Further insight into the perception of quantitative information: judgments of gist in treatment decisions

Numerical versus graphical aids for decision-making in a multi-cue signal identification task

Decision aids are commonly used in tactical decision-making environments to help humans integrate base-rate and multi-cue information. However, it is important that users appropriately trust and rely on aids. Decision aids can be presented in many ways, but the literature lacks clarity over the conditions surrounding their effectiveness. This research aims to determine whether a numerical or graphical aid more effectively supports human performance, and explores the relationships between aid presentation, trust, and workload. Participants (N = 30) completed a signal-identification task that required integration of readings from a set of three dynamic gauges. Participants experienced three conditions: unaided, using a numerical aid, and using a graphical aid. The aids combined gauge and base-rate information in a statistically-optimal fashion. Participants also indicated how much they trusted the system and how hard they worked during the task. Analyses explored the impact of aid condition on sensitivity, response bias, response time, trust, and workload. Both the numerical and graphical aids produced significant increases in sensitivity and trust, and significant decreases in workload in comparison to the unaided condition. The difference in response time between the graphical and unaided conditions approached significance, with participants responding faster using the graphical aid without decrements in sensitivity. Significant interactions between aid and signal type indicated that both aided conditions promoted faster responding to non-hostile signals, with larger mean differences in the graphical aid condition. Practically, graphical aids in which suggestions are more salient to users may promote faster responding in tactical environments, with negligible cost of accuracy.

The Lure of Beauty: People Select Representations of Statistical Information Largely Based on Attractiveness, Not Comprehensibility

OBJECTIVE

People differ in whether they understand graphical or numerical representations of statistical information better. However, assessing these skills is often not feasible when deciding which representation to select or use. This study investigates whether people choose the representation they understand better, whether this choice can improve risk comprehension, and whether results are influenced by participants' skills (graph literacy and numeracy).

METHODS

In an experiment, 160 participants received information about the benefits and side effects of painkillers using either a numerical or a graphical representation. In the "no choice" condition, the representation was randomly assigned to each participant. In the "choice" condition, participants could select the representation they would like to receive. The study assessed gist and verbatim knowledge (immediate comprehension and recall), accessibility of the information, attractiveness of the representation, as well as graph literacy and numeracy.

RESULTS

In the "choice" condition, most (62.5%) chose the graphical format, yet there was no difference in graph literacy or numeracy (nor age or gender) between people who chose the graphical or the numerical format. Whereas choice slightly increased verbatim knowledge, it did not improve gist or overall knowledge compared with random assignment. However, participants who chose a representation rated the representation as more attractive, and those who chose graphs rated them as more accessible than those without a choice.

LIMITATIONS

The sample consisted of highly educated undergraduate students with higher graph literacy than the general population. The task was inconsequential for participants in terms of their health.

CONCLUSIONS

When people can choose between representations, they fail to identify what they comprehend better but largely base that choice on how attractive the representation is for them.

HIGHLIGHTS

People differ systematically in whether they understand graphical or numerical representations of statistical information better. However, assessing these underlying skills to get the right representation to the right people is not feasible in practice. A simple and efficient method to achieve this could be to let people choose among representations themselves.However, our study showed that allowing participants to choose a representation (numerical v. graphical) did not improve overall or gist knowledge compared with determining the representation randomly, even though it did slightly improve verbatim knowledge.Rather, participants largely chose the representation they found more attractive. Most preferred the graphical representation, including those with low graph literacy.It would therefore be important to develop graphical representations that are not only attractive but also comprehensible even for people with low graph literacy.

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).

Examining Effort in 1D Uncertainty Communication Using Individual Differences in Working Memory and NASA-TLX

As uncertainty visualizations for general audiences become increasingly common, designers must understand the full impact of uncertainty communication techniques on viewers' decision processes. Prior work demonstrates mixed performance outcomes with respect to how individuals make decisions using various visual and textual depictions of uncertainty. Part of the inconsistency across findings may be due to an over-reliance on task accuracy, which cannot, on its own, provide a comprehensive understanding of how uncertainty visualization techniques support reasoning processes. In this work, we advance the debate surrounding the efficacy of modern 1D uncertainty visualizations by conducting converging quantitative and qualitative analyses of both the effort and strategies used by individuals when provided with quantile dotplots, density plots, interval plots, mean plots, and textual descriptions of uncertainty. We utilize two approaches for examining effort across uncertainty communication techniques: a measure of individual differences in working-memory capacity known as an operation span (OSPAN) task and self-reports of perceived workload via the NASA-TLX. The results reveal that both visualization methods and working-memory capacity impact participants' decisions. Specifically, quantile dotplots and density plots (i.e., distributional annotations) result in more accurate judgments than interval plots, textual descriptions of uncertainty, and mean plots (i.e., summary annotations). Additionally, participants' open-ended responses suggest that individuals viewing distributional annotations are more likely to employ a strategy that explicitly incorporates uncertainty into their judgments than those viewing summary annotations. When comparing quantile dotplots to density plots, this work finds that both methods are equally effective for low-working-memory individuals. However, for individuals with high-working-memory capacity, quantile dotplots evoke more accurate responses with less perceived effort. Given these results, we advocate for the inclusion of converging behavioral and subjective workload metrics in addition to accuracy performance to further disambiguate meaningful differences among visualization techniques.

The Science of Visual Data Communication: What Works

Effectively designed data visualizations allow viewers to use their powerful visual systems to understand patterns in data across science, education, health, and public policy. But ineffectively designed visualizations can cause confusion, misunderstanding, or even distrust-especially among viewers with low graphical literacy. We review research-backed guidelines for creating effective and intuitive visualizations oriented toward communicating data to students, coworkers, and the general public. We describe how the visual system can quickly extract broad statistics from a display, whereas poorly designed displays can lead to misperceptions and illusions. Extracting global statistics is fast, but comparing between subsets of values is slow. Effective graphics avoid taxing working memory, guide attention, and respect familiar conventions. Data visualizations can play a critical role in teaching and communication, provided that designers tailor those visualizations to their audience.

Communicating Uncertainties About the Effects of Medical Interventions Using Different Display Formats

Communicating uncertainties in scientific evidence is important to accurately reflect scientific knowledge , increase public understanding of uncertainty, and to signal transparency and honesty in reporting. While techniques have been developed to facilitate the communication of uncertainty, many have not been empirically tested, compared for communicating different types of uncertainty, or their effects on different cognitive, trust, and behavioral outcomes have not been evaluated. The present study examined how a point estimate, imprecise estimate, conflicting estimates, or a statement about the lack of evidence about treatment effects, influenced participant's responses to communications about medical evidence. For each type of uncertainty, we adapted three display formats to communicate the information: tables, bar graphs, and icon arrays. We compared participant's best estimates of treatment effects, as well as effects on recall, subjective evaluations (understandability and usefuleness), certainty perceptions, perceptions of trustworthiness of the information, and behavioral intentions. We did not find any detrimental effects from communicating imprecision or conflicting estimates relative to a point estimate across any outcome. Furthermore, there were more favorable responses to communicating imprecision or conflicting estimates relative to lack of evidence, where participants estimated the treatment would improve outcomes by 30-50% relative to a placebo. There were no differences across display formats, suggesting that, if well-designed, it may not matter which format is used. Future research on specific display formats or uncertainty types and with larger sample sizes would be needed to detect small effects. Implications for the communication of uncertainty are discussed.

