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BackgroundThe increasing use of computer-administered risk communications affords the potential to replace static risk graphics with animations that use motion cues to reinforce key risk messages. Research on the use of animated graphics, however, has yielded mixed findings, and little research exists to identify the specific animations that might improve risk knowledge and patients’ decision making. ObjectiveTo test whether viewing animated forms of standard pictograph (icon array) risk graphics displaying risks of side effects would improve people’s ability to select the treatment with the lowest risk profile, as compared with viewing static images of the same risks. MethodsA total of 4198 members of a demographically diverse Internet panel read a scenario about two hypothetical treatments for thyroid cancer. Each treatment was described as equally effective but varied in side effects (with one option slightly better than the other). Participants were randomly assigned to receive all risk information in 1 of 10 pictograph formats in a quasi-factorial design. We compared a control condition of static grouped icons with a static scattered icon display and with 8 Flash-based animated versions that incorporated different combinations of (1) building the risk 1 icon at a time, (2) having scattered risk icons settle into a group, or (3) having scattered risk icons shuffle themselves (either automatically or by user control). We assessed participants’ ability to choose the better treatment (choice accuracy), their gist knowledge of side effects (knowledge accuracy), and their graph evaluation ratings, controlling for subjective numeracy and need for cognition. ResultsWhen compared against static grouped-icon arrays, no animations significantly improved any outcomes, and most showed significant performance degradations. However, participants who received animations of grouped icons in which at-risk icons appeared 1 at a time performed as well on all outcomes as the static grouped-icon control group. Displays with scattered icons (static or animated) performed particularly poorly unless they included the settle animation that allowed users to view event icons grouped. ConclusionsMany combinations of animation, especially those with scattered icons that shuffle randomly, appear to inhibit knowledge accuracy in this context. Static pictographs that group risk icons, however, perform very well on measures of knowledge and choice accuracy. These findings parallel recent evidence in other data communication contexts that less can be more—that is, that simpler, more focused information presentation can result in improved understanding. Decision aid designers and health educators should proceed with caution when considering the use of animated risk graphics to compare two risks, given that evidence-based, static risk graphics appear optimal.

Background. In a companion article, the authors describe the Subjective Numeracy Scale (SNS), a self-assessment of numerical aptitude and preferences for numbers that correlates strongly with objective numeracy. Objective. The objective of this article is to validate the Subjective Numeracy Scale using measures of subjects' capacity to recall and comprehend complex risk statistics and to complete utility elicitations. Research Design. The study is composed of 3 general public surveys: 2 administered via the Web and 1 by paper and pencil. Subjects. Studies 1 and 3 surveyed 862 and 1234 people, respectively, recruited via a nationwide commercial Internet survey panel. Study 2 involved 245 people who completed paper-and-pencil surveys in a Veterans Administration hospital. Measures. The authors tested whether one's score on the SNS predicted the likelihood of correct recall and interpretation of risk information (studies 1 and 2A) or the likelihood of effectively completing a time tradeoff or person-tradeoff utility elicitation (studies 2B and 3). In Studies 1 and 2, the authors also tested whether an objective test of quantitative ability would predict performance. Results. In all studies, survey participants with higher SNS scores performed significantly better than other respondents. The predictive ability of the SNS approached that observed for objective numeracy. Conclusions. The SNS effectively predicts both risk comprehension and completion of utility elicitations without requiring survey participants to complete time-consuming and stress-inducing mathematics tests. The authors encourage the use of the SNS in a variety of health services research contexts. Key words: numeracy; risk communication; decision making; literacy; utility measurement. (Med Decis Making 2007;27:663-671), The Subjective Numeracy Scale (SNS) is a self-report measure of perceived ability to perform various mathematical tasks and preference for the use of numerical versus prose information.(1) The 8-item scale [...]

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. Paper-and-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, To make informed decisions, patients need to be aware of and understand the risks and benefits of their treatment options. However, many patients have substantial difficulty understanding such risks and [...]

Objective. Person tradeoff (PTO) elicitations assess people's values for health states by asking them to compare the value of treatment programs. For example, people might be asked how many patients [...]

