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New paper on surrogate decision making published in BMJ Open

Posted on Thursday, Aug 02 2018

If a patient is no longer able to express his or her treatment preferences (e.g., due to an accident or due to dementia), a surrogate may need to make medical decisions on behalf of this person. Such "surrogate decisions" are among the most difficult decisions under uncertainty that we have to make in our lives. So how to best make surrogate decisions?

In our previous research (Frey, Hertwig, & Herzog, 2014) we found that different approaches to surrogate decision making (e.g., a patient-designated surrogate; all family members rendering a joint decision; etc.) do not differ substantially in terms of their "predictive accuracy". Therefore, in our most recent paper published in the British Medical Journal: Open (Frey, Herzog, & Hertwig, 2018) we investigated people's "procedural preferences". Specifically, how strongly do people endorse different approaches to surrogate decision making?

The figure above shows the results from two representative population surveys that we conducted in Germany and Switzerland. People reported their procedural preferences for six different approaches to surrogate decision making, either from the perspective of an incapacitated patient or from the perspective of a potential surrogate for an incapacitated family member. Fortunately, the procedural preferences of potential "patients" and "surrogates" were mostly aligned. Yet, endorsements for the different approaches varied markedly (see figure). These findings may have direct implications for clinicians and policy makers, as current legislations only provide for individualistic approaches. You can learn more about this topic under my research section on medical decision making and by downloading our paper with the detailed results.

Frey, R., Herzog, S. M., & Hertwig, R. (2018). Deciding on behalf of others: A population survey on procedural preferences for surrogate decision-making. BMJ Open, 8, e022289. doi:10.1136/bmjopen-2018-022289 | PDF

SNSF Ambizione project started

Posted on Tuesday, Jan 16 2018

Together with my new Ph.D. student Markus Steiner, I have started to work on an SNSF Ambizione project entitled "Mapping the ecology of risk taking: A test of the generalizability of the construct risk preference to real-life behaviors." During the next four years we will run a series of lab studies and ecological assessments to i) address open issues regarding the measurement of risk preference, ii) to better understand the ecology of risk-taking behaviors in the modern society, and iii) to evaluate the predictive validity of different measures of risk preference for important life outcomes. You can learn more about this project in my research section.
Two new papers on risk preference

Posted on Wednesday, Oct 04 2017

The two core papers of the Basel-Berlin Risk Study have recently been published and are now available online (please see below for the full references). In these two publications we investigated the extent to which there is a general factor of risk preference (akin to g, the general factor of intelligence), and whether risk preference can be considered a stable psychological trait. We addressed these questions by implemented 39 risk-taking measures from three different measurement traditions: Propensity measures assessing "stated preferences", (incentivized) behavioral measures assessing "revealed preferences", and frequency measures assessing actual real-world risky activities. This battery was completed by 1,507 participants, with 109 participants completing a retest–session after a period of six months.

The results indicate that the propensity and frequency measures converge relatively well, thus forming a "positive manifold", whereas the (incentivized) behavioral measures show poor consistency (with the measures of the other measurement traditions, but also between each other). Moreover, our findings suggest that there is a broad general factor of risk preference, R, that accounts for 61% of the explained variance. This general factor is complemented by a series of domain-specific factors. Finally, the general factor proved to be highly reliable across a period of six months. To learn more about these results, please have a look at:

Frey, R., Pedroni, A., Mata, R., Rieskamp, J., & Hertwig, R. (2017). Risk preference shares the psychometric structure of major psychological traits. Science Advances, 3, e1701381. doi:10.1126/sciadv.1701381 | PDF

A second paper focuses exclusively on the behavioral measures (using the same dataset) and reports an extensive cognitive modeling analysis. The goal of this analysis was to investigate potential reasons for the lack of consistency across the various behavioral elicitation methods. People were found to differ substantially in the strategies they used in the various tasks, yet they did not do so in a very systematic way. Even at the level of model parameters, the consistency across behavioral tasks was poor, thus further calling into question the validity of behavioral measures as indicators of a person's risk preference. The detailed analyses on the behavioral tasks are published in:

Pedroni, A., Frey, R., Bruhin, A., Dutilh, G., Hertwig, R., & Rieskamp, J. (2017). The risk elicitation puzzle. Nature Human Behaviour, 1, 803-809. doi:10.1038/s41562-017-0219-x

All in all, our results suggest that risk preference has a similar psychometric structure as other major traits. In particular the observation of the general and stable factor may have important implications for future investigations of the biological foundations of risk preference. Moreover, as the lack of consistency across behavioral tasks showed, more attention needs to be given to the assessment of risk preference. For more information, please also have a look at my research section!
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