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

BACKGROUND

Few studies have examined the best way to convey the probability of serious events occurring in the future (i.e., risk of stroke or death) to persons with low numeracy or graph literacy proficiency. To address this gap, we developed and user-tested a bar graph and compared it to icon arrays to assess its impact on understanding and preference for viewing risk information.

OBJECTIVES

To determine the: (i) formats' impact on participants' understanding of risk information; (ii) formats' impact on understanding and format preference across numeracy and graph literacy subgroups; (iii) rationale supporting participants' preference for each graphical display format.

METHODS

An online sample (evenly made up of participants with high and low objective numeracy and graph literacy) was randomized to view either the icon array or the bar graph. Each format conveyed the risk of major stroke and death five years after choosing surgery, a stent, or medication to treat carotid artery stenosis. Participants answered questions to assess their understanding of the risk information. Lastly, both formats were presented in parallel, and participants were asked to identify their preferred format to view risk information and explain their preference.

RESULTS

Of the 407 participants, 197 were assigned the icon array and 210 the bar graph. Understanding of risk information and format preference did not differ significantly between the two trial arms, irrespective of numeracy and graph literacy proficiency. High numeracy and graph literacy proficiency was associated with high understanding (p<0.01) and a preference for the bar graph (p = 0.01).

CONCLUSION

We found no evidence to demonstrate the superiority of one format over another on understanding. The majority of participants preferred viewing the risk information using the bar graph format.

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

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.

Regional anaesthesia: risk, consent and complications

The risks of regional anaesthesia relate primarily to the technical nature of the procedure, chief among them being neurological. While rare, the direct relationship between nerve damage and the procedure itself means that patients need to be aware of this complication when consent is sought. In order to give valid consent, a patient must be informed. The extent of the information required has been defined by a 2015 legal ruling which established that the standard is the expectation of a reasonable patient, rather than the information deemed consequential by a reasonable doctor. The implications of this for clinicians are profound, and mean that the process of consent must, for example, include alternatives to the proposed treatment. Additionally, patients must have capacity and give their consent without coercion. Effective communication of risk can be challenging. As well as the barriers to comprehension that can result from language, literacy and numeracy, clinicians need to be aware of their own biases, often in favour of a regional anaesthetic approach. Patients also have biases, and doctors must be aware of these in order to best target their provision of information. Careful use of language and employing adjuncts such as information leaflets and visual aids can help to maximise the individual's autonomy. Particular care must be taken in special situations such as where patients have capacity issues or time is limited by the emergency nature of the intervention.

The Precision-Bias Distinction for Evaluating Visual Decision Aids for Risk Perception

Risk communication is critically important, for both patients and providers. However, people struggle to understand risks because there are inherent biases and limitations to reasoning under uncertainty. A common strategy to enhance risk communication is the use of decision aids, such as charts or graphs, that depict the risk visually. A problem with prior research on visual decision aids is that it used a metric of performance that confounds 2 underlying constructs: precision and bias. Precision refers to a person's sensitivity to the information, whereas bias refers to a general tendency to overestimate (or underestimate) the level of risk. A visual aid is effective for communicating risk only if it enhances precision or, once precision is suitably high, reduces bias. This article proposes a methodology for evaluating the effectiveness of visual decision aids. Empirical data further illustrate how the new methodology is a significant advancement over more traditional research designs.

Giving Voice to Parents in the Development of the Preemie Prep for Parents (P3) Mobile App

BACKGROUND

Parents at risk for preterm birth frequently receive prematurity education when the mother is hospitalized for premature labor. Parental ability to learn and consider the information is limited because of the stress of the hospitalization. A promising approach is dissemination of information to at-risk parents before the birth hospitalization.

PURPOSE

This article describes formative research used to develop smartphone-based prematurity education app for parents at-risk for preterm birth.

METHODS

Stakeholders were parents with a prior preterm birth. Using stakeholder meeting transcripts, constant comparative analysis was used to reflect upon the parental voice.

RESULTS

The parents named the app, Preemie Prep for Parents (P3). Parent perspectives revealed desire for information in the following 5 categories. (1) Power in knowledge and control: parents want autonomy when learning information that may influence medical decision-making. (2) Content and framing of information: they desire information from a trusted resource that helps promote prenatal health and provides neonatal intensive care information. (3) Displaying content: parents want personalization, push notifications, photographs displaying fetal development, and easy-to-understand statistics. (4) Providing information without causing harm: they desire non-value-laden information, and they do not support "gamifying" the app to enhance utilization. (5) Decision making: parents want information that would benefit their decision making without assuming that parents have a certain outlook on life or particular values.

IMPLICATIONS FOR PRACTICE

These findings support the need for the P3 App to aid in decision making when parents experience preterm birth.

IMPLICATIONS FOR RESEARCH

The findings highlight the need to study the effects of smartphone-based prematurity education on medical decision-making.

Do risk visualizations improve the understanding of numerical risks? A randomized, investigator-blinded general population survey

BACKGROUND

Risk visualizations are often employed to support risk communication. However, their effectiveness in communication of single absolute risks remains unclear. We investigated the effectiveness of risk visualizations in conveying verbatim knowledge of single absolute risks among the general population.

METHODS

Randomly sampled members of the general Dutch population completed four basic risk conversions from percentages to natural frequencies and vice versa. By random investigator-blinded allocation, these conversions were supported by either icon arrays, pie charts, bar graphs or no visualization. Verbatim risk knowledge was scored as the number of conversions completed correctly.

RESULTS

393 subjects were included. Overall, 60% of respondents answered all four questions correctly. Risk format (percentages vs. natural frequencies, p = 0.677) and risk magnitude (p = 0.532) were not associated with verbatim risk knowledge score. Younger age (p = 0.001) and higher education level (p < 0.001) were independently associated with higher scores. The use of risk visualizations was not associated with higher scores (OR = 1.08; 95% confidence interval: 0.69-1.69; p = 0.745). All three forms of risk visualization were equally ineffective. These findings held when stratifying by risk format, risk magnitude and user preference for a certain form of risk visualization. There were no significant interactions with age or education level.

CONCLUSION

Risk visualizations did not improve conveyance of verbatim knowledge of single absolute risks, irrespective of age, education level, risk magnitude, risk format and form of risk visualization. Risk visualizations may therefore be less suitable for settings in which detailed conveyance of single absolute risks is the main objective, although their effect on user experience and perception of risk communication and subsequent patient activation and participation remains to be elucidated.

Prosthetists' perceptions of information obtained from a lower limb prosthesis monitoring system: a pilot study

Introduction

Prosthetists have limited knowledge of their patients' use of a prosthesis outside of the clinical environment. Prosthesis-mounted monitors can be used to directly measure patients' prosthesis use and activity. Prosthetists' opinions regarding potential clinical applications for sensor-based information may inform further development of this technology. A pilot study was conducted to assess prosthetists' perceptions of prosthesis use and activity information obtained by a monitoring system.

