Validation of the Subjective Numeracy Scale: effects of low numeracy on comprehension of risk communications and utility elicitations

Health literacy, numeracy, and other characteristics associated with hospitalized patients' preferences for involvement in decision making

Little research has examined the association of health literacy and numeracy with patients' preferred involvement in the problem-solving and decision-making process in the hospital. Using a sample of 1,249 patients hospitalized with cardiovascular disease from the Vanderbilt Inpatient Cohort Study (VICS), we assessed patients' preferred level of involvement using responses to two scenarios of differing symptom severity from the Problem-Solving Decision-Making Scale. Using multivariable modeling, we determined the relationship of health literacy, subjective numeracy, and other patient characteristics with preferences for involvement in decisions, and how this differed by scenario. The authors found that patients with higher levels of health literacy desired more participation in the problem-solving and decision-making process, as did patients with higher subjective numeracy skills, greater educational attainment, female gender, less perceived social support, or greater health care system distrust (p<.05 for each predictor in multivariable models). Patients also preferred to participate more in the decision-making process when the hypothetical symptom they were experiencing was less severe (i.e., they deferred more to their physician when the hypothetical symptom was more severe). These findings underscore the role that patient characteristics, especially health literacy and numeracy, play in decisional preferences among hospitalized patients.

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

BACKGROUND

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

METHOD

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

RESULTS

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

CONCLUSION

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

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.

Format-dependent representations of symbolic and non-symbolic numbers in the human cortex as revealed by multi-voxel pattern analyses

Neuroimaging studies in the last 20 years have tried to unravel the neural correlates of number processing across formats in humans and non-human primates. Results point to the intraparietal sulcus as the core area for an abstract representation of numerical quantity. On the other hand, there exist a variety of behavioral and neuroimaging data that are difficult to reconcile with the existence of such an abstract representation. In this study, we addressed this issue by applying multi-voxel pattern analysis (MVPA) to functional Magnetic Resonance Imaging (fMRI) data to unravel the neural representations of symbolic (digits) and non-symbolic (dots) numbers and their possible overlap on three different spatial scales (entire lobules, smaller regions of interest and a searchlight analysis with 2-voxel radius). Results showed that numbers in both formats are decodable in occipital, frontal, temporal and parietal regions. However, there were no overlapping representations between dots and digits on any of the spatial scales. These data suggest that the human brain does not contain an abstract representation of numerical magnitude.

Shared decision-making to improve attention-deficit hyperactivity disorder care

OBJECTIVE

To examine the effect of a shared decision-making intervention with parents of children newly diagnosed with attention-deficit/hyperactivity disorder.

METHODS

Seven pediatricians participated in a pre/post open trial of decision aids for use before and during the office visit to discuss diagnosis and develop a treatment plan. Encounters pre- (n=21, control group) and post-intervention implementation (n=33, intervention group) were compared. We video-recorded encounters and surveyed parents.

RESULTS

Compared to controls, intervention group parents were more involved in shared decision-making (31.2 vs. 43.8 on OPTION score, p<0.01), more knowledgeable (6.4 vs. 8.1 questions correct, p<0.01), and less conflicted about treatment options (16.2 vs. 10.7 on decisional conflict total score, p=0.06). Visit duration was unchanged (41.0 vs. 41.6min, p=0.75). There were no significant differences in the median number of follow-up visits (0 vs. 1 visits, p=0.08), or the proportion of children with medication titration (62% vs. 76%, p=0.28), or parent-completed behavior rating scale to assess treatment response (24% vs. 39%, p=0.36).

CONCLUSIONS

Our intervention increased shared decision-making with parents. Parents were better informed about treatment options without increasing visit duration.

PRACTICE IMPLICATIONS

Interventions are available to prepare parents for visits and enable physicians to elicit parent preferences and involvement in decision-making.

How do physicians provide statistical information about antidepressants to hypothetical patients?

BACKGROUND

Little is known about how physicians provide statistical information to patients, which is important for informed consent.

METHODS

In a survey, obstetricians and gynecologists (N = 142) received statistical information about the benefit and side effects of an antidepressant. They received information in various formats, including event rates (antidepressant v. placebo), absolute risks, and relative risks. Participants had to imagine 2 hypothetical patients, 1 for whom they believed the drug to be safe and effective and 1 for whom they did not, and select the information they would give those patients. We assessed whether the information they selected for each patient was complete, transparent, interpretable, or persuasive (i.e., to nudge patients toward a particular option) and compared physicians who gave both patients the same information with those who gave both patients different information.

RESULTS

A similar proportion of physicians (roughly 25% each) selected information that was 1) complete and transparent, 2) complete but not transparent, 3) not interpretable for the patient because necessary comparative information was missing, or 4) suited for nudging. Physicians who gave both patients the same information (61% of physicians) more often selected at least complete information, even if it was often not transparent. Physicians who gave both patients different information (39% of physicians), in contrast, more often selected information that was suited for nudging in line with the belief they were asked to imagine. A limitation is that scenarios were hypothetical.

CONCLUSIONS

Most physicians did not provide complete and transparent information. Clinicians who presented consistent information to different patients tended to present complete information, whereas those who varied what information they chose to present appeared more prone to nudging.

Belief in numbers: When and why women disbelieve tailored breast cancer risk statistics

OBJECTIVE

To examine when and why women disbelieve tailored information about their risk of developing breast cancer.

