Mortality versus survival graphs: improving temporal consistency in perceptions of treatment effectiveness

Do you want to promote recall, perceptions, or behavior? The best data visualization depends on the communication goal

Data visualizations can be effective and inclusive means for helping people understand health-related data. Yet numerous high-quality studies comparing data visualizations have yielded relatively little practical design guidance because of a lack of clarity about what communicators want their audience to accomplish. When conducting rigorous evaluations of communication (eg, applying the ISO 9186 method), describing the process simply as evaluating "comprehension" or "interpretation" of visualizations fails to do justice to the true range of outcomes being studied. We present newly developed taxonomies of outcome measures and tasks that are guiding a large-scale systematic review of the health numbers communication literature. Using these taxonomies allows a designer to determine whether a specific data presentation format or feature supports or inhibits the desired audience cognitions, feelings, or behaviors. We argue that taking a granular, outcomes-based approach to designing and evaluating information visualization research is essential to deriving practical, actionable knowledge from it.

Effect of different visual presentations on the public's comprehension of prognostic information using acute and chronic condition scenarios: two online randomised controlled trials

OBJECTIVES

To assess the effectiveness of bar graph, pictograph and line graph compared with text-only, and to each other, for communicating prognosis to the public.

DESIGN

Two online four-arm parallel-group randomised controlled trials. Statistical significance was set at p<0.016 to allow for three-primary comparisons.

PARTICIPANTS AND SETTING

Two Australian samples were recruited from members registered at Dynata online survey company. In trial A: 470 participants were randomised to one of the four arms, 417 were included in the analysis. In trial B: 499 were randomised and 433 were analysed.

INTERVENTIONS

In each trial four visual presentations were tested: bar graph, pictograph, line graph and text-only. Trial A communicated prognostic information about an acute condition (acute otitis media) and trial B about a chronic condition (lateral epicondylitis). Both conditions are typically managed in primary care where 'wait and see' is a legitimate option.

MAIN OUTCOME

Comprehension of information (scored 0-6).

SECONDARY OUTCOMES

Decision intention, presentation satisfaction and preferences.

RESULTS

In both trials, the mean comprehension score was 3.7 for the text-only group. None of the visual presentations were superior to text-only. In trial A, the adjusted mean difference (MD) compared with text-only was: 0.19 (95% CI -0.16 to 0.55) for bar graph, 0.4 (0.04 to 0.76) for pictograph and 0.06 (-0.32 to 0.44) for line graph. In trial B, the adjusted MD was: 0.1 (-0.27 to 0.47) for bar graph), 0.38 (0.01 to 0.74) for pictograph and 0.1 (-0.27 to 0.48) for line graph. Pairwise comparisons between the three graphs showed all were clinically equivalent (95% CIs between -1.0 and 1.0). In both trials, bar graph was the most preferred presentation (chosen by 32.9% of trial A participants and 35.6% in trial B).

CONCLUSIONS

Any of the four visual presentations tested may be suitable to use when discussing quantitative prognostic information.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry (ACTRN12621001305819).

Taxonomies for synthesizing the evidence on communicating numbers in health: Goals, format, and structure

Many people, especially those with low numeracy, are known to have difficulty interpreting and applying quantitative information to health decisions. These difficulties have resulted in a rich body of research about better ways to communicate numbers. Synthesizing this body of research into evidence-based guidance, however, is complicated by inconsistencies in research terminology and researcher goals. In this article, we introduce three taxonomies intended to systematize terminology in the literature, derived from an ongoing systematic literature review. The first taxonomy provides a systematic nomenclature for the outcome measures assessed in the studies, including perceptions, decisions, and actions. The second taxonomy is a nomenclature for the data formats assessed, including numbers (and different formats for numbers) and graphics. The third taxonomy describes the quantitative concepts being conveyed, from the simplest (a single value at a single point in time) to more complex ones (including a risk-benefit trade-off and a trend over time). Finally, we demonstrate how these three taxonomies can be used to resolve ambiguities and apparent contradictions in the literature.

Effect of different visual presentations on the comprehension of prognostic information: a systematic review

Background

Understanding prognostic information can help patients know what may happen to their health over time and make informed decisions. However, communicating prognostic information well can be challenging.

Purpose

To conduct a systematic review to identify and synthesize research that has evaluated visual presentations that communicate quantitative prognostic information to patients or the public.