Materials and methods

Three local prosthetists were recruited to participate in the study. One patient with transtibial amputation from each prosthetist volunteered to wear limb presence and activity monitors for two weeks. Collected data were used to determine prosthesis use and activity. Each prosthetist completed a survey, examined clinical reports of their patient's prosthesis use and activity, and participated in a semi-structured interview. Survey results and interview transcripts were analyzed to identify and compare prosthetists' perceptions.

Results

Prosthesis use and activity varied among patients. Prosthetists over- and under-estimated patient activity, relative to measurements recorded by the monitors. All three prosthetists selected multiple clinical applications for the prosthesis use and activity information in the survey, and several additional applications were suggested during the interviews. When presented with multiple report formats, prosthetists found features of each to be clinically useful.

Conclusions

Prosthesis-mounted monitors may provide prosthetists with a better understanding of their patients' prosthesis use and activity. Information provided by the monitoring system may inform clinical decisions and promote evidence-based practices.

Presenting time-based risks of stroke and death for Patients facing carotid stenosis treatment options: Patients prefer pie charts over icon arrays

OBJECTIVE

To user-test graphical display formats (icon arrays, pie, bar, and line charts) to identify preferred formats and metrics ('probability of death or stroke' or 'proportion of time lived without death or stroke') in order to display time-dependent risks of stroke or death for three carotid stenosis treatments: endarterectomy (surgery), stenting, and medical therapy.

METHODS

Iterative cycles of semi-structured interviews with patients recruited from a Vascular Clinic.

RESULTS

A total of 27 patients (mean age = 68; range: 50-85) were interviewed over four cycles. Patients strongly preferred the pie chart over icon arrays, and over bar or line graphs. The preference was based on patient recognition of the time-based increase in risk for stroke or death for treatment options. Patients preferred data presented as probabilities instead of the proportion of time lived. We did not assess patients' understanding.

CONCLUSION

Patients preferred the pie chart formats and reported better realization that risks increase with time for each option and that tradeoffs exist when surgery has a higher short-term risk than medical therapy.

PRACTICE IMPLICATIONS

There remains debate on how best to convey time-dependent risk information to patients, especially where low literacy and numeracy might exist.

A global, incremental development method for a web-based prostate cancer treatment decision aid and usability testing in a Dutch clinical setting

Many new decision aids are developed while aspects of existing decision aids could also be useful, leading to a sub-optimal use of resources. To support treatment decision-making in prostate cancer patients, a pre-existing evidence-based Canadian decision aid was adjusted to Dutch clinical setting. After analyses of the original decision aid and routines in Dutch prostate cancer care, adjustments to the decision aid structure and content were made. Subsequent usability testing (N = 11) resulted in 212 comments. Care providers mainly provided feedback on medical content, and patients commented most on usability and summary layout. All participants reported that the decision aid was comprehensible and well-structured and would recommend decision aid use. After usability testing, final adjustments to the decision aid were made. The presented methods could be useful for cultural adaptation of pre-existing tools into other languages and settings, ensuring optimal usage of previous scientific and practical efforts and allowing for a global, incremental decision aid development process.

Aiding Risk Information learning through Simulated Experience (ARISE): A Comparison of the Communication of Screening Test Information in Explicit and Simulated Experience Formats

OBJECTIVE

To determine whether the use of Aiding Risk Information learning through Simulated Experience (ARISE) to communicate conditional probabilities about maternal serum screening results for Down syndrome promotes more accurate positive predictive value (PPV) estimates and conceptual understanding of screening, compared with explicitly providing individuals with this information via numerical summary or icon array.

METHOD

In experiment 1, 582 participants completed an online study in which they were asked to estimate the PPV and rate their attitudes toward a screening test when information was presented in either a description (required calculation of the PPV), explicit (PPV was provided and had to be identified), or an ARISE format (PPV was inferred through experience-based learning). In experiment 2, 316 participants estimated the PPV and rated their attitudes toward screening based on information presented in either an icon array (identify the icons that represent the PPV) or ARISE format.

RESULTS

In experiment 1, ARISE elicited the most accurate PPV estimates compared with the description and explicit formats, and both the explicit and ARISE formats led to more unfavorable attitudes toward screening. In experiment 2, both the icon array and ARISE resulted in similar PPV estimates; however, ARISE led to more negative attitudes toward screening.

CONCLUSIONS

These findings suggest that ARISE may be superior to other formats in the communication of PPV information for screening tests. However, differences in the complexity of the formats vary and require further investigation.

In proportion: approaches for displaying patient-reported outcome research study results as percentages responding to treatment

PURPOSE

Patient-reported outcome (PRO) data from clinical trials can promote valuable patient-clinician communication and aid the decision-making process regarding treatment options. Despite these benefits, both patients and doctors face challenges in interpreting PRO scores. The purpose of this study was to identify best practices for presenting PRO results expressed as proportions of patients with changes from baseline (improved/stable/worsened) for use in patient educational materials and decision aids.

METHODS

We electronically surveyed adult cancer patients/survivors, oncology clinicians, and PRO researchers, and conducted one-on-one cognitive interviews with patients/survivors and clinicians. Participants saw clinical trial data comparing two treatments as proportions changed using three different formats: pie charts, bar graphs, icon arrays. Interpretation accuracy, clarity, and format preference were analyzed quantitatively and online survey comments and interviews, qualitatively.

RESULTS

The internet sample included 629 patients, 139 clinicians, and 249 researchers; 10 patients and 5 clinicians completed interviews. Bar graphs were less accurately interpreted than pie charts (OR 0.39; p < .0001) and icon arrays (OR 0.47; p < .0001). Bar graphs and icon arrays were less likely to be rated clear than pie charts (OR 0.37 and OR 0.18; both p < .0001). Qualitative data informed interpretation of these findings.

CONCLUSIONS

For communicating PROs as proportions changed in patient educational materials and decision aids, these results support the use of pie charts.

A Web-Based Treatment Decision Support Tool for Patients With Advanced Knee Arthritis: Evaluation of User Interface and Content Design

Background

Data-driven surgical decisions will ensure proper use and timing of surgical care. We developed a Web-based patient-centered treatment decision and assessment tool to guide treatment decisions among patients with advanced knee osteoarthritis who are considering total knee replacement surgery.

Objective

The aim of this study was to examine user experience and acceptance of the Web-based treatment decision support tool among older adults.

Methods

User-centered formative and summative evaluations were conducted for the tool. A sample of 28 patients who were considering total knee replacement participated in the study. Participants’ responses to the user interface design, the clarity of information, as well as usefulness, satisfaction, and acceptance of the tool were collected through qualitative (ie, individual patient interviews) and quantitative (ie, standardized Computer System Usability Questionnaire) methods.