BackgroundOnline risk calculators offer different levels of precision in their risk estimates. People interpret numbers in varying ways depending on how they are presented, and we do not know how the number of decimal places displayed might influence perceptions of risk estimates. ObjectiveThe objective of our study was to determine whether precision (ie, number of decimals) in risk estimates offered by an online risk calculator influences users’ ratings of (1) how believable the estimate is, (2) risk magnitude (ie, how large or small the risk feels to them), and (3) how well they can recall the risk estimate after a brief delay. MethodsWe developed two mock risk calculator websites that offered hypothetical percentage estimates of participants’ lifetime risk of kidney cancer. Participants were randomly assigned to a condition where the risk estimate value rose with increasing precision (2, 2.1, 2.13, 2.133) or the risk estimate value fell with increasing precision (2, 1.9, 1.87, 1.867). Within each group, participants were randomly assigned one of the four numbers as their first risk estimate, and later received one of the remaining three as a comparison. ResultsParticipants who completed the experiment (N = 3422) were a demographically diverse online sample, approximately representative of the US adult population on age, gender, and race. Participants whose risk estimates had no decimal places gave the highest ratings of believability (F3,3384 = 2.94, P = .03) and the lowest ratings of risk magnitude (F3,3384 = 4.70, P = .003). Compared to estimates with decimal places, integer estimates were judged as highly believable by 7%–10% more participants (χ23 =17.8, P < .001). When comparing two risk estimates with different levels of precision, large majorities of participants reported that the numbers seemed equivalent across all measures. Both exact and approximate recall were highest for estimates with zero decimals. Odds ratios (OR) for correct approximate recall (defined as being within 50% of the original estimate) were, for one decimal place, OR = 0.65 (95% CI 0.49–0.86), for two decimal places, OR = 0.70 (95% CI 0.53–0.94), and for three decimal places, 0.61 (95% CI 0.45–0.81). Exact recall showed a similar pattern, with larger effects. ConclusionsThere are subtle but measurable differences in how people interpret risk estimates of varying precision. Adding decimal places in risk calculators offers little to no benefit and some cost. Rounding to the nearest integer is likely preferable for communicating risk estimates via risk calculators so that they might be remembered correctly and judged as believable.

Background Paper-based patient decision aids generally present risk information using numbers and/or static images. However, limited psychological research has suggested that when people interactively graph risk information, they process the statistics more actively, making the information more available for decision making. Such interactive tools could potentially be incorporated in a new generation of Web-based decision aids. Objective The objective of our study was to investigate whether interactive graphics detailing the risk of side effects of two treatments improve knowledge and decision making over standard risk graphics. Methods A total of 3371 members of a demographically diverse Internet panel viewed a hypothetical scenario about two hypothetical treatments for thyroid cancer. Each treatment had a chance of causing 1 of 2 side effects, but we randomly varied whether one treatment was better on both dimensions (strong dominance condition), slightly better on only one dimension (mild dominance condition), or better on one dimension but worse on the other (trade-off condition) than the other treatment. We also varied whether respondents passively viewed the risk information in static pictograph (icon array) images or actively manipulated the information by using interactive Flash-based animations of “fill-in-the-blank” pictographs. Our primary hypothesis was that active manipulation would increase respondents’ ability to recognize dominance (when available) and choose the better treatment. Results The interactive risk graphic conditions had significantly worse survey completion rates (1110/1695, 65.5% vs 1316/1659, 79.3%, P < .001) than the static image conditions. In addition, respondents using interactive graphs were less likely to recognize and select the dominant treatment option (234/380, 61.6% vs 343/465, 73.8%, P < .001 in the strong dominance condition). Conclusions Interactivity, however visually appealing, can both add to respondent burden and distract people from understanding relevant statistical information. Decision-aid developers need to be aware that interactive risk presentations may create worse outcomes than presentations of static risk graphic formats.

Background Approximately half of American adults do not meet recommended physical activity guidelines. Face-to-face lifestyle interventions improve health outcomes but are unlikely to yield population-level improvements because they can be difficult to disseminate, expensive to maintain, and inconvenient for the recipient. In contrast, Internet-based behavior change interventions can be disseminated widely at a lower cost. However, the impact of some Internet-mediated programs is limited by high attrition rates. Online communities that allow participants to communicate with each other by posting and reading messages may decrease participant attrition. Objective Our objective was to measure the impact of adding online community features to an Internet-mediated walking program on participant attrition and average daily step counts. Methods This randomized controlled trial included sedentary, ambulatory adults who used email regularly and had at least 1 of the following: overweight (body mass index [BMI] ≥ 25), type 2 diabetes, or coronary artery disease. All participants (n = 324) wore enhanced pedometers throughout the 16-week intervention and uploaded step-count data to the study server. Participants could log in to the study website to view graphs of their walking progress, individually-tailored motivational messages, and weekly calculated goals. Participants were randomized to 1 of 2 versions of a Web-based walking program. Those randomized to the “online community” arm could post and read messages with other participants while those randomized to the “no online community" arm could not read or post messages. The main outcome measures were participant attrition and average daily step counts over 16 weeks. Multiple regression analyses assessed the effect of the online community access controlling for age, sex, disease status, BMI, and baseline step counts. Results Both arms significantly increased their average daily steps between baseline and the end of the intervention period, but there were no significant differences in increase in step counts between arms using either intention-to-treat or completers analysis. In the intention-to-treat analysis, the average step count increase across both arms was 1888 ± 2400 steps. The percentage of completers was 13% higher in the online community arm than the no online community arm (online community arm, 79%, no online community arm, 66%, P = .02). In addition, online community arm participants remained engaged in the program longer than no online community arm participants (hazard ratio = 0.47, 95% CI = 0.25 - 0.90, P = .02). Participants with lower baseline social support posted more messages to the online community (P < .001) and viewed more posts (P < .001) than participants with higher baseline social support. Conclusion Adding online community features to an Internet-mediated walking program did not increase average daily step counts but did reduce participant attrition. Participants with low baseline social support used the online community features more than those with high baseline social support. Thus, online communities may be a promising approach to reducing attrition from online health behavior change interventions, particularly in populations with low social support. Trial RegistrationNCT00729040; http://clinicaltrials.gov/ct2/show/NCT00729040 (Archived by WebCite at http://www.webcitation.org/5v1VH3n0A)

Purpose. When making medical decisions, people often care not only about what happens but also about whether the outcome was a result of actions voluntarily taken or a result of [...]