Data sources

MEDLINE, EMBASE, CINAHL, PsycINFO, ERIC and the Cochrane Central Register of Controlled Trials (CENTRAL) (from inception to December 2020), and forward and backward citation search.

Study selection

Two authors independently screened search results and assessed eligibility. To be eligible, studies required a quantitative design and comparison of at least one visual presentation with another presentation of quantitative prognostic information. The primary outcome was comprehension of the presented information. Secondary outcomes were preferences for or satisfaction with the presentations viewed, and behavioral intentions.

Data extraction

Two authors independently assessed risk of bias and extracted data.

Data synthesis

Eleven studies (all randomized trials) were identified. We grouped studies according to the presentation type evaluated. Bar graph versus pictograph (3 studies): no difference in comprehension between the groups. Survival vs mortality curves (2 studies): no difference in one study; higher comprehension in survival curve group in another study. Tabular format versus pictograph (4 studies): 2 studies reported similar comprehension between groups; 2 found higher comprehension in pictograph groups. Tabular versus free text (3 studies): 2 studies found no difference between groups; 1 found higher comprehension in a tabular group.

Limitations

Heterogeneity in the visual presentations and outcome measures, precluding meta-analysis.

Conclusions

No visual presentation appears to be consistently superior to communicate quantitative prognostic information.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12911-021-01612-9.

Numeracy and memory for risk probabilities and risk outcomes depicted on cigarette warning labels

OBJECTIVE

Greater numeracy is associated with higher likelihood to quit smoking. We examined whether numeracy supports learning of numeric health-risk information and, in turn, greater risk perceptions and quit intentions.

METHOD

Adult smokers (N = 696) viewed text warnings with numeric risk information four times each in one of three warning-label types (text-only, low-emotion pictorial [i.e., with image], high-emotion pictorial). They completed posttest measures immediately or 6 weeks later. Emotional reactions to warnings were reported the second time participants viewed the warnings. Numeracy, memory for risk probabilities and risk outcomes, risk perceptions, and quit intentions were assessed postexposures.

RESULTS

Memory for risk probabilities and risk outcomes depended on warning-label type and posttest timing. Consistent with memory-consolidation theory, memory for high- versus low-emotion labels was lower immediately, but declined less for high-than low-emotion labels. Label memory was similar between conditions at 6 weeks. Numeracy predicted overall superior memory (especially for risk probabilities) controlling for health literacy and education. It also indirectly predicted greater risk perceptions and quit intentions via memory. In exploratory analyses, however, the superior recall of risk probabilities of smoking among those higher in numeracy was associated with lower risk perceptions.

CONCLUSIONS

Numeracy is associated with superior risk memory, which relates to greater risk perceptions and quit intentions. More numerate and educated smokers may be better able to quit due to their superior learning of smoking's risks. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Changing Patients' Treatment Preferences and Values with a Decision Aid for Type 2 Diabetes Mellitus: Results from the Treatment Arm of a Randomized Controlled Trial

INTRODUCTION

Failure to intensify treatment for type 2 diabetes mellitus (T2DM) when indicated, or clinical inertia, is a major obstacle to achieving optimal glucose control. This study investigates the impact of a values-focused patient decision aid (PDA) for T2DM antihyperglycemic agent intensification on patient values related to domains important in decision-making and preferred treatments.

METHODS

Patients with poorly controlled T2DM who were taking a metformin-containing regimen were recruited through physicians to access a PDA presenting evidence-based information on T2DM and antihyperglycemic agent class options. Participants' preferences for treatment, decision-making, and the relative importance they placed on various values related to treatment options (e.g., dosing, weight gain, side effects) were assessed before and after interacting with the PDA. Changes from baseline were calculated (post-PDA minus pre-PDA difference) and assessed in univariate generalized linear models exploring associations with patients' personal values.

RESULTS

Analyses included 114 diverse patients from 27 clinics across the US. The importance of avoiding injections, concern about hypoglycemia, and taking medications only once a day significantly decreased after interacting with the PDA [- 1.1 (p = 0.002), - 1.3 (p < 0.001), - 1.1 (p = 0.004), respectively], while the importance of taking medications that avoided weight gain increased [0.8 (p = 0.004)]. Prior to viewing the PDA, most patients (58.8%) had not begun thinking about the decision of adding a medication, and few (12.3%) indicated that they had already made a decision. Post-PDA, 46.5% could state a medication preference.