METHODS

690 women participated in an online program to learn about medications that can reduce the risk of breast cancer. The program presented tailored information about each woman's personal breast cancer risk. Half of women were told how their risk numbers were calculated, whereas the rest were not. Later, they were asked whether they believed that the program was personalized, and whether they believed their risk numbers. If a woman did not believe her risk numbers, she was asked to explain why.

RESULTS

Beliefs that the program was personalized were enhanced by explaining the risk calculation methods in more detail. Nonetheless, nearly 20% of women did not believe their personalized risk numbers. The most common reason for rejecting the risk estimate was a belief that it did not fully account for personal and family history.

CONCLUSIONS

The benefits of tailored risk statistics may be attenuated by a tendency for people to be skeptical that these risk estimates apply to them personally.

PRACTICE IMPLICATIONS

Decision aids may provide risk information that is not accepted by patients, but addressing the patients' personal circumstances may lead to greater acceptance.

Cost concerns of patients with cancer

PURPOSE

Health care providers are accustomed to identifying populations for whom cost-related concerns may be a significant barrier, such as the poor, but few empiric data have been collected to substantiate such assumptions, particularly among insured patients.

METHODS

Patients with cancer from academic and community hospitals completed a questionnaire that included closed-ended items concerning demographic variables, optimism, numeracy, and concerns about present and future medical costs. In addition, they answered open-ended questions regarding cost concerns and medical expenses.

RESULTS

Nearly all (99%) participants were insured. In response to the closed-ended questions, 30.3% of patients reported concern about paying for their cancer treatment, 22.3% reported that their family had made sacrifices to pay for their care, and 8.3% stated that their insurance adequately covered their current health care costs, and 17.3% reported concerns about coverage for their costs in the future. On open-ended questions, 35.3% reported additional expenses, and 47.5% reported concerns about health care costs. None of the assessed patient characteristics proved to be a robust predictor across all cost-related concerns. There was a strong association between the identification of concerns or expenses on the open-ended questions and concerns on closed-ended questions.

CONCLUSION

Cost concerns are common among patients with cancer who have health insurance. Health care providers may alleviate concerns by discussing cost-related concerns with all patients, not only those of lower socioeconomic status or those without insurance. A closed-ended screening question may help to initiate these conversations. This may identify potential resources, lower distress, and enable patients to make optimal treatment decisions.

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 validation of the General Health Numeracy Test (GHNT)

OBJECTIVE

Because existing numeracy measures may not optimally assess 'health numeracy', we developed and validated the General Health Numeracy Test (GHNT).

METHODS

An iterative pilot testing process produced 21 GHNT items that were administered to 205 patients along with validated measures of health literacy, objective numeracy, subjective numeracy, and medication understanding and medication adherence. We assessed the GHNT's internal consistency reliability, construct validity, and explored its predictive validity.

RESULTS

On average, participants were 55.0 ± 13.8 years old, 64.9% female, 29.8% non-White, and 51.7% had incomes ≤$39K with 14.4 ± 2.9 years of education. Psychometric testing produced a 6-item version (GHNT-6). The GHNT-21 and GHNT-6 had acceptable-good internal consistency reliability (KR-20=0.87 vs. 0.77, respectively). Both versions were positively associated with income, education, health literacy, objective numeracy, and subjective numeracy (all p<.001). Furthermore, both versions were associated with participants' understanding of their medications and medication adherence in unadjusted analyses, but only the GHNT-21 was associated with medication understanding in adjusted analyses.

CONCLUSIONS

The GHNT-21 and GHNT-6 are reliable and valid tools for assessing health numeracy.

PRACTICE IMPLICATIONS

Brief, reliable, and valid assessments of health numeracy can assess a patient's numeracy status, and may ultimately help providers and educators tailor education to patients.

The influence of uncertain map features on risk beliefs and perceived ambiguity for maps of modeled cancer risk from air pollution

Maps are often used to convey information generated by models, for example, modeled cancer risk from air pollution. The concrete nature of images, such as maps, may convey more certainty than warranted for modeled information. Three map features were selected to communicate the uncertainty of modeled cancer risk: (i) map contours appeared in or out of focus, (ii) one or three colors were used, and (iii) a verbal-relative or numeric risk expression was used in the legend. Study aims were to assess how these features influenced risk beliefs and the ambiguity of risk beliefs at four assigned map locations that varied by risk level. We applied an integrated conceptual framework to conduct this full factorial experiment with 32 maps that varied by the three dichotomous features and four risk levels; 826 university students participated. Data was analyzed using structural equation modeling. Unfocused contours and the verbal-relative risk expression generated more ambiguity than their counterparts. Focused contours generated stronger risk beliefs for higher risk levels and weaker beliefs for lower risk levels. Number of colors had minimal influence. The magnitude of risk level, conveyed using incrementally darker shading, had a substantial dose-response influence on the strength of risk beliefs. Personal characteristics of prior beliefs and numeracy also had substantial influences. Bottom-up and top-down information processing suggest why iconic visual features of incremental shading and contour focus had the strongest visual influences on risk beliefs and ambiguity. Variations in contour focus and risk expression show promise for fostering appropriate levels of ambiguity.

