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UBC Theses and Dissertations

How do current approaches to communicating ambiguity in risk estimates influence decisions? Hicklin, James Gregory


Background: Uncertain outcomes are an unavoidable fact of medicine. First-order uncertainty (e.g. “10 in 100 people can expect an outcome in the next year”) has well-established guidelines as to how it should be best presented, but it is not clear if and how to present second-order uncertainty, referred to as ambiguity (e.g. “10 [95% CI 5,15] in 100”). Objectives: To explore the ways in which ambiguity in risk is currently being described to patients by (1) identifying existing presentation techniques and evidence for their potential impact on decision-making, (2) investigating how presentation techniques influence decision-related outcomes, including intention, trust, worry, decisional uncertainty, risk perception, knowledge and preference, and (3) determining which techniques should be investigated further. Methods: The literature on current techniques to present ambiguity was systematically reviewed through an electronic search of the Medline/PubMed database, and an existing database of patient decision support interventions. The influence of each identified communication technique was evaluated by the design and implementation of a web-survey in a hypothetical atrial fibrillation vignette. Results: Nine distinct presentation techniques were identified as having been used in the past, and were shown to influence decision-making outcomes. Of these techniques, the visual and textual range techniques were found to result in change in intention (in both directions) which was statistically significant, while other techniques decreased trust, increased decisional uncertainty, and resulted in greater knowledge. Conclusions: Techniques that resulted in the worst knowledge of the range in risk scores tended to be the ones that were preferred by participants. Yet, without good knowledge of risks involved with different medical options, informed consent, and value-based decisions are challenging. Findings from this work indicate that some techniques for presenting uncertainty, such as the visual and textual range techniques, impact various psychometric outcomes related to decision-making, including intention to take oral anticoagulation, trust in risk estimates, decisional uncertainty and knowledge of ambiguity. Further research should focus on testing the influence of these techniques on decision-making related outcomes.

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