CONCLUSION

The values-focused PDA for T2DM medication intensification prepared patients to make a shared decision with their clinician and changed patients' values regarding what was important in making that decision. Helping patients understand their options and underlying values can promote shared decision-making and may reduce clinical inertia delaying treatment intensification.

FUNDING

Janssen Scientific Affairs, LLC.

Fixed dose combination therapy loperamide and niacin ameliorates diethylnitrosamine-induced liver carcinogenesis in albino Wistar rats

Hepatocellular carcinoma (HCC) is among the most lethal cancers (five-year survival rates under 11%), which makes it the third most frequent cause of cancer related deaths in men and sixth in women.

The impact of numeracy on verbatim knowledge of the longitudinal risk for prostate cancer recurrence following radiation therapy

OBJECTIVE

. Given the long natural history of prostate cancer, we assessed differing graphical formats for imparting knowledge about the longitudinal risks of prostate cancer recurrence with or without 'hormone' or 'androgen deprivation' therapy.

METHODS

. Male volunteers without a history of prostate cancer were randomized to 1 of 8 risk communication instruments that depicted the likelihood of prostate cancer returning or spreading over 1, 2, and 3 years. The tools differed in format (line, pie, bar, or pictograph) and whether the graph also included no numbers, 1 number (indicating the number of affected individuals), or 2 numbers (indicting both the number affected and the number unaffected). The main outcome variables evaluated were graphical preference and knowledge.

RESULTS

. A total of 420 men were recruited; respondents were least familiar and experienced with pictographs (P < 0.0001), and only 10% preferred this particular format. Overall accuracy ranged from 79% to 92%, and when assessed across all graphical subtypes, the addition of numerical information did not improve verbatim knowledge (P = 0.1). Self-reported numeracy was a strong predictor of accuracy of responses (odds ratio [OR] = 2.6, P = 0.008), and the impact of high numeracy varied across graphical type, having a greater impact on line (OR = 5.1; 95% confidence interval [CI] = 1.6-16; P = 0.04) and pie charts (OR = 7.1; 95% CI = 2.6-19; P =0.01), without an impact on pictographs (OR = 0.4; 95% CI = 0.1-1.7; P = 0.17) or bar charts (OR = 0.5; 95% CI = 0.1-1.8; P = 0.24).

CONCLUSION

. For longitudinal presentation of risk, baseline numeracy was strongly prognostic for outcome. However, the addition of numbers to risk graphs improved only the delivery of verbatim knowledge for subjects with lower numeracy. Although subjects reported the least familiarity with pictographs, they were one of the most effective means of transferring information regardless of numeracy.

Methods for Performing Survival Curve Quality-of-Life Assessments

BACKGROUND

Many medical decisions involve an implied choice between alternative survival curves, typically with differing quality of life. Common preference assessment methods neglect this structure, creating some risk of distortions.

METHODS

Survival curve quality-of-life assessments (SQLA) were developed from Gompertz survival curves fitting the general population's survival. An algorithm was developed to generate relative discount rate-utility (DRU) functions from a standard survival curve and health state and an equally attractive alternative curve and state. A least means squared distance algorithm was developed to describe how nearly 3 or more DRU functions intersect. These techniques were implemented in a program called X-Trade and tested.

RESULTS

SQLA scenarios can portray realistic treatment choices. A side effect scenario portrays one prototypical choice, to extend life while experiencing some loss, such as an amputation. A risky treatment scenario portrays procedures with an initial mortality risk. A time trade scenario mimics conventional time tradeoffs. Each SQLA scenario yields DRU functions with distinctive shapes, such as sigmoid curves or vertical lines. One SQLA can imply a discount rate or utility if the other value is known and both values are temporally stable. Two SQLA exercises imply a unique discount rate and utility if the inferred DRU functions intersect. Three or more SQLA results can quantify uncertainty or inconsistency in discount rate and utility estimates. Pilot studies suggested that many subjects could learn to interpret survival curves and do SQLA.

LIMITATIONS

SQLA confuse some people. Compared with SQLA, standard gambles quantify very low utilities more easily, and time tradeoffs are simpler for high utilities. When discount rates approach zero, time tradeoffs are as informative and easier to do than SQLA.

CONCLUSIONS

SQLA may complement conventional utility assessment methods.

