Clinical decisions based on complete information are assumed to maximise expected utility. The absence of complete information on the clinical and cost-effectiveness of therapeutics introduces risk and uncertainty in clinical decision making. In this scenario, the optimal treatment pathways regarding patient management may become subjective. Ambiguity in clinical decision making arises when it is not possible to assign a probability to a particular outcome due to limited information. The maximisation of expected utility under ambiguity would, therefore, no longer be assumed to hold. This raises questions regarding clinical decision making under ambiguity. The empirical literature on decision-making under risk and uncertainty has documented ambiguity aversion for moderate likelihood gains and ambiguity seeking for low likelihood loss. In the context of health, however, little is known about how preferences are affected by ambiguity when making decisions across different outcomes. Heterogeneity in attitudes towards ambiguity may explain disparities in clinical decision making, such as treatment allocations, use of diagnostic tests and deviations from clinical guidelines.
We use data from a behavioural economic experiment which aims to assess ambiguity attitudes in two different participant groups across five outcomes of interest. The participant groups include a sample of the UK population as well as a sample of UK clinicians. A laboratory experiment is used to assess ambiguity attitudes for the UK sample following Li et al. (Management Science, 64(7), 2018) with a lab-in-the-field experiment to elicit ambiguity attitudes for UK clinicians. The laboratory and lab-in-the-field experiments both elicit matching probability using Ellsberg’s paradox design. We perform four treatments which differ in the source of uncertainty (i.e., artificial versus realistic) and in the outcome (i.e., monetary versus hypothetical health). We also perform an additional treatment which tests the participants’ choices when provided with information on conformity behaviour among their peers.
Our results extend previous findings in the domain of ambiguity by looking at a broader sample including both the general population and clinicians. The difference between physicians and the general population is particularly relevant in the case of health-related decisions. In particular, we test whether physicians are more rational and more ambiguity seeking than the general population when dealing with health-related decisions. In addition, we link ambiguity attitudes with several socio-demographic characteristics that may explain variation in attitudes towards ambiguity both within and between individuals in the two participant groups. We discuss the implications of early-phase evaluation of new therapeutics in the presence of both ambiguity aversion and ambiguity seeking behaviour for the cost-effectiveness of diagnostics and technologies.