Results

Participants were older adults with a mean age of 63 (SD 11) years. Three-quarters of them had no technical questions using the tool. User interface design recommendations included larger fonts, bigger buttons, less colors, simpler navigation without extra “next page” click, less mouse movement, and clearer illustrations with simple graphs. Color-coded bar charts and outcome-specific graphs with positive action were easiest for them to understand the outcomes data. Questionnaire data revealed high satisfaction with the tool usefulness and interface quality, and also showed ease of use of the tool, regardless of age or educational status.

Conclusions

We evaluated the usability of a patient-centered decision support tool designed for advanced knee arthritis patients to facilitate their knee osteoarthritis treatment decision making. The lessons learned can inform other decision support tools to improve interface and content design for older patients’ use.

Communicating projected survival with treatments for chronic kidney disease: patient comprehension and perspectives on visual aids

BACKGROUND

Mortality in end stage renal disease (ESRD) is higher than many malignancies. There is no data about the optimal way to present information about projected survival to patients with ESRD. In other areas, graphs have been shown to be more easily understood than narrative. We examined patient comprehension and perspectives on graphs in communicating projected survival in chronic kidney disease (CKD).

METHODS

One hundred seventy-seven patients with CKD were shown 4 different graphs presenting post transplantation survival data. Patients were asked to interpret a Kaplan Meier curve, pie chart, histogram and pictograph and answer a multi-choice question to determine understanding.

RESULTS

We measured interpretation, usefulness and preference for the graphs. Most patients correctly interpreted the graphs. There was asignificant difference in the percentage of correct answers when comparing different graph types (p = 0.0439). The pictograph was correctly interpreted by 81% of participants, the histogram by 79%, pie chart by 77% and Kaplan Meier by 69%. Correct interpretation of the histogram was associated with educational level (p = 0.008) and inversely associated with age > 65 (p = 0.008). Of those who interpreted all four graphs correctly, there was an association with employment (p = 0.001) and New Zealand European ethnicity (p = 0.002). 87% of patients found the graphs useful. The pie chart was the most preferred graph (p 0.002). The readability of the graphs may have been improved with an alternative colour choice, especially in the setting of visual impairment.

CONCLUSION

Visual aids, can be beneficial adjuncts to discussing survival in CKD.

Designing Visual Aids That Promote Risk Literacy: A Systematic Review of Health Research and Evidence-Based Design Heuristics

Background Effective risk communication is essential for informed decision making. Unfortunately, many people struggle to understand typical risk communications because they lack essential decision-making skills. Objective The aim of this study was to review the literature on the effect of numeracy on risk literacy, decision making, and health outcomes, and to evaluate the benefits of visual aids in risk communication. Method We present a conceptual framework describing the influence of numeracy on risk literacy, decision making, and health outcomes, followed by a systematic review of the benefits of visual aids in risk communication for people with different levels of numeracy and graph literacy. The systematic review covers scientific research published between January 1995 and April 2016, drawn from the following databases: Web of Science, PubMed, PsycINFO, ERIC, Medline, and Google Scholar. Inclusion criteria were investigation of the effect of numeracy and/or graph literacy, and investigation of the effect of visual aids or comparison of their effect with that of numerical information. Thirty-six publications met the criteria, providing data on 27,885 diverse participants from 60 countries. Results Transparent visual aids robustly improved risk understanding in diverse individuals by encouraging thorough deliberation, enhancing cognitive self-assessment, and reducing conceptual biases in memory. Improvements in risk understanding consistently produced beneficial changes in attitudes, behavioral intentions, trust, and healthy behaviors. Visual aids were found to be particularly beneficial for vulnerable and less skilled individuals. Conclusion Well-designed visual aids tend to be highly effective tools for improving informed decision making among diverse decision makers. We identify five categories of practical, evidence-based guidelines for heuristic evaluation and design of effective visual aids.

Does Iconicity in Pictographs Matter? The Influence of Iconicity and Numeracy on Information Processing, Decision Making, and Liking in an Eye-Tracking Study

Researchers recommend the use of pictographs in medical risk communication to improve people's risk comprehension and decision making. However, it is not yet clear whether the iconicity used in pictographs to convey risk information influences individuals' information processing and comprehension. In an eye-tracking experiment with participants from the general population (N = 188), we examined whether specific types of pictograph icons influence the processing strategy viewers use to extract numerical information. In addition, we examined the effect of iconicity and numeracy on probability estimation, recall, and icon liking. This experiment used a 2 (iconicity: blocks vs. restroom icons) × 2 (scenario: medical vs. nonmedical) between-subject design. Numeracy had a significant effect on information processing strategy, but we found no effect of iconicity or scenario. Results indicated that both icon types enabled high and low numerates to use their default way of processing and extracting the gist of the message from the pictorial risk communication format: high numerates counted icons, whereas low numerates used large-area processing. There was no effect of iconicity in the probability estimation. However, people who saw restroom icons had a higher probability of correctly recalling the exact risk level. Iconicity had no effect on icon liking. Although the effects are small, our findings suggest that person-like restroom icons in pictographs seem to have some advantages for risk communication. Specifically, in nonpersonalized prevention brochures, person-like restroom icons may maintain reader motivation for processing the risk information.

Visualization approaches to support healthy aging: A systematic review

Background

Informatics tools have the potential to support the growing number of older adults who are aging in place. Many tools include visualizations (data visualizations and visualizations of physical representations). However, the role of visualizations in supporting aging in place remains largely unexplored.

Objective

To synthesize and identify gaps in the literature evaluating visualizations (data visualizations and visualizations of physical representations) for informatics tools to support healthy aging.

Methods

We conducted a search in CINAHL, Embase, Engineering Village, PsycINFO, PubMed, and Web of Science using a priori defined terms for publications in English describing community-based studies evaluating visualizations used by adults aged ≥ 65 years.

Results

Six out of the identified 251 publications were eligible. Most studies described in the publications were user studies and all varied methodological quality. Three publications described visualizations of virtual representations supported performing at-home exercises. Participants found visual representations either (1) helpful, motivational, and supported their understanding of their health behaviours or (2) not an improvement over alternatives. Three publications described data visualizations that aimed to support understanding of one’s health. Participants were able to interpret data visualizations that used precise data and encodings that were more concrete better than those that did not provide precision or were abstract. Participants found data visualizations helpful in understanding their overall health and granular data.

Conclusions

Few studies were identified that used and evaluated visualizations for older adults to promote engagement in exercises or understanding of their health. While visualizations demonstrated some promise to support older adult users in these activities, the studies had various methodological limitations. More research is needed, including research that overcomes methodological limitations of studies we identified, to develop visualizations that older adults could use with ease and accuracy to support their health behaviours and decision making.