Decision aids: when 'nudging' patients to make a particular choice is more ethical than balanced, nondirective content

Patient decision aids, such as instructional leaflets describing treatment options for prostate cancer, are designed to help educate patients so that they can share in decisions about their care. Developers of these decision aids strive for balance, aiming to be as neutral, unbiased, and nondirective as possible. We argue that balance should not always be a goal, and we identify three situations where it should not be. For example, men diagnosed with early-stage prostate cancer frequently are not advised by their physicians that active surveillance is a reasonable alternative to immediate surgery or radiation. It may be desirable to design decision aids that promote active surveillance as an option. We recognize that the arguments put forth in this article are controversial. But they are also justified. We challenge medical decision makers and decision aid developers to determine if and when patients should be "nudged" toward one option or another.

Presenting quantitative information about decision outcomes: a risk communication primer for patient decision aid developers

BACKGROUND

Making evidence-based decisions often requires comparison of two or more options. Research-based evidence may exist which quantifies how likely the outcomes are for each option. Understanding these numeric estimates improves patients' risk perception and leads to better informed decision making. This paper summarises current "best practices" in communication of evidence-based numeric outcomes for developers of patient decision aids (PtDAs) and other health communication tools.

METHOD

An expert consensus group of fourteen researchers from North America, Europe, and Australasia identified eleven main issues in risk communication. Two experts for each issue wrote a "state of the art" summary of best evidence, drawing on the PtDA, health, psychological, and broader scientific literature. In addition, commonly used terms were defined and a set of guiding principles and key messages derived from the results.

RESULTS

The eleven key components of risk communication were: 1) Presenting the chance an event will occur; 2) Presenting changes in numeric outcomes; 3) Outcome estimates for test and screening decisions; 4) Numeric estimates in context and with evaluative labels; 5) Conveying uncertainty; 6) Visual formats; 7) Tailoring estimates; 8) Formats for understanding outcomes over time; 9) Narrative methods for conveying the chance of an event; 10) Important skills for understanding numerical estimates; and 11) Interactive web-based formats. Guiding principles from the evidence summaries advise that risk communication formats should reflect the task required of the user, should always define a relevant reference class (i.e., denominator) over time, should aim to use a consistent format throughout documents, should avoid "1 in x" formats and variable denominators, consider the magnitude of numbers used and the possibility of format bias, and should take into account the numeracy and graph literacy of the audience.

CONCLUSION

A substantial and rapidly expanding evidence base exists for risk communication. Developers of tools to facilitate evidence-based decision making should apply these principles to improve the quality of risk communication in practice.

Deciding what type of evidence and outcomes to include in guidelines: article 5 in Integrating and coordinating efforts in COPD guideline development. An official ATS/ERS workshop report

INTRODUCTION

Professional societies, like many other organizations around the world, have recognized the need to use more rigorous processes to ensure that health care recommendations are informed by the best available research evidence. This is the fifth of a series of 14 articles that were prepared by an international panel to advise guideline developers in respiratory and other diseases on approaches for guideline development. This article focuses on what type of evidence and outcomes to include in guidelines.

METHODS

In this review we addressed the following topics and questions. (1) What methods should be used to select important outcomes? (2) What types of outcomes should be considered? (3) What sources of evidence should be considered? (4) How should the importance of outcomes be ranked? (5) How to deal with surrogate outcomes. (6) What issues related to outcomes should be considered in the evidence review? (7) What quality of evidence should be used? (8) How to interpret the effect on outcomes. (9) How to incorporate outcomes related to harm. We based our responses on a PubMed literature review, prior reviews, relevant methodological research, and workshop discussions.

RESULTS AND DISCUSSION

Guideline panels should use transparent and systematic methods to select both the evidence and important outcomes, with input from groups that represent a wide range of expertise and constituencies. Outcomes should address both benefits and downsides, with consideration of the definitions, severity, and time course of the outcomes. Guideline panels should use a transparent approach to rank outcome importance recognizing that stakeholder and patient values and preferences may vary. Intermediate and surrogate outcomes are frequently reported, but their correlation with patient important outcomes may be low. A guideline panel should determine a priori the magnitude of effect judged clinically significant, factors that may influence outcome reporting, and whether different ways of measuring the outcomes permit the outcomes to be combined. Comprehensive identification of the evidence includes the use of multiple data sources. While randomized controlled trials (RCTs) provide the highest quality evidence, reviewers of evidence also need to consider nonrandomized studies such as case series, registries, and case-control studies if randomized trials are not available. This is particularly true for harms. The outcomes reported from RCTs may not always directly apply to clinical practice settings (i.e., they may not be generalizable).