Development and Testing of an Abbreviated Numeracy Scale: A Rasch Analysis Approach

Research has demonstrated that individual differences in numeracy may have important consequences for decision making. In the present paper, we develop a shorter, psychometrically improved measure of numeracy-the ability to understand, manipulate, and use numerical information, including probabilities. Across two large independent samples that varied widely in age and educational level, participants completed 18 items from existing numeracy measures. In Study 1, we conducted a Rasch analysis on the item pool and created an eight-item numeracy scale that assesses a broader range of difficulty than previous scales. In Study 2, we replicated this eight-item scale in a separate Rasch analysis using data from an independent sample. We also found that the new Rasch-based numeracy scale, compared with previous measures, could predict decision-making preferences obtained in past studies, supporting its predictive validity. In Study, 3, we further established the predictive validity of the Rasch-based numeracy scale. Specifically, we examined the associations between numeracy and risk judgments, compared with previous scales. Overall, we found that the Rasch-based scale was a better linear predictor of risk judgments than prior measures. Moreover, this study is the first to present the psychometric properties of several popular numeracy measures across a diverse sample of ages and educational level. We discuss the usefulness and the advantages of the new scale, which we feel can be used in a wide range of subject populations, allowing for a more clear understanding of how numeracy is associated with decision processes. Copyright © 2012 John Wiley & Sons, Ltd.

The influence of environmental hazard maps on risk beliefs, emotion, and health-related behavioral intentions

To test a theoretical explanation of how attributes of mapped environmental health hazards influence health-related behavioral intentions and how beliefs and emotion mediate the influences of attributes, 24 maps were developed that varied by four attributes of a residential drinking water hazard: level, proximity, prevalence, and density. In a factorial design, student participants (N = 446) answered questions about a subset of maps. Hazard level and proximity had the largest influences on intentions to test water and mitigate exposure. Belief in the problem's seriousness mediated attributes' influence on intention to test drinking water, and perceived susceptibility mediated the influence of attributes on intention to mitigate risk. Maps with carefully illustrated attributes of hazards may promote appropriate health-related risk beliefs, intentions, and behavior.

Subjective numeracy scale as a tool for assessing statistical numeracy in older adult populations

BACKGROUND

Statistical numeracy, necessary for making informed medical decisions, is reduced among older adults who make more decisions about their medical care and treatment than at any other stage of life. Objective numeracy scales are a source of anxiety among patients, heightened among older adults.

OBJECTIVE

We investigate the subjective numeracy scale as an alternative tool for measuring statistical numeracy with older adult samples.

METHODS

Numeracy was assessed using objective measures for 526 adults ranging in age from 18 to 93 years, and all participants provided subjective numeracy ratings.

RESULTS

Subjective numeracy correlated highly with objective measurements among oldest adults (70+ years; r = 0.51, 95% CI 0.32, 0.66), and for younger age groups. Subjective numeracy explained 33.2% of age differences in objective numeracy.

CONCLUSION

The subjective numeracy scale provides an effective tool for assessing statistical numeracy for broad age ranges and circumvents problems associated with objective numeracy measures.

The effect of narrative information in a publicly available patient decision aid for early-stage breast cancer

This study was designed to (1) evaluate the effect of narratives used in a popular, publicly available patient decision aid for early-stage breast cancer on hypothetical treatment decisions and attitudes toward the decision aid and (2) explore the moderating effects of participant numeracy, electronic health literacy and decision-making style. Two hundred women were asked to imagine that they had been diagnosed with early-stage breast cancer and viewed one of two versions of a video decision aid for early-stage breast cancer. The narrative version of the aid included stories from breast cancer survivors; the control version had no patient stories. After viewing the video decision aid, participants made a hypothetical treatment choice between lumpectomy with radiation and mastectomy, answered several questions about their decision, and evaluated the quality of the decision aid. Participants received $100 for completing the study. The two conditions differed in their motivations for the treatment decision and perceptions of the aid's trustworthiness and emotionality but showed no differences in preferences for surgical treatments or evaluations of the decision aid's quality. However, the impact of patient narratives was moderated by numeracy and electronic health literacy. Higher levels of numeracy were associated with decreased decisional confidence and lower ratings of trustworthiness for the decision aid in the narrative video condition but not in the control video condition. In contrast, higher levels of electronic health literacy were associated with increased decisional confidence and greater perceptions of trustworthiness and credibility of the decision aid in the narrative video condition but not the control video condition.

Low numeracy is associated with increased odds of 30-day emergency department or hospital recidivism for patients with acute heart failure

BACKGROUND

More than 25% of Medicare patients hospitalized for heart failure are readmitted within 30 days. The contributions of numeracy and health literacy to recidivism for patients with acute heart failure (AHF) are not known.

METHODS AND RESULTS

A cohort of patients with acute heart failure who presented to 4 emergency departments between January 2008 and September 2011. Research assistants administered subjective measures of numeracy and health literacy; 30-day follow-up was performed by phone interview. Recidivism was defined as any unplanned return to the emergency department or hospital within 30 days of the index emergency department visit for AHF. Multivariable logistic regression adjusting for patient age, sex, race, insurance status, hospital site, days eligible for recidivism, chronic kidney disease, abnormal hemoglobin, and low ejection fraction evaluated the relation between numeracy and health literacy with 30-day recidivism. Of the 709 patients included in the analysis, 390 (55%) had low numeracy skills and 258 (37%) had low literacy skills. Low numeracy was associated with increased odds of recidivism within 30 days (adjusted odds ratio, 1.41; 95% confidence interval, 1.00-1.98; P=0.048). For low health literacy, adjusted odds ratio of recidivism was 1.17 (95% confidence interval, 0.83-1.65; P=0.37).

