A Demonstration of "Less Can Be More" in Risk Graphics

VA Health Services Research & Development Center for Clinical Management Research, VA Ann Arbor Healthcare System, Ann Arbor, MI, USA.
Medical Decision Making (Impact Factor: 3.24). 04/2010; 30(6):661-71. DOI: 10.1177/0272989X10364244
Source: PubMed


Online tools such as Adjuvant! provide tailored estimates of the possible outcomes of adjuvant therapy options available to breast cancer patients. The graphical format typically displays 4 outcomes simultaneously: survival, mortality due to cancer, other-cause mortality, and incremental survival due to adjuvant treatment.
To test whether simpler formats that present only baseline and incremental survival would improve comprehension of the relevant risk statistics and/or affect treatment intentions.
. Randomized experimental manipulation of risk graphics shown included in Internet-administered survey vignettes about adjuvant therapy decisions for breast cancer patients with ER + tumors.
Demographically diverse, stratified random samples of women ages 40 to 74 y recruited from an Internet research panel.
Participants were randomized to view either pictographs (icon arrays) that displayed all 4 possible outcomes or pictographs that showed only survival outcomes.
Comprehension of key statistics, task completion times, graph evaluation ratings, and perceived interest in adjuvant chemotherapy.
In the primary study (N = 832), participants who viewed survival-only pictographs had better accuracy when reporting the total chance of survival with both chemotherapy and hormonal therapy (63% v. 50%, P < 0.001), higher graph evaluation ratings (x = 7.98 v. 7.67, P = 0.04), and less interest in adding chemotherapy to hormonal therapy (43% v. 50%, P = 0.04; adjusted odds ratio [OR] = 0.68, P = 0.008). A replication study (N = 714) confirmed that participants who viewed survival-only graphs had higher graph evaluation ratings (x = 8.06 v. 7.72, P = 0.04) and reduced interest in chemotherapy (OR=0.67,P=0.03).
Studies used general public samples; actual patients may process risk information differently.
Taking a ''less is more'' approach by omitting redundant mortality outcome statistics can be an effective method of risk communication and may be preferable when using visual formats such as pictographs.

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    • "Another study showed that different visual formats supported gist versus verbatim knowledge [68]. Enhancing accuracy in estimates can be aided by displaying only the most crucial elements [71,72], as well as by using icon arrays (blocks or stick figures) that are arranged as groups in a block rather than being scattered randomly -- the latter of which is useful to convey the concept that events (e.g., who is afflicted by disease) occur at random [73]. "
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    ABSTRACT: Making evidence-based decisions often requires comparison of two or more options. Research-based evidence may exist which quantifies how likely the outcomes are for each option. Understanding these numeric estimates improves patients' risk perception and leads to better informed decision making. This paper summarises current "best practices" in communication of evidence-based numeric outcomes for developers of patient decision aids (PtDAs) and other health communication tools. An expert consensus group of fourteen researchers from North America, Europe, and Australasia identified eleven main issues in risk communication. Two experts for each issue wrote a "state of the art" summary of best evidence, drawing on the PtDA, health, psychological, and broader scientific literature. In addition, commonly used terms were defined and a set of guiding principles and key messages derived from the results. The eleven key components of risk communication were: 1) Presenting the chance an event will occur; 2) Presenting changes in numeric outcomes; 3) Outcome estimates for test and screening decisions; 4) Numeric estimates in context and with evaluative labels; 5) Conveying uncertainty; 6) Visual formats; 7) Tailoring estimates; 8) Formats for understanding outcomes over time; 9) Narrative methods for conveying the chance of an event; 10) Important skills for understanding numerical estimates; and 11) Interactive web-based formats. Guiding principles from the evidence summaries advise that risk communication formats should reflect the task required of the user, should always define a relevant reference class (i.e., denominator) over time, should aim to use a consistent format throughout documents, should avoid "1 in x" formats and variable denominators, consider the magnitude of numbers used and the possibility of format bias, and should take into account the numeracy and graph literacy of the audience. A substantial and rapidly expanding evidence base exists for risk communication. Developers of tools to facilitate evidence-based decision making should apply these principles to improve the quality of risk communication in practice.
    BMC Medical Informatics and Decision Making 11/2013; 13 Suppl 2(Suppl 2):S7. DOI:10.1186/1472-6947-13-S2-S7 · 1.83 Impact Factor
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    • "Investigators of TTO tend to have a preference for the use of graphs/illustrations to present the choice situation, since it appears that respondents find this easier than a numerical description [45, 46]. In the old days, TTO boards were commonly used. "
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    ABSTRACT: There is no scientific consensus on the optimal specification of the time trade-off (TTO) task. As a consequence, studies using TTO to value health states may share the core element of trading length of life for quality of life, but can differ considerably on many other elements. While this pluriformity in specifications advances the understanding of TTO from a methodological point of view, it also results in incomparable health state values. Health state values are applied in health technology assessments, and in that context comparability of information is desired. In this article, we discuss several alternative specifications of TTO presented in the literature. The defining elements of these specifications are identified as being either methodological, procedural or analytical in nature. Where possible, it is indicated how these elements affect health state values (i.e., upward or downward). Finally, a checklist for TTO studies is presented, which incorporates a list of choices to be made by researchers who wish to perform a TTO task. Such a checklist enables other researchers to align methodologies in order to enhance the comparability of health state values.
    The European Journal of Health Economics 07/2013; 14(1). DOI:10.1007/s10198-013-0508-x · 2.10 Impact Factor
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    • "The effectiveness of specific graphics rely on numerous aspects, including display characteristic (e.g., layout, use of cues and colours), data complexity, user characteristics (e.g., cognitive styles and demands) and the task at hand and cognitive load on individuals [34] [40]. The amount of information within a visual has been researched in [48], looking towards reducing complexity with a 'less is more' approach—of course the potential issue here is not displaying both frames of information and thus risking biasing judgement. Nonetheless, this paper does give a good example of the ongoing work in this area. "
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    ABSTRACT: Slowly but surely, academia and industry are fully accepting the importance of the human element as it pertains to achieving security and trust. Undoubtedly, one of the main motivations for this is the increase in attacks (e.g., social engi-neering and phishing) which exploit humans and exemplify why many authors regard them as the weakest link in the security chain. As research in the socio-technical security and trust fields gains momentum, it is crucial to intermittently pause and reflect on their progress while also considering related domains to determine whether there are any established principles which may be transferred. Comparison of the states-of-the-arts may assist in planning work going forward and identifying useful future directions for the less mature socio-technical field. This paper seeks to fulfil several of these goals, particularly as they relate to the emerging cybersecurity-risk communication domain. The literature reviews which we conduct here are beneficial and indeed noteworthy as they pull together a number of the key aspects which may affect the trustworthiness and effectiveness of communications on cybersecurity risks. In particular, we draw on information-trustworthiness research and the established field of risk communication. An appreciation of these aspects and precepts is imperative if systems are to be designed that play to individuals' strengths and assist them in maintaining security and protecting their applications and information.
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