Simple and multistate survival curves: can people learn to use them?

OBJECTIVE AND SAMPLE: This investigation assessed the comprehension of survival curves in a community sample of 88 young and middle-aged adults when several aspects of good practice for graphical communication were implemented, and it compared comprehension for alternative presentation formats. DESIGN, METHOD, and

MEASUREMENTS

After reading worked examples of using survival curves that provided explanation and answers, participants answered questions on survival data for pairs of treatments. Study 1 compared presenting survival curves for both treatments on the same figure against presentation via 2 separate figures. Study 2 compared presenting data for 3 possible outcome states via a single "multistate" figure for each treatment against presenting each outcome on a separate figure (with both treatments on the same figure). Both studies compared alternative forms of questioning (e.g., "number alive" versus "number dead"). Numeracy levels (self-rated and objective measures) were also assessed.

RESULTS

Comprehension was generally good--exceeding 90% correct answers on half the questions--and was similar across alternative graphical formats. Lower accuracy was observed for questions requiring a calculation but was significantly lower only when the requirement for calculation was not explicit (13%-28% decrements in performance). In study 1, this effect was most acute for those with lower levels of numeracy. Subjective (self-rated) numeracy and objective (measured) numeracy were both moderate positive predictors of overall task accuracy (r ≈ 0.3).

CONCLUSIONS

A high degree of accuracy in extracting information from survival curves is possible, as long as any calculations that are required are made explicit (e.g., finding differences between 2 survival rates). Therefore, practitioners need not avoid using survival curves in discussions with patients, although clear and explicit explanations are important.

Helping patients decide: ten steps to better risk communication

With increasing frequency, patients are being asked to make complex decisions about cancer screening, prevention, and treatment. These decisions are fraught with emotion and cognitive difficulty simultaneously. Many Americans have low numeracy skills making the cognitive demands even greater whenever, as is often the case, patients are presented with risk statistics and asked to make comparisons between the risks and benefits of multiple options and to make informed medical decisions. In this commentary, we highlight 10 methods that have been empirically shown to improve patients' understanding of risk and benefit information and/or their decision making. The methods range from presenting absolute risks using frequencies (rather than presenting relative risks) to using a risk format that clarifies how treatment changes risks from preexisting baseline levels to using plain language. We then provide recommendations for how health-care providers and health educators can best to communicate this complex medical information to patients, including using plain language, pictographs, and absolute risks instead of relative risks.

Risky feelings: why a 6% risk of cancer does not always feel like 6%

OBJECTIVE

Emotion plays a strong role in the perception of risk information but is frequently underemphasized in the decision-making and communication literature. We sought to discuss and put into context several lines of research that have explored the links between emotion and risk perceptions.

METHODS

In this article, we provide a focused, "state of the science" review of research revealing the ways that emotion, or affect, influences people's cancer-related decisions. We identify illustrative experimental research studies that demonstrate the role of affect in people's estimates of cancer risk, their decisions between different cancer treatments, their perceptions of the chance of cancer recurrence, and their reactions to different methods of presenting risk information.

RESULTS

These studies show that people have strong affective reactions to cancer risk information and that the way risk information is presented often determines the emotional gist people take away from such communications.

CONCLUSION

Cancer researchers, educators and oncologists need to be aware that emotions are often more influential in decision making about cancer treatments and prevention behaviors than factual knowledge is.

PRACTICE IMPLICATIONS

Anticipating and assessing affective reactions is an essential step in the evaluation and improvement of cancer risk communications.

What constitutes evidence-based patient information? Overview of discussed criteria

OBJECTIVE

To survey quality criteria for evidence-based patient information (EBPI) and to compile the evidence for the identified criteria.

METHODS

Databases PubMed, Cochrane Library, PsycINFO, PSYNDEX and Education Research Information Center (ERIC) were searched to update the pool of criteria for EBPI. A subsequent search aimed to identify evidence for each criterion. Only studies on health issues with cognitive outcome measures were included. Evidence for each criterion is presented using descriptive methods.

