to elicit utilities. Results The rate of missing values in the standard gamble was 1.0%. The percentage of patients who misordered scenarios was very similar to the reference study (11.3% vs. 11.2%). Mean utilities were also similar with a maximum difference of 0.02 points, but median utilities were not (between 0.21 points below and 0.05 points above the reference study). Conclusions One-item utility elicitation with questionnaires might be a feasible alternative to computerised face-to-face interviews to conduct a standard gamble in melanoma patients.

Modeling SF-6D Health Utilities: Is Bayesian Approach Appropriate?

Background: Valuation studies of preference-based health measures like SF6D have been conducted in many countries. However, the cost of conducting such studies in countries with small populations or low- and middle-income countries (LMICs) can be prohibitive. There is potential to use results from readily available countries’ valuations to produce better valuation estimates. Methods: Data from Lebanon and UK SF-6D value sets were analyzed, where values for 49 and 249 health states were extracted from samples of Lebanon and UK populations, respectively, using standard gamble techniques. A nonparametric Bayesian model was used to estimate a Lebanon value set using the UK data as informative priors. The resulting estimates were then compared to a Lebanon value set obtained using Lebanon data by itself via various prediction criterions. Results: The findings permit the UK evidence to contribute potential prior information to the Lebanon analysis by producing more precise valuation estimates than analyzing Lebanon data only under all criterions used. Conclusions: The positive findings suggest that existing valuation studies can be merged with a small valuation set in another country to produce value sets, thereby making own country value sets more attainable for LMICs.

Health Preference Measures in Patients with Obstructive Sleep Apnea Syndrome Undergoing Continuous Positive Airway Pressure Therapy: Data from a Randomized Trial

<b><i>Background:</i></b> In patients with obstructive sleep apnea syndrome (OSAS), the preference-based, health-related quality of life in terms of utility has not been extensively studied. <b><i>Objective:</i></b> To address this point, we compared the performance of different instruments assessing utility in patients with OSAS undergoing continuous positive airway pressure (CPAP) therapy. <b><i>Materials and Methods:</i></b> Data of 208 patients with OSAS (28 women, mean ± SE age 54.4 ± 0.7 years, apnea-hypopnea index (AHI) 51.9 ± 1.8/h, Epworth sleepiness score 13.4 ± 0.2) participating in a randomized trial of different CPAP modalities over 2 years were analyzed. Evaluations included sleep studies, Epworth sleepiness scale, and several utility instruments that measure subjective health preference on a scale ranging from 1 (most preferred and perfect health) to 0 (least preferred and very poor health). <b><i>Results:</i></b> After 2 years of CPAP therapy, the mean ± SE AHI was 6.7 ± 1.5/h and Epworth score 7.9 ± 0.4, both <i>p</i> &#x3c; 0.001 versus baseline. Baseline utilities and changes (95% confidence interval) after 2 years of CPAP therapy were EuroQol 5-dimensions 0.79 ± 0.01, 0.02 (0.00–0.05, <i>p</i> = 0.064); short-form 6-dimension medical outcome questionnaire 0.72 ± 0.01, 0.06 (0.04–0.08, <i>p</i> &#x3c; 0.001); Euro-thermometer visual analog scale 0.70 ± 0.01, 0.09 (0.07–0.12, <i>p</i> &#x3c; 0.001); time trade-off 0.82 ± 0.01, 0.03 (0.01–0.06, <i>p</i> = 0.002); and standard gamble 0.82 ± 0.01, −0.01 (−0.03 to 0.02, <i>p</i> = 0.712). <b><i>Conclusion:</i></b> The short-form 6-dimensions questionnaire, the Euro-thermometer, and the time trade-off instruments reflected the major clinical improvements in OSAS, while the EuroQoL 5-dimensions and standard gamble tests were not sensitive to CPAP effects. These results indicate that the evaluation of utility of a treatment for OSAS depends critically on the instrument used, which is important from an individual and societal perspective.

Willingness to Pay Tuition and Risk-Taking Proclivities Among Students During the Covid-19 Pandemic: A Fundamental Conundrum for Universities

Background. As universities around the world decide whether to remain open or to close their campuses because of the COVID-19 pandemic, they often are doing so without objective information on the preferences and risk tolerance of their students. In this study, we aim to quantify students’: 1) risk tolerance for in-person instruction; 2) willingness to pay for in-person instruction versus online-only instruction; and 3) risk-tolerance for social activities held off campus.Methods. We developed an automated survey tool that administered a “standard gamble” exercise grounded in game theory to 46 Columbia University public health graduate students who were knowledgeable about COVID-19 and who had experience with both online and offline coursework. Students were asked to trade between the risk of becoming infected with COVID-19 and: 1) attending classes in-person versus online and 2) attending parties in the greater New York City area. We also assessed their willingness to pay for online only tuition and plans to travel off campus.Results. On average, students were willing to accept a 23% (standard error [SE]: 4%) risk of infection on campus over the semester in exchange for the opportunity to attend classes in-person. Students were willing-to-pay only 48% (SE: 3%) of typical in-person tuition were courses held exclusively online, and no students were willing to pay full price for online-only instruction. Students planned to leave campus an average of 3.6 times per week (SE: 0.54), and 15% of the students would be willing to attend a party in the community surrounding the university even if the prevalence of circulating COVID-19 were high.Conclusions. Students with a strong knowledge of COVID-19 transmission and risks are an enigma: they are willing to pay only around 50% for online classes but likely to engage in activities that present significant barriers to holding in-person classes. This enigma underscores the conundrum facing universities.Trial registration: NA.

Direct and indirect utilities of patients with mild to moderate versus severe carpal tunnel syndrome

Health utility is a quantitative global measure of patients’ health status. This retrospective cohort study aimed to compare health utilities of patients with mild to moderate versus severe carpal tunnel syndrome and determine inter-instrumental agreement. Health utilities of 29 patients with varying severity of carpal tunnel syndrome were measured indirectly by Short-Form Sixth Dimension and EuroQol 5D questionnaire and directly by Chained Standard Gamble and a visual analogue scale. Health utility was 0.69 for Short-Form Sixth Dimension, 0.78 for EuroQol 5D Questionnaire, 0.98 for Chained Standard Gamble, and 0.76 for the visual analogue scale. There was a significant inter-instrumental agreement between three of the instruments, but not the Chained Standard Gamble. The difference in health utilities between patients with mild or moderate versus severe carpal tunnel syndrome was significant only for the EuroQol 5D questionnaire. We conclude based on our results that there are no clear indications on how health utilities can be integrated into decision analysis models and economic evaluation regarding carpal tunnel syndrome of various severities . Level of evidence: IV

A comparison of individual and collective decision making for standard gamble and time trade-off

Quality-Adjusted Life-Years (QALYs) are typically derived from individual preferences over health episodes. This paper reports the first experimental investigation into the effects of collective decision making on health valuations, using both time trade-off (TTO) and standard gamble (SG) tasks. We investigated collective decision making in dyads, by means of a mixed-subjects design where we control for learning effects. Our data suggest that collective decision making has little effect on decision quality, as no effects were observed on decision consistency and monotonicity for both methods. Furthermore, QALY weights remained similar between individual and collective decisions, and the typical difference in elicited weights between TTO and SG was not affected. These findings suggest that consulting with others has little effect on health state valuation, although learning may have. Additionally, our findings add to the literature of the effect of collective decision making, suggesting that no such effect occurs for TTO and SG.