High Numerates Count Icons and Low Numerates Process Large Areas in Pictographs: Results of an Eye-Tracking Study

In two experiments, we investigated the influence of numeracy on individuals' information processing of pictographs depending on numeracy via an eye-tracker. In two conditions, participants from the general population were presented with a scenario depicting the risk of having cancer and were asked to indicate their perceived risk. The risk level was high (63%) in experiment 1 (N = 70) and low (6%) in experiment 2 (N = 69). In the default condition, participants were free to use their default strategy for information processing. In the guiding-toward-the-number condition, they were prompted to count icons in the pictograph by answering with an explicit number. We used eye-tracking parameters related to the distance between sequential fixations to analyze participants' strategies for processing numerical information. In the default condition, the higher the numeracy was, the shorter the distances traversed in the pictograph were, indicating that participants counted the icons. People lower in numeracy performed increased large-area processing by comparing highlighted and nonhighlighted parts of the pictograph. In the guiding-toward-the-number condition, participants used short distances regardless of their numeracy, supporting the notion that short distances represent counting. Despite the different default processing strategies, participants processed the pictograph with a similar depth and derived similar risk perceptions. The results show that pictographs are beneficial for communicating medical risk. Pictographs make the gist salient by making the part-to-whole relationship visually available, and they facilitate low numerates' non-numeric processing of numerical information. Contemporaneously, pictographs allow high numerates to numerically process and rely on the number depicted in the pictograph.

Improving risk literacy in surgeons

OBJECTIVE

To effectively practice evidence-based medicine, surgeons need to understand and be able to communicate health-relevant numerical information. We present the first study examining risk literacy in surgeons by assessing numeracy and surgical risk comprehension. Our study also investigated whether visual aids improve risk comprehension in surgeons with limited numeracy.

METHODS

Participants were 292 surgeons from 60 countries who completed an instrument measuring numeracy and evaluated the results of a randomized controlled trial including post-surgical side-effects. Half of the surgeons received this information in numbers. The other half received the information represented visually. Accuracy of risk estimation, reading latency, and estimate latency (i.e., deliberation) were assessed.

RESULTS

Some surgeons have low numeracy and could not correctly interpret surgical risks without additional support. Visual aids made risks transparent and eliminated differences in risk understanding between more and less numerate surgeons, increasing the amount of time that less numerate surgeons spent deliberating about risks.

CONCLUSIONS

Visual aids can be an efficient and inexpensive means of improving risk comprehension and clinical judgement in surgeons with low numerical and statistical skills.

PRACTICE IMPLICATIONS

Programs designed to help professionals represent and communicate health-relevant numerical information in simple transparent graphs may unobtrusively promote informed decision making.

Visual presentations of efficacy data in direct-to-consumer prescription drug print and television advertisements: A randomized study

OBJECTIVE

To determine whether visual aids help people recall quantitative efficacy information in direct-to-consumer (DTC) prescription drug advertisements, and if so, which types of visual aids are most helpful.

METHODS

Individuals diagnosed with high cholesterol (n=2504) were randomized to view a fictional DTC print or television advertisement with no visual aid or one of four visual aids (pie chart, bar chart, table, or pictograph) depicting drug efficacy. We measured drug efficacy and risk recall, drug perceptions and attitudes, and behavioral intentions.

RESULTS

For print advertisements, a bar chart or table, compared with no visual aid, elicited more accurate drug efficacy recall. The bar chart was better at this than the pictograph and the table was better than the pie chart. For television advertisements, any visual aid, compared with no visual aid, elicited more accurate drug efficacy recall. The bar chart was better at this than the pictograph or the table.

CONCLUSION

Visual aids depicting quantitative efficacy information in DTC print and television advertisements increased drug efficacy recall, which may help people make informed decisions about prescription drugs.

PRACTICE IMPLICATIONS

Adding visual aids to DTC advertising may increase the public's knowledge of how well prescription drugs work.

Approaches for describing and communicating overall uncertainty in toxicity characterizations: U.S. Environmental Protection Agency's Integrated Risk Information System (IRIS) as a case study

Single point estimates of human health hazard/toxicity values such as a reference dose (RfD) are generally used in chemical hazard and risk assessment programs for assessing potential risks associated with site- or use-specific exposures. The resulting point estimates are often used by risk managers for regulatory decision-making, including standard setting, determination of emission controls, and mitigation of exposures to chemical substances. Risk managers, as well as stakeholders (interested and affected parties), often have limited information regarding assumptions and uncertainty factors in numerical estimates of both hazards and risks. Further, the use of different approaches for addressing uncertainty, which vary in transparency, can lead to a lack of confidence in the scientific underpinning of regulatory decision-making. The overarching goal of this paper, which was developed from an invited participant workshop, is to offer five approaches for presenting toxicity values in a transparent manner in order to improve the understanding, consideration, and informed use of uncertainty by risk assessors, risk managers, and stakeholders. The five approaches for improving the presentation and communication of uncertainty are described using U.S. Environmental Protection Agency's (EPA's) Integrated Risk Information System (IRIS) as a case study. These approaches will ensure transparency in the documentation, development, and use of toxicity values at EPA, the Agency for Toxic Substances and Disease Registry (ATSDR), and other similar assessment programs in the public and private sector. Further empirical testing will help to inform the approaches that will work best for specific audiences and situations.

Words or graphics to present a Discrete Choice Experiment: Does it matter?

OBJECTIVE

To test whether presenting attribute levels in words or graphics generates different results with respect to attribute level interpretation, relative importance and participation probabilities.

METHODS

Parents of 959 newborns completed a DCE questionnaire that contained two versions of the same nine choice tasks in which the attribute levels were presented in words or graphics. Five attributes related to the decision of parents to vaccinate their newborn against rotavirus were included. Mixed-logit models were conducted to estimate the relative importance of the attribute levels.

RESULTS

Respondents who started with the choice tasks in words produced the most consistent answer patterns. All respondents significantly preferred words to graphics. Part-worth utilities and the relative importance of the attribute levels differed based on the words and graphics data, resulting in different probabilities to participate in vaccination.

CONCLUSIONS

Words were preferred over graphics, resulted in higher choice consistency, and showed more valid attribute level estimates. Graphics did not improve respondents' understanding of the attribute levels.

PRACTICE IMPLICATIONS

Future research on the use of either words or graphics is recommended in order to establish guidelines on how to develop a valid presentation method for attribute levels in the choice tasks of a DCE.

Design and feasibility of integrating personalized PRO dashboards into prostate cancer care

OBJECTIVE

Patient-reported outcomes (PROs) are a valued source of health information, but prior work focuses largely on data capture without guidance on visual displays that promote effective PRO use in patient-centered care. We engaged patients, providers, and design experts in human-centered design of "PRO dashboards" that illustrate trends in health-related quality of life (HRQOL) reported by patients following prostate cancer treatment.

MATERIALS AND METHODS

We designed and assessed the feasibility of integrating dashboards into care in 3 steps: (1) capture PRO needs of patients and providers through focus groups and interviews; (2) iteratively build and refine a prototype dashboard; and (3) pilot test dashboards with patients and their provider during follow-up care.

RESULTS

Focus groups (n = 60 patients) prioritized needs for dashboards that compared longitudinal trends in patients' HRQOL with "men like me." Of the candidate dashboard designs, 50 patients and 50 providers rated pictographs less helpful than bar charts, line graphs, or tables (P < .001) and preferred bar charts and line graphs most. Given these needs and the design recommendations from our Patient Advisory Board (n = 7) and design experts (n = 7), we built and refined a prototype that charts patients' HRQOL compared with age- and treatment-matched patients in personalized dashboards. Pilot testing dashboard use (n = 12 patients) improved compliance with quality indicators for prostate cancer care (P < .01).