CONCLUSIONS

Low numeracy was associated with greater odds of 30-day recidivism. Further investigation is warranted to determine whether addressing numeracy and health literacy may reduce 30-day recidivism for patients with acute heart failure.

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.

Research participants' high expectations of benefit in early-phase oncology trials: are we asking the right question?

PURPOSE

To determine whether patients' expectations of benefit in early-phase oncology trials depend on how patients are queried and to explore whether expectations are associated with patient characteristics.

PATIENTS AND METHODS

Participants were 171 patients in phase I or II oncology trials in the United States. After providing informed consent for a trial but before receiving the investigational therapy, participants answered questions about expectations of benefit. We randomly assigned participants to one of three groups corresponding to three queries about expectations: frequency type, belief type, or both. Main outcomes were differences in expectations by question type and the extent to which expectations were associated with demographic characteristics, numeracy, dispositional optimism, religiousness/spirituality, understanding of research, and other measures.

RESULTS

The belief-type group had a higher mean expectation of benefit (64.4 of 100) than the combination group (51.6; P = .01) and the frequency-type group (43.1; P < .001). Mean expectations in the combination and frequency groups were not significantly different (P = .06). Belief-type expectations were associated with a preference for nonquantitative information (r = -0.19; 95% CI, -0.19 to -0.36), knowledge about research (r = -0.21; 95% CI, -0.38 to -0.03), dispositional optimism (r = 0.20; 95% CI, 0.01 to 0.37), and spirituality (r = 0.22; 95% CI, 0.03 to 0.38). Frequency-type expectations were associated with knowledge about clinical research (r = -0.27; 95% CI, -0.27 to -0.51).

CONCLUSION

In early-phase oncology trials, patients' reported expectations of benefit differed according to how patients were queried and were associated with patient characteristics. These findings have implications for how informed consent is obtained and assessed.

Exploring objective and subjective numeracy at a population level: findings from the 2007 Health Information National Trends Survey (HINTS)

Numeracy is a critical component of decision making in health, and low numeracy may adversely affect risk comprehension, medical treatment, and health outcomes. Health researchers have developed objective and subjective measures of numeracy that potentially could be used for clinical or health research purposes. To examine the association between objective and subjective numeracy at a population level, data were obtained from the 2007 Health Information National Trends Survey, a health communication survey that collects data from a nationally representative sample of the U.S. population. Associations between items from 2 published subjective numeracy measures (STAT-Confidence Scale; Subjective Numeracy Scale) and a single published objective numeracy measure were examined with respect to one another and with respect to sociodemographic characteristics using a multivariate logistic regression model. Controlling for demographic covariates, both subjective numeracy measures were significantly associated with each other (p < .0001) and with objective numeracy (p < .0001). Compared with respondents who regarded themselves as low in subjective numeracy, those who regarded themselves as high in subjective numeracy had significantly higher odds of answering the objective numeracy question correctly (STAT-Confidence Scale OR = 1.42, CI [1.07, 1.90]; Subjective Numeracy Scale OR = 1.71, CI [1.28, 2.28]). However, the subjective measures performed poorly as diagnostic indicators of objective numeracy. Sensitivity and specificity for the STAT-Confidence Scale and the Subjective Numeracy Scale were 67%/49% and 50%/71%, respectively. More work is needed to elucidate the relation between objective and subjective numeracy, at the conceptual and empirical levels, and to develop more robust measures of subjective numeracy that can better discriminate between individuals with low and high objective numeracy.

Patients' preferences and priorities regarding colorectal cancer screening

BACKGROUND

US colorectal cancer screening guidelines for people at average risk for colorectal cancer endorse multiple screening options and recommend that screening decisions reflect individual patient preferences.

METHODS

The authors used the analytic hierarchy process (AHP) to ascertain decision priorities of people at average risk for colorectal cancer attending primary care practices in Rochester, New York; Birmingham, Alabama; and Indianapolis, Indiana. The analysis included 4 decision criteria, 3 subcriteria, and 10 options.

RESULTS

Four hundred eighty-four people completed the study; 66% were female, 49% were African American, 9% had low literacy skills, and 27% had low numeracy skills. Overall, preventing cancer was given the highest priority (mean priority 55%), followed by avoiding screening test side effects (mean priority 17%), minimizing false-positive test results (mean priority 15%), and the combined priority of screening frequency, test preparation, and the test procedure(s) (mean priority 14%). Hierarchical cluster analysis revealed 6 distinct priority groupings containing multiple instances of decision priorities that differed from the average value by a factor of 4 or more. More than 90% of the study participants fully understood the concepts involved, 79% met AHP analysis quality standards, and 88% were willing to use similar methods to help make important health care decisions.

CONCLUSION

These results highlight the need to facilitate incorporation of patient preferences into colorectal cancer screening decisions. The large number of study participants able and willing to perform the complex AHP analysis used for this study suggests that the AHP is a useful tool for identifying the patient-specific priorities needed to ensure that screening decisions appropriately reflect individual patient preferences.

