Comparing the impact of an icon array versus a bar graph on preference and understanding of risk information: Results from an online, randomized study.
TL;DR: In this paper, the authors 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.
Abstract: 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.
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TL;DR: In this article , the authors discuss the iterative process that is used to improve the design of a decision aid (DA) developed to facilitate shared decision-making, and explain the use of eye tracking during this process to examine how users processed the information provided by the DA.
Abstract: Eye tracking has become the gold standard in measuring human attention and information-processing behavior. As such, eye tracking in mixed-methods user experience (UX) research serves as an invaluable tool to learn about user needs and to create actionable insights for improving product and service design during the development cycle. Here, we discuss the iterative process that we used to improve the design of a decision aid (DA) developed to facilitate shared decision making. We explain the use of eye tracking during this process to examine how users processed the information provided by the DA. We also explain how we used eye tracking in a retrospective “think-aloud” protocol to gain insight about users’ needs. Our results show that user reactions captured by eye tracking can not only be used to optimize design decisions but also to gather user feedback about their information processing needs.
19 Jan 2023
TL;DR: In this article , the authors evaluated the effect of risk communication tools on the understanding of statistical risk of complications occurring in patients undergoing a surgical or interventional procedure and found that the most common risk communication tool used was additional written information (n=7).
Abstract: ABSTRACT Objective Evaluate the effect of risk communication tools on the understanding of statistical risk of complications occurring in patients undergoing a surgical or interventional procedure. Summary Background Data Informed consent is an essential process in clinical decision-making, through which healthcare providers educate patients about the benefits, risks and alternatives of a procedure. Numerical risk information is by nature probabilistic and difficult to communicate. Aids which support statistical risk communication and studies assessing their effectiveness are needed. Methods A systematic search was performed across Medline, Embase, PsycINFO, Scopus and Web of Science until July 2021 with a repeated search in September 2022. Studies examining risk communication tools (e.g. informative leaflets, audio-video) in adults (age>16) patients undergoing a surgical or interventional procedure were included. Studies only assessing understanding of non-statistical aspects of the procedure were excluded. Both randomised control trials (RCTs) and observational studies were included. Cochrane risk-of-bias and the Newcastle-Ottawa Scale were used to assess the quality of studies. Due to heterogeneity of the studies, a narrative synthesis was performed (PROSPERO ID: CRD42022285789). Results A total of 4348 articles were identified and following abstract and full-text screening a total of 11 articles were included. 8 studies were RCTs and 3 were cross-sectional. The total number of adult patients was 1030. The most common risk communication tool used was additional written information (n=7). Of the 8 RCTs, 5 showed statistically significant improvements in the intervention group in outcomes relating to recall of statistical risk. Quality assessment of RCTs found some concerns with all studies. Conclusions Risk communication tools appear to improve recall of statistical risk. Additional prospective trials are warranted which can compare various aids and determine the most effective method of improving patient understanding.
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TL;DR: A single question may be useful for detecting patients with inadequate health literacy in a VA population and AUROCs were lower for detecting “inadequate or marginal” health literacy than for detecting inadequate health Literacy for each of the 3 questions.
Abstract: Previous studies have shown that a single question may identify individuals with inadequate health literacy. We evaluated and compared the performance of 3 health literacy screening questions for detecting patients with inadequate or marginal health literacy in a large VA population. We conducted in-person interviews among a random sample of patients from 4 VA medical centers that included 3 health literacy screening questions and 2 validated health literacy measures. Patients were classified as having inadequate, marginal, or adequate health literacy based on the Short Test of Functional Health Literacy in Adults (S-TOFHLA) and the Rapid Estimate of Adult Literacy in Medicine (REALM). We evaluated the ability of each of 3 questions to detect: 1) inadequate and the combination of “inadequate or marginal” health literacy based on the S-TOFHLA and 2) inadequate and the combination of “inadequate or marginal” health literacy based on the REALM. Of 4,384 patients, 1,796 (41%) completed interviews. The prevalences of inadequate health literacy were 6.8% and 4.2%, based on the S-TOHFLA and REALM, respectively. Comparable prevalences for marginal health literacy were 7.4% and 17%, respectively. For detecting inadequate health literacy, “How confident are you filling out medical forms by yourself?” had the largest area under the Receiver Operating Characteristic Curve (AUROC) of 0.74 (95% CI: 0.69–0.79) and 0.84 (95% CI: 0.79–0.89) based on the S-TOFHLA and REALM, respectively. AUROCs were lower for detecting “inadequate or marginal” health literacy than for detecting inadequate health literacy for each of the 3 questions. A single question may be useful for detecting patients with inadequate health literacy in a VA population.
1,116 citations
TL;DR: The goal was to understand how numeracy affects women's ability to gauge the benefit of mammography after receiving quantitative information, and to hypothesized that the ability to use quantitative risk information would be related to the level of numeracy.
Abstract: Background: Quantitative information about risks and benefits may be meaningful only to patients who have some facility with basic probability and numerical concepts, a construct called numeracy. O...
1,043 citations
TL;DR: The Subjective Numeracy Scale (SNS), an 8-item measure, correlates well with mathematical test measures of objective numeracy but can be administered in less time and with less burden, and shows much lower rates of missing or incomplete data.
Abstract: Background. Basic numeracy skills are necessary before patients can understand the risks of medical treatments. Previous research has used objective measures, similar to mathematics tests, to evaluate numeracy. Objectives. To design a subjective measure (i.e., self-assessment) of quantitative ability that distinguishes low- and high-numerate individuals yet is less aversive, quicker to administer, and more useable for telephone and Internet surveys than existing numeracy measures. Research Design. Paperand-pencil questionnaires. Subjects. The general public (N =703) surveyed at 2 hospitals. Measures. Forty-nine subjective numeracy questions were compared to measures of objective numeracy. Results. An 8-item measure, the Subjective Numeracy Scale (SNS), was developed through several rounds of testing. Four items measure people’s beliefs about their skill in performing various mathematical operations, and 4 measure people’s preferences regarding the presentation of numerical information. The SNS was significantly correlated with Lipkus and others’ objective numeracy scale (correlations: 0.63‐0.68) yet was completed in less time (24 s/item v. 31 s/item, P <0:05) and was perceived as less stressful (1.62 v. 2.69, P <0:01) and less frustrating (1.92 v. 2.88, P <0:01). Fifty percent of participants who completed the SNS volunteered to participate in another study, whereas only 8% of those who completed the Lipkus and others scale similarly volunteered (odds ratio =11.00, 95% confidence interval =2.14‐56.65). Conclusions. The SNS correlates well with mathematical test measures of objective numeracy but can be administered in less time and with less burden. In addition, it is much more likely to leave participants willing to participate in additional research and shows much lower rates of missing or incomplete data.
777 citations
TL;DR: A glance at the literature shows a shocking lack of statistical understanding of the outcomes of modern technologies, from standard screening tests for HIV infection to DNA evidence.
Abstract: Bad presentation of medical statistics such as the risks associated with a particular intervention can lead to patients making poor decisions on treatment. Particularly confusing are single event probabilities, conditional probabilities (such as sensitivity and specificity), and relative risks. How can doctors improve the presentation of statistical information so that patients can make well informed decisions?
712 citations
TL;DR: Best practices for conveying magnitude of health risks using numeric, verbal, and visual formats are offered and several recommendations are suggested for enhancing precision in perception of risk by presenting risk magnitudes numerically and visually.
Abstract: 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 (ie, 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 (eg, 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
685 citations