CONCLUSION

PRO dashboards are a promising approach for integrating patient-generated data into prostate cancer care. Informed by human-centered design principles, this work establishes guidance on dashboard content, tailoring, and clinical use that patients and providers find meaningful.

Visual aids improve diagnostic inferences and metacognitive judgment calibration

Visual aids can improve comprehension of risks associated with medical treatments, screenings, and lifestyles. Do visual aids also help decision makers accurately assess their risk comprehension? That is, do visual aids help them become well calibrated? To address these questions, we investigated the benefits of visual aids displaying numerical information and measured accuracy of self-assessment of diagnostic inferences (i.e., metacognitive judgment calibration) controlling for individual differences in numeracy. Participants included 108 patients who made diagnostic inferences about three medical tests on the basis of information about the sensitivity and false-positive rate of the tests and disease prevalence. Half of the patients received the information in numbers without a visual aid, while the other half received numbers along with a grid representing the numerical information. In the numerical condition, many patients–especially those with low numeracy–misinterpreted the predictive value of the tests and profoundly overestimated the accuracy of their inferences. Metacognitive judgment calibration mediated the relationship between numeracy and accuracy of diagnostic inferences. In contrast, in the visual aid condition, patients at all levels of numeracy showed high-levels of inferential accuracy and metacognitive judgment calibration. Results indicate that accurate metacognitive assessment may explain the beneficial effects of visual aids and numeracy–a result that accords with theory suggesting that metacognition is an essential part of risk literacy. We conclude that well-designed risk communications can inform patients about healthrelevant numerical information while helping them assess the quality of their own risk comprehension.

Effects of Numerical Versus Foreground-Only Icon Displays on Understanding of Risk Magnitudes

The aim of this work is to advance knowledge of how to measure gist and verbatim understanding of risk magnitude information and to apply this knowledge to address whether graphics that focus on the number of people affected (the numerator of the risk ratio, i.e., the foreground) are effective displays for increasing (a) understanding of absolute and relative risk magnitudes and (b) risk avoidance. In 2 experiments, the authors examined the effects of a graphical display that used icons to represent the foreground information on measures of understanding (Experiments 1 and 2) and on perceived risk, affect, and risk aversion (Experiment 2). Consistent with prior findings, this foreground-only graphical display increased perceived risk and risk aversion; however, it also led to decreased understanding of absolute (although not relative) risk magnitudes. Methodologically, this work shows the importance of distinguishing understanding of absolute risk from understanding of relative risk magnitudes, and the need to assess gist knowledge of both types of risk. Substantively, this work shows that although using foreground-only graphical displays is an appealing risk communication strategy to increase risk aversion, doing so comes at the cost of decreased understanding of absolute risk magnitudes.

Does a decision aid for prostate cancer affect different aspects of decisional regret, assessed with new regret scales? A randomized, controlled trial

OBJECTIVE

To develop and validate new regret scales and examine whether a decision aid affects different aspects of regret in the treatment choice for prostate cancer.

METHODS

This was a multicentre trial (three sites) with imbalanced randomization (1 : 2). From 2008 to 2011, patients with localized prostate cancer were randomized 1 : 2 to usual care (N = 77) or usual care plus a decision aid presenting risks and benefits of different treatments (N = 163). The treatments were surgery and (external or interstitial) radiotherapy. Regret was assessed before, and 6 and 12 months after treatment, using the Decisional regret scale by Brehaut et al. (Medical Decision Making, 23, 2003, 281), and three new scales focusing on process, option and outcome regret. The relation between decision aid and regret was analysed by anova.

RESULTS

The concurrent validity of the new regret scales was confirmed by correlations between regret and anxiety, depression, decision evaluation scales and health-related quality of life. With a decision aid, patient participation was increased (P = 0.002), but regret was not. If anything, in patients with serious morbidity the decision aid resulted in a trend to less option regret and less Brehaut regret (P = 0.075 and P = 0.061, with effect sizes of 0.35 and 0.38, respectively). Exploratory analyses suggest that high-risk patients benefitted most from the decision aid.

CONCLUSION

The new regret scales may be of value in distinguishing separate aspects of regret. In general, regret was not affected by the decision aid. In patients with serious morbidity, a trend to lower option regret with a decision aid was observed.

[Guideline for the Development of Evidence-based Patient Information: insights into the methods and implementation of evidence-based health information]

The "Guideline for the Development of Evidence-based Patient Information" project is a novelty. The aim of this project is to enhance the quality of health information. The development and implementation process is guided by national and international standards. Involvement of health information developers plays an essential role. This article provides an insight into the guideline's underlying methodology, using graphics as an example. In addition, the results of a qualitative study exploring the competencies of health information developers are presented. These results will guide the implementation of the guideline. We conducted systematic literature searches (until June 2014), critical appraisal and descriptive analyses applying GRADE for two selected guideline questions. Out of 3,287 hits 11 RCTs were included in the analysis. The evidence has been rated to be of low to moderate quality. Additional graphics may have a positive effect on cognitive outcomes. However, the relevance of the results is questionable. For graphics, we found some indication that especially pictograms but also bar graphs have a positive effect on cognitive outcomes and meet patients' preferences. In order to prepare for the implementation of the guideline, we conducted a qualitative study to explore the competencies of health information developers using expert interviews. Four telephone interviews were conducted, audio recorded, transcribed and analysed according to Grounded Theory. Six categories were identified: literature search, development of health information, participation of target groups, continuing education and further training of health information developers, cooperation with different institutions, essential competencies. Levels of competencies regarding the methods of evidence-based medicine and evidence-based health information vary considerably and indicate a need for training. These results have informed the development of a training programme that will support the implementation.

The effect of different graphical and numerical likelihood formats on perception of likelihood and choice

BACKGROUND

Quantitative risk information plays an important role in decision making about health. This study focuses on commonly used numerical and graphical formats and examines their effect on perception of different likelihoods and choice preferences.

METHODS

An experimental study was conducted with 192 participants, who evaluated 2 sets of 4 lotteries. Numerical formats to describe likelihood varied systematically between participants (X%, X-in-100, or 1-in-X). The effect of graphic formats (bar charts, icon charts) was assessed as a within-subjects factor. Dependent measures included perceived likelihood, choice preferences about participating in the lottery, and processing times.

RESULTS

Numerical likelihoods presented as 1-in-X were processed fastest and were perceived as conveying larger likelihoods than the X-in-100 and percentages formats (mean response times in seconds: 5.65 v. 7.31 and 6.50; mean rating on a 1-9 scale: 4.38 v. 3.30 and 3.31, respectively). The 1-in-X format also evoked a stronger willingness to participate in a lottery than the 2 other numerical formats. The effect of adding graphs on perceived likelihood was moderated by numerical aptitude. Graphs reduced ratings of perceived likelihood of participants with lower numeracy, while there was no overall effect for participants with higher numeracy.

CONCLUSION

Perception of likelihood differs significantly depending on the numerical format used. The 1-in-X format yields higher perceived likelihoods and it appears to be the easiest format to interpret. Graphs primarily affect perception of likelihood of people with lower numerical aptitude. These effects should be taken into account when discussing medical risks with patients.