Animated graphics for comparing two risks: a cautionary tale

Background

The 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.

Objective

To 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.

Methods

A 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.

Results

When 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.

Conclusions

Many 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.

The numeracy understanding in medicine instrument: a measure of health numeracy developed using item response theory

BACKGROUND

Health numeracy can be defined as the ability to understand and apply information conveyed with numbers, tables and graphs, probabilities, and statistics to effectively communicate with health care providers, take care of one's health, and participate in medical decisions.

OBJECTIVE

To develop the Numeracy Understanding in Medicine Instrument (NUMi) using item response theory scaling methods.

DESIGN

A 20-item test was formed drawing from an item bank of numeracy questions. Items were calibrated using responses from 1000 participants and a 2-parameter item response theory model. Construct validity was assessed by comparing scores on the NUMi to established measures of print and numeric health literacy, mathematic achievement, and cognitive aptitude.

PARTICIPANTS

Community and clinical populations in the Milwaukee and Chicago metropolitan areas.

RESULTS

Twenty-nine percent of the 1000 respondents were Hispanic, 24% were non-Hispanic white, and 42% were non-Hispanic black. Forty-one percent had no more than a high school education. The mean score on the NUMi was 13.2 (s = 4.6) with a Cronbach α of 0.86. Difficulty and discrimination item response theory parameters of the 20 items ranged from -1.70 to 1.45 and 0.39 to 1.98, respectively. Performance on the NUMi was strongly correlated with the Wide Range Achievement Test-Arithmetic (0.73, P < 0.001), the Lipkus Expanded Numeracy Scale (0.69, P < 0.001), the Medical Data Interpretation Test (0.75, P < 0.001), and the Wonderlic Cognitive Ability Test (0.82, P < 0.001). Performance was moderately correlated to the Short Test of Functional Health Literacy (0.43, P < 0.001).

LIMITATIONS

The NUMi was found to be most discriminating among respondents with a lower-than-average level of health numeracy.

CONCLUSIONS

The NUMi can be applied in research and clinical settings as a robust measure of the health numeracy construct.

Measuring pain impact versus pain severity using a numeric rating scale

BACKGROUND

Routine assessments of pain using an intensity numeric rating scale (NRS) have improved documentation, but have not improved clinical outcomes. This may be, in part, due to the failure of the NRS to adequately predict patients' preferences for additional treatment.

OBJECTIVE

To examine whether patients' illness perceptions have a stronger association with patient treatment preferences than the pain intensity NRS.

DESIGN

Single face-to-face interview.

PARTICIPANTS

Outpatients with chronic, noncancer, musculoskeletal pain.

MAIN MEASURES

Experience of pain was measured using 18 illness perception items. Factor analysis of these items found that five factors accounted for 67.1% of the variance; 38% of the variance was accounted for by a single factor labeled "pain impact." Generalized linear models were used to examine how NRS scores and physical function compare with pain impact in predicting preferences for highly effective/high-risk treatment.

KEY RESULTS

Two hundred forty-nine subjects agreed to participate. Neither NRS nor functioning predicted patient preference (NRS: χ2 = 1.92, df = 1, p = 0.16, physical functioning: χ2 = 2.48, df = 1, p = 0.11). In contrast, pain impact was significantly associated with the preference for a riskier/more effective treatment after adjusting for age, comorbidity, efficacy of current medications and numeracy (χ2 = 4.40, df = 1, p = 0.04).

CONCLUSIONS

Tools that measure the impact of pain may be a more valuable screening instrument than the NRS. Further research is now needed to determine if measuring the impact of pain in clinical practice is more effective at triggering appropriate management than more restricted measures of pain such as the NRS.

The influence of mapped hazards on risk beliefs: a proximity-based modeling approach

Interview findings suggest perceived proximity to mapped hazards influences risk beliefs when people view environmental hazard maps. For dot maps, four attributes of mapped hazards influenced beliefs: hazard value, proximity, prevalence, and dot patterns. In order to quantify the collective influence of these attributes for viewers' perceived or actual map locations, we present a model to estimate proximity-based hazard or risk (PBH) and share study results that indicate how modeled PBH and map attributes influenced risk beliefs. The randomized survey study among 447 university students assessed risk beliefs for 24 dot maps that systematically varied by the four attributes. Maps depicted water test results for a fictitious hazardous substance in private residential wells and included a designated "you live here" location. Of the nine variables that assessed risk beliefs, the numerical susceptibility variable was most consistently and strongly related to map attributes and PBH. Hazard value, location in or out of a clustered dot pattern, and distance had the largest effects on susceptibility. Sometimes, hazard value interacted with other attributes, for example, distance had stronger effects on susceptibility for larger than smaller hazard values. For all combined maps, PBH explained about the same amount of variance in susceptibility as did attributes. Modeled PBH may have utility for studying the influence of proximity to mapped hazards on risk beliefs, protective behavior, and other dependent variables. Further work is needed to examine these influences for more realistic maps and representative study samples.