Patients with chronic health conditions often rate their quality of life (QoL) significantly higher than non-patients. One explanation for this discrepancy is that non-patients focus on the negative aspects of the onset of a condition, especially the early difficulties people face when they first experience a debilitating condition, without considering that patients can adapt to it over time. To test this hypothesis, we had 359 people perform person tradeoff (PTO) elicitations in an online survey, varying whether the treatment programs under consideration saved the lives of patients (a) with pre-existing paraplegia; or (b) who would experience new onset of paraplegia. Half of each group completed an 'adaptation exercise' which encouraged them to consider their own ability to emotionally adapt to negative events in general and specifically to having paraplegia. The adaptation manipulation increased the value participants placed on pre-existing paraplegia (p = 0.03) and on new onset paraplegia (p = 0.05), relative to saving healthy lives. Moreover, the adaptation exercise dramatically reduced the differences between evaluations of pre-existing and new onset paraplegia to values within 2% of each other. Our findings suggest that asking non-patients to do an adaptation exercise before giving QoL ratings may help close the gap in ratings between patients and citizen non-patients. Keywords: Adaptation; Person tradeoff; Health state valuation; Cost-effectiveness analysis; Utility measure; Internet survey

The phenomenon of ambiguity aversion suggests that people prefer options that offer precisely rather than imprecisely known chances of success. However, past work on people's responses to ambiguity in health treatment contexts found ambiguity seeking rather than aversion. The present work addressed whether such findings reflected a broad tendency for ambiguity seeking in health treatment contexts or whether specific attributions for ambiguity play a substantial role. In three studies, people choose between two treatment options that involved similar underlying probabilities, except that the probabilities for one option involved ambiguity. The attributions offered for the ambiguity played an important role in the results. For example, when the range of probabilities associated with an ambiguous treatment was attributed to the fact that different studies yield different results, participants tended to show ambiguity aversion or indifference. However, when the range was attributed to something that participants could control (e.g., regular application of a cream) or something about which they were overoptimistic (e.g., their immune system function), participants tended to show ambiguity seeking. Health professionals should be mindful of how people will interpret and use information about ambiguity when choosing among treatments. [ABSTRACT FROM AUTHOR]

Background: To the authors' knowledge, studies regarding risk perception among survivors of thyroid cancer are scarce.Methods: The authors surveyed patients who were diagnosed with differentiated thyroid cancer from the Surveillance, Epidemiology, and End Results registries of Georgia and Los Angeles County (2632 patients; 63% response rate). The analytic cohort was defined by a ≤5% risk of disease recurrence and mortality (1597 patients). Patients estimated their recurrence and mortality risks separately (increments of 10% and endpoints of ≤5% and ≥95%). Both outcomes were dichotomized between reasonably accurate estimates (risk perception of ≤5% or 10%) versus overestimation (risk perception of ≥20%). Multivariable logistic regression was used to identify factors associated with risk overestimation, and the relationships between overestimation and both worry and quality of life were evaluated.Results: In the current study sample, 24.7% of patients overestimated their recurrence risk and 12.5% overestimated their mortality risk. A lower educational level was associated with overestimating disease recurrence (≤high school diploma: odds ratio [OR], 1.64 [95% CI, 1.16-2.31]; and some college: OR, 1.36 [95% CI, 1.02-1.81]) and mortality (≤high school diploma: OR, 1.86 [95% CI, 1.18-2.93]) risk compared with those attaining at least a college degree. Hispanic ethnicity was found to be associated with overestimating recurrence risk (OR, 1.44, 95% CI 1.02-2.03) compared with their white counterparts. Worry about recurrence and death was found to be greater among patients who overestimated versus those who had a reasonably accurate estimate of their risk of disease recurrence and mortality, respectively (P < .001). Patients who overestimated mortality risk also reported a decreased physical quality of life (mean T score, 43.1; 95% CI, 41.6-44.7) compared with the general population.Conclusions: Less educated patients and Hispanic patients were more likely to report inaccurate risk perceptions, which were associated with worry and a decreased quality of life. [ABSTRACT FROM AUTHOR]

Influenza strains are referred to in several ways by infectious disease experts, public health officials, clinicians, and the media when communicating with the public. These influenza strain labels can focus [...]