Improving bone mineral density reporting to patients with an illustration of personal fracture risk

Background

To determine patients’ preferences for, and understanding of, FRAX® fracture risk conveyed through illustrations.

Methods

Drawing on examples from published studies, four illustrations of fracture risk were designed and tested for patient preference, ease of understanding, and perceived risk. We enrolled a convenience sample of adults aged 50 and older at two medical clinics located in the Midwestern and Southern United States. In-person structured interviews were conducted to elicit patient ranking of preference, ease of understanding, and perceived risk for each illustration.

Results

Most subjects (n = 142) were female (64%), Caucasian (76%) and college educated (78%). Of the four risk depictions, a plurality of participants (37%) listed a bar graph as most preferred. Subjects felt this illustration used the stoplight color system to display risk levels well and was the most “clear,” “clean,” and “easy to read”. The majority of subjects (52%) rated the pictogram as the most difficult to understand as this format does not allow people to quickly ascertain their individual risk category.

Conclusions

Communicating risk to patients with illustrations can be done effectively with clearly designed illustrations responsive to patient preference.

Trial Registration

ClinicalTrials.gov Identifier: NCT01507662

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.

The pros and cons of funnel plots as an aid to risk communication and patient decision making

Funnel plots, which simultaneously display a sample statistic and the corresponding sample size for multiple cases, have a range of applications. In medicine, they are used to display treatment outcome rates and caseload volume by institution, which can inform strategic decisions about health care delivery. We investigated lay people's understanding of such plots and explored their suitability as an aid to individual treatment decisions. In two studies, 172 participants answered objective questions about funnel plots representing the surgical outcomes (survival or mortality rates) of institutions varying in caseload, and indicated their preferred institutions. Accuracy for extracting objective information was high, unless question phrasing was inconsistent with the plot's survival/mortality framing, or participants had low numeracy levels. Participants integrated caseload-volume and outcome-rate data when forming preferences, but were influenced by reference lines on the plot to make inappropriate discriminations between institutions with similar outcome rates. With careful choice of accompanying language, funnel plots can be readily understood and are therefore a useful tool for communicating risk. However, they are less effective as a decision aid for individual patient's treatment decisions, and we recommend refinements to the standard presentation of the plots if they are to be used for that purpose.

User-centered design of quality of life reports for clinical care of patients with prostate cancer

BACKGROUND

Primary treatment of localized prostate cancer can result in bothersome urinary, sexual, and bowel symptoms. Yet clinical application of health-related quality-of-life (HRQOL) questionnaires is rare. We employed user-centered design to develop graphic dashboards of questionnaire responses from patients with prostate cancer to facilitate clinical integration of HRQOL measurement.

METHODS

We interviewed 50 prostate cancer patients and 50 providers, assessed literacy with validated instruments (Rapid Estimate of Adult Literacy in Medicine short form, Subjective Numeracy Scale, Graphical Literacy Scale), and presented participants with prototype dashboards that display prostate cancer-specific HRQOL with graphic elements derived from patient focus groups. We assessed dashboard comprehension and preferences in table, bar, line, and pictograph formats with patient scores contextualized with HRQOL scores of similar patients serving as a comparison group.

RESULTS

Health literacy (mean score, 6.8/7) and numeracy (mean score, 4.5/6) of patient participants was high. Patients favored the bar chart (mean rank, 1.8 [P = .12] vs line graph [P < .01] vs table and pictograph); providers demonstrated similar preference for table, bar, and line formats (ranked first by 30%, 34%, and 34% of providers, respectively). Providers expressed unsolicited concerns over presentation of comparison group scores (n = 19; 38%) and impact on clinic efficiency (n = 16; 32%).

CONCLUSION

Based on preferences of prostate cancer patients and providers, we developed the design concept of a dynamic HRQOL dashboard that permits a base patient-centered report in bar chart format that can be toggled to other formats and include error bars that frame comparison group scores. Inclusion of lower literacy patients may yield different preferences.

Blocks, ovals, or people? Icon type affects risk perceptions and recall of pictographs

BACKGROUND

Research has demonstrated that icon arrays (also called "pictographs") are an effective method of communicating risk statistics and appear particularly useful to less numerate and less graphically literate people. Yet research is very limited regarding whether icon type affects how people interpret and remember these graphs.

METHODS

1502 people age 35-75 from a demographically diverse online panel completed a cardiovascular risk calculator based on Framingham data using their actual age, weight, and other health data. Participants received their risk estimate in an icon array graphic that used 1 of 6 types of icons: rectangular blocks, filled ovals, smile/frown faces, an outline of a person's head and shoulders, male/female "restroom" person icons (gender matched), or actual head-and-shoulder photographs of people of varied races (gender matched). In each icon array, blue icons represented cardiovascular events and gray icons represented those who would not experience an event. We measured perceived risk magnitude, approximate recall, and opinions about the icon arrays, as well as subjective numeracy and an abbreviated measure of graphical literacy.

RESULTS

Risk recall was significantly higher with more anthropomorphic icons (restroom icons, head outlines, and photos) than with other icon types, and participants rated restroom icons as most preferred. However, while restroom icons resulted in the highest correlations between perceived and actual risk among more numerate/graphically literate participants, they performed no better than other icon types among less numerate/graphically literate participants.

CONCLUSIONS

Icon type influences both risk perceptions and risk recall, with restroom icons in particular resulting in improved outcomes. However, optimal icon types may depend on numeracy and/or graphical literacy skills.

Communicating Numerical Risk: Human Factors That Aid Understanding in Health Care

In this chapter, we review evidence from the human factors literature that verbal and visual formats can help increase the understanding of numerical risk information in health care. These visual representations of risk are grounded in empirically supported theory. As background, we first review research showing that people often have difficulty understanding numerical risks and benefits in health information. In particular, we discuss how understanding the meanings of numbers results in healthier decisions. Then, we discuss the processes that determine how communication of numerical risks can enhance (or degrade) health judgments and decisions. Specifically, we examine two different approaches to risk communication: a traditional approach and fuzzy-trace theory. Applying research on the complications of understanding and communicating risks, we then highlight how different visual representations are best suited to communicating different risk messages (i.e., their gist). In particular, we review verbal and visual messages that highlight gist representations that can better communicate health information and improve informed decision making. This discussion is informed by human factors theories and methods, which involve the study of how to maximize the interaction between humans and the tools they use. Finally, we present implications and recommendations for future research on human factors in health care.

Communicating Health Risks With Visual Aids

Informed decision making requires that people understand health risks. Unfortunately, many people are not risk literate and are biased by common risk communication practices. In this article, we review a collection of studies investigating the benefits of visual aids for communicating health risks to diverse vulnerable people (e.g., varying in abilities, ages, risk characteristics, and cultural backgrounds). These studies show that appropriately designed visual aids are often highly effective, transparent, and ethically desirable tools for improving decision making, changing attitudes, and reducing risky behavior. Theoretical mechanisms, open questions, and emerging applications are discussed.