Measuring Risk Literacy: The Berlin Numeracy Test

We introduce the Berlin Numeracy Test, a new psychometrically sound instrument that quickly assesses statistical numeracy and risk literacy. We present 21 studies (n=5336) showing robust psychometric discriminability across 15 countries (e.g., Germany, Pakistan, Japan, USA) and diverse samples (e.g., medical professionals, general populations, Mechanical Turk web panels). Analyses demonstrate desirable patterns of convergent validity (e.g., numeracy, general cognitive abilities), discriminant validity (e.g., personality, motivation), and criterion validity (e.g., numerical and non-numerical questions about risk). The Berlin Numeracy Test was found to be the strongest predictor of comprehension of everyday risks (e.g., evaluating claims about products and treatments; interpreting forecasts), doubling the predictive power of other numeracy instruments and accounting for unique variance beyond other cognitive tests (e.g., cognitive reflection, working memory, intelligence). The Berlin Numeracy Test typically takes about three minutes to complete and is available in multiple languages and formats, including a computer adaptive test that automatically scores and reports data to researchers (http://www.riskliteracy.org). The online forum also provides interactive content for public outreach and education, and offers a recommendation system for test format selection. Discussion centers on construct validity of numeracy for risk literacy, underlying cognitive mechanisms, and applications in adaptive decision support.

Physicians' shared decision-making behaviors in attention-deficit/hyperactivity disorder care

OBJECTIVES

To describe the amount of shared decision-making (SDM) behavior exhibited during treatment-planning encounters for children newly diagnosed as having attention-deficit/hyperactivity disorder and to explore relationships between participant characteristics and the amount of SDM.

DESIGN

Prospective cohort study.

SETTING

Seven community-based primary care pediatric practices in the Cincinnati, Ohio; northern Kentucky; and southeast Indiana regions from October 5, 2009, through August 9, 2010.

PARTICIPANTS

Ten pediatricians and 26 families with a 6- to 10-year-old child newly diagnosed as having attention-deficit/hyperactivity disorder.

OUTCOME MEASURE

The amount of SDM behavior exhibited during videorecorded encounters, as coded by 2 independent raters using the validated Observing Patient Involvement (OPTION) scale, which was adapted for use in pediatric settings and produces a score ranging from 0 (no parental involvement) to 100 (maximal parental involvement).

RESULTS

Treatment decisions focused on initiation of medication treatment. The mean (SD) total OPTION score was 28.5 (11.7). More SDM was observed during encounters involving families with white vs nonwhite children (adjusted mean difference score, 14.9; 95% confidence interval [CI], 10.2-19.6; P < .001), private vs public health insurance coverage (adjusted mean difference score, 15.1; 11.2-19.0; P < .001), mothers with at least some college education vs high school graduate or less (adjusted mean difference score, 12.3; 7.2-17.4; P < .001), and parents who did not screen positive for serious mental illness vs those who did (adjusted mean difference score, 15.0; 11.9-18.1; P < .001).

CONCLUSIONS

Low levels of SDM were observed. Exploratory analyses identified potential disparities and barriers. Interventions may be needed to foster SDM with all parents, especially those of nonwhite race, of lower socioeconomic status, of lower educational level, and with serious mental illness.

Patient decision making about organ quality in liver transplantation

It is challenging to discuss the use of high-risk organs with patients, in part because of the lack of information about how patients view this topic. This study was designed to determine how patients think about organ quality and to test formats for risk communication. Semistructured interviews of 10 patients on the waiting list revealed limited understanding about the spectrum of organ quality and a reluctance to consider anything but the best organs. A computerized quantitative survey was then conducted with an interactive graph to elicit the risk of graft failure that patients would accept. Fifty-eight percent of the 95 wait-listed patients who completed the survey would accept only organs with a risk of graft failure of 25% or less at 3 years, whereas 18% would accept only organs with the lowest risk possible (19% at 3 years). Risk tolerance was increased when the organ quality was presented relative to average organs rather than the best organs and when feedback was provided about the implications for organ availability. More than three-quarters of the patients reported that they wanted an equal or dominant role in organ acceptance decisions. Men tended to prefer lower risk organs (mean acceptable risk = 29%) in comparison with women (mean acceptable risk = 35%, P = 0.04), but risk tolerance was not associated with other demographic or clinical characteristics (eg, the severity of liver disease). In summary, patients want to be involved in decisions about organ quality. Patients' risk tolerance varies widely, and their acceptance of high-risk organs can be facilitated if we present the risks of graft failure with respect to average organs and provide feedback about the implications for organ availability.

Short, subjective measures of numeracy and general health literacy in an adult emergency department

OBJECTIVES

The objective was to evaluate the reliability and validity of brief subjective measures of numeracy and general health literacy in the adult emergency department (ED) setting.

METHODS

A convenience sample of adult ED patients completed subjective measures of general health literacy (Short Literacy Survey [SLS]) and numeracy (Subjective Numeracy Scale [SNS]). These patients also completed two objective tests of literacy (the Short Test of Functional Health Literacy in Adults [S-TOFHLA] and the Rapid Estimate of Adult Literacy in Medicine [REALM]) and an objective test of numeracy (Wide Range Achievement Test-4 [WRAT4]). Internal reliability of the subjective measures was assessed using Cronbach's alpha. Construct validity of the subjective measures was assessed by correlating them against the S-TOFHLA, REALM, and WRAT4, using Spearman's rank correlation coefficients, receiver operating characteristics (ROC) curves, and hierarchical, multiple linear regression with adjustment for patient age, sex, race, and education.

