Current Challenges When Using Numbers in Patient Decision Aids: Advanced Concepts

Abstract

Background Decision aid developers have to convey complex task-specific numeric information in a way that minimizes bias and promotes understanding of the options available within a particular decision. Whereas our companion paper summarizes fundamental issues, this article focuses on more complex, task-specific aspects of presenting numeric information in patient decision aids. Methods As part of the International Patient Decision Aids Standards third evidence update, we gathered an expert panel of 9 international experts who revised and expanded the topics covered in the 2013 review working in groups of 2 to 3 to update the evidence, based on their expertise and targeted searches of the literature. The full panel then reviewed and provided additional revisions, reaching consensus on the final version. Results Five of the 10 topics addressed more complex task-specific issues. We found strong evidence for using independent event rates and/or incremental absolute risk differences for the effect size of test and screening outcomes. Simple visual formats can help to reduce common judgment biases and enhance comprehension but can be misleading if not well designed. Graph literacy can moderate the effectiveness of visual formats and hence should be considered in tool design. There is less evidence supporting the inclusion of personalized and interactive risk estimates. Discussion More complex numeric information. such as the size of the benefits and harms for decision options, can be better understood by using incremental absolute risk differences alongside well-designed visual formats that consider the graph literacy of the intended audience. More research is needed into when and how to use personalized and/or interactive risk estimates because their complexity and accessibility may affect their feasibility in clinical practice.

Comparing the impact of an icon array versus a bar graph on preference and understanding of risk information: Results from an online, randomized study

“…These differences are a limitation, but they are also a result of feedback from the user-testing phase of development. Further, a participant's preference for a type of graphical display format does not necessarily translate to having a greater understanding of the risk information, so the findings regarding preference need to be interpreted with caution [41]. Lastly, we are cognizant that the formats used in this study focus on one…”

Numeracy and the Motivational Mind: The Power of Numeric Self-efficacy

“…These skills are necessary but appear insufficient sometimes because patients also need numeric confidence to persist with difficult and/or tedious numeric tasks over time, including in the face of obstacles. 10,47 Some lupus interventions and lifestyle changes, for example, may require persisting and doing the same numeric task again and again, such as titrating medications, adopting healthy behaviors, and showing up for appointments on time.…”

Vitruvian plot: a visualisation tool for multiple outcomes in network meta-analysis

“…e5 These methods, however, are only fit to simultaneously show results regarding a small number of outcomes, limiting the overall interpretation of findings 9 10. Alternative methods to visualise multiple outcomes from NMAs have been proposed,11–14 ,e6-e10 with only limited consistency with good practice guidelines for communicating benefit–risk information 6 15–18. For instance, some tools prioritised the textual information over the graphical communication, with the latter limited to the use of numbers in coloured tables 12 .…”