RESULTS

3 systematic reviews, 24 randomized-controlled studies and 1 non-systematic review were included. Presentation of numerical data, verbal presentation of risks and diagrams, graphics and charts are based on good evidence. Content of information and meta-information, loss- and gain-framing and patient-oriented outcome measures are based on ethical guidelines. There is a lack of studies on quality of evidence, pictures and drawings, patient narratives, cultural aspects, layout, language and development process.

CONCLUSION

The results of this review allow specification of EBPI and may help to advance the discourse among related disciplines. Research gaps are highlighted.

PRACTICE IMPLICATIONS

Findings outline the type and extent of content of EBPI, guide the presentation of information and describe the development process.

The impact of the format of graphical presentation on health-related knowledge and treatment choices

OBJECTIVE

To evaluate the ability of six graph formats to impart knowledge about treatment risks/benefits to low and high numeracy individuals.

METHODS

Participants were randomized to receive numerical information about the risks and benefits of a hypothetical medical treatment in one of six graph formats. Each described the benefits of taking one of two drugs, as well as the risks of experiencing side effects. Main outcome variables were verbatim (specific numerical) and gist (general impression) knowledge. Participants were also asked to rate their perceptions of the graphical format and to choose a treatment.

RESULTS

2412 participants completed the survey. Viewing a pictograph was associated with adequate levels of both types of knowledge, especially for lower numeracy individuals. Viewing tables was associated with a higher likelihood of having adequate verbatim knowledge vs. other formats (p<0.001) but lower likelihood of having adequate gist knowledge (p<0.05). All formats were positively received, but pictograph was trusted by both high and low numeracy respondents. Verbatim and gist knowledge were significantly (p<0.01) associated with making a medically superior treatment choice.

CONCLUSION

Pictographs are the best format for communicating probabilistic information to patients in shared decision making environments, particularly among lower numeracy individuals.

PRACTICE IMPLICATIONS

Providers can consider using pictographs to communicate risk and benefit information to patients of different numeracy levels.

Clinical implications of numeracy: theory and practice

BACKGROUND

Low numeracy is pervasive and constrains informed patient choice, reduces medication compliance, limits access to treatments, impairs risk communication, and affects medical outcomes; therefore, it is incumbent upon providers to minimize its adverse effects.

PURPOSE

We provide an overview of research on health numeracy and discuss its implications in clinical contexts.

CONCLUSIONS

Low numeracy cannot be reliably inferred on the basis of patients' education, intelligence, or other observable characteristics. Objective and subjective assessments of numeracy are available in short forms and could be used to tailor health communication. Low scorers on these assessments are subject to cognitive biases, irrelevant cues (e.g., mood), and sharper temporal discounting. Because prevention of the leading causes of death (e.g., cancer and cardiovascular disease) depends on taking action now to prevent serious consequences later, those low in numeracy are likely to require more explanation of risk to engage in prevention behaviors. Visual displays can be used to make numerical relations more transparent, and different types of displays have different effects (e.g., greater risk avoidance). Ironically, superior quantitative processing seems to be achieved by focusing on qualitative gist and affective meaning, which has important implications for empowering patients to take advantage of the evidence in evidence-based medicine.

Numeric, verbal, and visual formats of conveying health risks: suggested best practices and future recommendations

Perception of health risk can affect medical decisions and health behavior change. Yet the concept of risk is a difficult one for the public to grasp. Whether perceptions of risk affect decisions and behaviors often relies on how messages of risk magnitudes (i.e., likelihood) are conveyed. Based on expert opinion, this article offers, when possible, best practices for conveying magnitude of health risks using numeric, verbal, and visual formats. This expert opinion is based on existing empirical evidence, review of papers and books, and consultations with experts in risk communication. This article also discusses formats to use pertaining to unique risk communication challenges (e.g., conveying small-probability events, interactions). Several recommendations are suggested for enhancing precision in perception of risk by presenting risk magnitudes numerically and visually. Overall, there are little data to suggest best practices for verbal communication of risk magnitudes. Across the 3 formats, few overall recommendations could be suggested because of 1) lack of consistency in testing formats using the same outcomes in the domain of interest, 2) lack of critical tests using randomized controlled studies pitting formats against one another, and 3) lack of theoretical progress detailing and testing mechanisms why one format should be more efficacious in a specific context to affect risk magnitudes than others. Areas of future research are provided that it is hoped will help illuminate future best practices.