RESULTS

The median age of the 207 patients surveyed was 46 years (interquartile range [IQR] = 32 to 59 years); 27% were African American. Sixty-one percent of patients reported that their highest level of education was high school or below. As measured by the S-TOFHLA and REALM, most patients had adequate literacy levels (89% and 80%, respectively), while 44% of patients had below average numeracy skills on the WRAT4. The median SLS score was 14 (IQR = 12 to 15) on a scale of 3 to 15; the median SNS score was 36 (IQR = 30 to 42) on a scale of 6 to 48. The SLS and SNS had good internal reliability, with Cronbach's alphas of 0.74 and 0.82, respectively. The SLS Spearman's rank order correlation coefficient was 0.33 (95% confidence interval [CI] = 0.20 to 0.45) for the S-TOFHLA, with a standardized beta coefficient of 0.36 (p < 0.05) after adjustment for patient demographics. The SLS correlation coefficient was 0.26 (95% CI = 0.13 to 0.38) for the REALM, with a standardized beta coefficient of 0.38 (p < 0.05) after adjustment for patient demographics. The area under the ROC curve (AUC) for the SLS was 0.74 (95% CI = 0.68 to 0.80) when compared to the S-TOFHLA and 0.72 (95% CI = 0.65 to 0.78) when compared to the REALM. The SNS predicted numeracy well, with a correlation coefficient of 0.57 (95% CI = 0.47 to 0.65) for the WRAT4, a standardized beta coefficient of 0.30 (p < 0.05) after adjustment for patient demographics, and an AUC of 0.77 (95% CI = 0.70 to 0.82).

CONCLUSIONS

The SNS and SLS are reliable, valid tests that can be used to rapidly estimate general health literacy and numeracy skill levels in adult ED patients. Continuing work is needed to establish their ability to predict clinical outcomes.

Bridging the digital divide in diabetes: family support and implications for health literacy

Abstract Background: Patient web portals (PWPs) offer patients remote access to their medical record and communication with providers. Adults with health literacy limitations are less likely to access and use health information technology (HIT), including PWPs. In diabetes, PWP use has been associated with patient satisfaction, patient-provider communication, and glycemic control.

METHODS

Using mixed methods, we explored the relationships between health literacy, numeracy, and computer literacy and the usage of a PWP and HIT. Participants (N=61 adults with type 2 diabetes) attended focus groups and completed surveys, including measures of health literacy, numeracy, and computer anxiety (an indicator of computer literacy) and frequency of PWP and HIT use.

RESULTS

Computer literacy was positively associated with health literacy (r=0.41, P<0.001) and numeracy (r=0.35, P<0.001), but health literacy was not associated with numeracy. Participants with limited health literacy (23%), numeracy (43%), or computer literacy (25%) were no less likely to access PWPs or HIT, but lower health literacy was associated with less frequent use of a computer to research diabetes medications or treatments. In focus groups, participants spontaneously commented on family support when accessing and using PWPs or HIT for diabetes management.

CONCLUSIONS

Participants reported family members facilitated access and usage of HIT, taught them usage skills, and acted as online delegates. Participant statements suggest family members may bridge the HIT "digital divide" in diabetes by helping adults access a PWP or HIT for diabetes management.

Cool but counterproductive: interactive, Web-based risk communications can backfire

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.

A new adaptive testing algorithm for shortening health literacy assessments

Background

Low health literacy has a detrimental effect on health outcomes, as well as ability to use online health resources. Good health literacy assessment tools must be brief to be adopted in practice; test development from the perspective of item-response theory requires pretesting on large participant populations. Our objective was to develop a novel classification method for developing brief assessment instruments that does not require pretesting on large numbers of research participants, and that would be suitable for computerized adaptive testing.

Methods

We present a new algorithm that uses principles of measurement decision theory (MDT) and Shannon's information theory. As a demonstration, we applied it to a secondary analysis of data sets from two assessment tests: a study that measured patients' familiarity with health terms (52 participants, 60 items) and a study that assessed health numeracy (165 participants, 8 items).

Results

In the familiarity data set, the method correctly classified 88.5% of the subjects, and the average length of test was reduced by about 50%. In the numeracy data set, for a two-class classification scheme, 96.9% of the subjects were correctly classified with a more modest reduction in test length of 35.7%; a three-class scheme correctly classified 93.8% with a 17.7% reduction in test length.

Conclusions

MDT-based approaches are a promising alternative to approaches based on item-response theory, and are well-suited for computerized adaptive testing in the health domain.

The impact of physicians' reactions to uncertainty on patients' decision satisfaction

RATIONALE

Patients' and physicians' response to uncertainty may affect decision outcomes. The purpose of this study was to explore the impact of patients' and physicians' reactions to uncertainty on patients' satisfaction with breast health decisions.

METHODS

Seventy-five women facing breast cancer prevention or treatment decisions and five surgeons were recruited from a breast health centre. Patients' and physicians' anxiety from uncertainty was assessed using the Physicians' Reactions to Uncertainty Scale; wording was slightly modified for patients to ensure the scale was applicable. Patients' decision satisfaction was assessed 1-2 weeks after their appointment. A mixed-effects logistic regression model was used to assess associations between patients' and providers' anxiety from uncertainty and patients' decision satisfaction. A provider-specific random effects term was included in the model to account for correlation among patients treated by the same provider.