Simple but powerful health messages for increasing condom use in young adults

In a large longitudinal study involving young adults, we conducted an eight-hour STD educational intervention and examined the impact of the intervention on the efficacy of a message for promoting condom use. The message was framed in positive or negative terms and was presented visually or in numbers (percentages or frequencies). Results indicated that the numerical positive-framed message increased condom use among young adults who did not receive the intervention, whereas the numerical negative-framed message did not. Attitudes toward condom use along with changes in intentions to use condoms mediated this framing effect. In contrast, the positive-framed and negative-framed messages were equally and highly effective for promoting condom use when the messages were presented visually or when young adults received the STD educational intervention before reading the message, suggesting that the simple brochures featuring visual aids were as effective in changing attitudes and behavioral intentions as the extensive intervention. These findings add to a growing body of evidence detailing the mechanisms that allow well-constructed visual aids to be among the most effective, transparent, memorable, and ethically desirable means of risk communication. Clinical and public health implications are discussed.

Informing the uninformed: optimizing the consent message using a fractional factorial design

IMPORTANCE

Research information should be presented in a manner that promotes understanding. However, many parents and research subjects have difficulty understanding and making informed decisions.

OBJECTIVE

To examine the effect of different communication strategies on parental understanding of research information.

DESIGN

Observational study from January 2010 to June 2012 using a fractional factorial design.

SETTING

Large tertiary care children's hospital.

PARTICIPANTS

Six hundred forty parents of children scheduled for elective surgery.

INTERVENTIONS

Parents were randomized to receive information about a hypothetical pain trial presented in 1 of 16 consent documents containing different combinations of 5 selected communication strategies (ie, length, readability, processability [formatting], graphical display, and supplemental verbal disclosure).

MAIN OUTCOME AND MEASURES

Parents were interviewed to determine their understanding of the study elements (eg, protocol and alternatives) and their gist (main point) and verbatim (actual) understanding of the risks and benefits.

RESULTS

Main effects for understanding were found for processability, readability, message length, use of graphics, and verbal discussion. Consent documents with high processability, eighth-grade reading level, and graphics resulted in significantly greater gist and verbatim understanding compared with forms without these attributes (mean difference, 0.57; 95% CI, 0.26-0.88, number of correct responses of 7 and mean difference, 0.54; 95% CI,0.20-0.88, number of correct responses of 4 for gist and verbatim, respectively).

CONCLUSIONS AND RELEVANCE

Results identified several communication strategy combinations that improved parents' understanding of research information. Adoption of these active strategies by investigators, clinicians, institutional review boards, and study sponsors represents a simple, practical, and inexpensive means to optimize the consent message and enhance parental, participant, and patient understanding.

Development and initial evaluation of a treatment decision dashboard

Background

For many healthcare decisions, multiple alternatives are available with different combinations of advantages and disadvantages across several important dimensions. The complexity of current healthcare decisions thus presents a significant barrier to informed decision making, a key element of patient-centered care.

Interactive decision dashboards were developed to facilitate decision making in Management, a field marked by similarly complicated choices. These dashboards utilize data visualization techniques to reduce the cognitive effort needed to evaluate decision alternatives and a non-linear flow of information that enables users to review information in a self-directed fashion. Theoretically, both of these features should facilitate informed decision making by increasing user engagement with and understanding of the decision at hand. We sought to determine if the interactive decision dashboard format can be successfully adapted to create a clinically realistic prototype patient decision aid suitable for further evaluation and refinement.

Methods

We created a computerized, interactive clinical decision dashboard and performed a pilot test of its clinical feasibility and acceptability using a multi-method analysis. The dashboard summarized information about the effectiveness, risks of side effects and drug-drug interactions, out-of-pocket costs, and ease of use of nine analgesic treatment options for knee osteoarthritis. Outcome evaluations included observations of how study participants utilized the dashboard, questionnaires to assess usability, acceptability, and decisional conflict, and an open-ended qualitative analysis.

Results

The study sample consisted of 25 volunteers - 7 men and 18 women - with an average age of 51 years. The mean time spent interacting with the dashboard was 4.6 minutes. Mean evaluation scores on scales ranging from 1 (low) to 7 (high) were: mechanical ease of use 6.1, cognitive ease of use 6.2, emotional difficulty 2.7, decision-aiding effectiveness 5.9, clarification of values 6.5, reduction in decisional uncertainty 6.1, and provision of decision-related information 6.0. Qualitative findings were similarly positive.

Conclusions

Interactive decision dashboards can be adapted for clinical use and have the potential to foster informed decision making. Additional research is warranted to more rigorously test the effectiveness and efficiency of patient decision dashboards for supporting informed decision making and other aspects of patient-centered care, including shared decision making.

Health providers' perceptions of novel approaches to visualizing integrated health information

OBJECTIVES

We evaluated the design of three novel visualization techniques for integrated health information with health care providers in older adult care. Through focus groups, we identified generalizable themes related to the visualization and interpretation of health information. Using these themes we address challenges with visualizing integrated health information and provide recommendations for designers.

METHODS

We recruited ten health care providers to participate in three focus groups. We applied a qualitative descriptive approach to code and extract themes related to the visualization of graphical displays.

RESULTS

We identified a set of four common themes across focus groups related to: 1) Trust in data for decision-making; 2) Perceived level of detail for visualization (subthemes: holistic, individual components); 3) Cognitive issues (subthemes: training and experience; cognitive overload; contrast); and 4) Application of visual displays. Furthermore, recommendations are provided as part of the iterative design process for the visualizations.

CONCLUSIONS

Data visualization of health information is an important component of care, impacting both the accuracy and speed of decision making. There are both functional and cognitive elements to consider during the development of appropriate visualizations that integrate different components of health.

Using animated computer-generated text and graphics to depict the risks and benefits of medical treatment

OBJECTIVE

Conventional print materials for presenting risks and benefits of treatment are often difficult to understand. This study was undertaken to evaluate and compare subjects' understanding and perceptions of risks and benefits presented using animated computerized text and graphics.

METHODS

Adult subjects were randomized to receive identical risk/benefit information regarding taking statins that was presented on an iPad (Apple Corp, Cupertino, Calif) in 1 of 4 different animated formats: text/numbers, pie chart, bar graph, and pictograph. Subjects completed a questionnaire regarding their preferences and perceptions of the message delivery together with their understanding of the information. Health literacy, numeracy, and need for cognition were measured using validated instruments.

RESULTS

There were no differences in subject understanding based on the different formats. However, significantly more subjects preferred graphs (82.5%) compared with text (17.5%, P<.001). Specifically, subjects preferred pictographs (32.0%) and bar graphs (31.0%) over pie charts (19.5%) and text (17.5%). Subjects whose preference for message delivery matched their randomly assigned format (preference match) had significantly greater understanding and satisfaction compared with those assigned to something other than their preference.

CONCLUSIONS

Results showed that computer-animated depictions of risks and benefits offer an effective means to describe medical risk/benefit statistics. That understanding and satisfaction were significantly better when the format matched the individual's preference for message delivery is important and reinforces the value of "tailoring" information to the individual's needs and preferences.