RESULTS

Patients' decision satisfaction was associated with physicians' anxiety from uncertainty (beta = 0.92, P < 0.01), but not with patients' anxiety from uncertainty (beta = -0.18, P > 0.27).

CONCLUSIONS

This study suggests that physicians' reactions to uncertainty may have an effect on decision satisfaction in patients. More research is needed to confirm this relationship and to determine how to help patient-provider dyads to manage the uncertainty that is inherent in most cancer decisions.

Using a familiar risk comparison within a risk ladder to improve risk understanding by low numerates: a study of visual attention

Previous experimental research provides evidence that a familiar risk comparison within a risk ladder is understood by low- and high-numerate individuals. It especially helps low numerates to better evaluate risk. In the present study, an eye tracker was used to capture individuals' visual attention to a familiar risk comparison, such as the risk associated with smoking. Two parameters of information processing-efficiency and level-were derived from visual attention. A random sample of participants from the general population (N= 68) interpreted a given risk level with the help of the risk ladder. Numeracy was negatively correlated with overall visual attention on the risk ladder (r(s) =-0.28, p= 0.01), indicating that the lower the numeracy, the more the time spent looking at the whole risk ladder. Numeracy was positively correlated with the efficiency of processing relevant frequency (r(s) = 0.34, p < 0.001) and relevant textual information (r(s) = 0.34, p < 0.001), but not with the efficiency of processing relevant comparative information and numerical information. There was a significant negative correlation between numeracy and the level of processing of relevant comparative risk information (r(s) =-0.21, p < 0.01), indicating that low numerates processed the comparative risk information more deeply than the high numerates. There was no correlation between numeracy and perceived risk. These results add to previous experimental research, indicating that the smoking risk comparison was crucial for low numerates to evaluate and understand risk. Furthermore, the eye-tracker method is promising for studying information processing and improving risk communication formats.

Women's interest in taking tamoxifen and raloxifene for breast cancer prevention: response to a tailored decision aid

Although tamoxifen can prevent primary breast cancer, few women use it as a preventive measure. A second option, raloxifene, has recently been approved. The objective of the study was to determine women's interest in tamoxifen and raloxifene after reading a decision aid (DA) describing the risks and benefits of each medication. Women with 5-year risk of breast cancer ≥ 1.66 from two large health maintenance organizations were randomized to receive a DA versus usual care. After reading an on-line DA that discussed the risks and benefits of tamoxifen and raloxifene, women completed measures of risk perception, decisional conflict, behavioral intentions, and actual behavior related to tamoxifen and raloxifene. 3 months following the intervention, 8.1% of participants had looked for additional information about breast cancer prevention drugs, and 1.8% had talked to their doctor about tamoxifen and/or raloxifene. The majority, 54.7%, had decided to not take either drug, 0.5% had started raloxifene, and none had started tamoxifen. Participants were not particularly worried about taking tamoxifen or raloxifene and did not perceive significant benefits from taking these drugs. Over 50% did not perceive a change in their risk of getting breast cancer if they took tamoxifen or raloxifene. After reading a DA about tamoxifen and raloxifene, few women were interested in taking either breast cancer prevention drug.

Health literacy, numeracy, and interpretation of graphical breast cancer risk estimates

OBJECTIVE

Health literacy and numeracy are necessary to understand health information and to make informed medical decisions. This study explored the relationships among health literacy, numeracy, and ability to accurately interpret graphical representations of breast cancer risk.

METHODS

Participants (N=120) were recruited from the Facing Our Risk of Cancer Empowered (FORCE) membership. Health literacy and numeracy were assessed. Participants interpreted graphs depicting breast cancer risk, made hypothetical treatment decisions, and rated preference of graphs.

RESULTS

Most participants were Caucasian (98%) and had completed at least one year of college (93%). Fifty-two percent had breast cancer, 86% had a family history of breast cancer, and 57% had a deleterious BRCA gene mutation. Mean health literacy score was 65/66; mean numeracy score was 4/6; and mean graphicacy score was 9/12. Education and numeracy were significantly associated with accurate graph interpretation (r=0.42, p<0.001 and r=0.65, p<0.001, respectively). However, after adjusting for numeracy in multivariate linear regression, education added little to the prediction of graphicacy (r(2)=0.41 versus 0.42, respectively).

CONCLUSION

In our highly health-literate population, numeracy was predictive of graphicacy.

PRACTICE IMPLICATIONS

Effective risk communication strategies should consider the impact of numeracy on graphicacy and patient understanding.

Effects of game-like interactive graphics on risk perceptions and decisions

BACKGROUND

Many patients have difficulty interpreting risks described in statistical terms as percentages. Computer game technology offers the opportunity to experience how often an event occurs, rather than simply read about its frequency.

OBJECTIVE

. To assess effects of interactive graphics on risk perceptions and decisions.

DESIGN

. Electronic questionnaire. Participants and setting. Respondents (n = 165) recruited online or at an urban hospital. Intervention. Health risks were illustrated by either static graphics or interactive game-like graphics. The interactive search graphic was a grid of squares, which, when clicked, revealed stick figures underneath. Respondents had to click until they found a figure affected by the disease. Measurements. Risk feelings, risk estimates, intention to take preventive action.

RESULTS

. Different graphics did not affect mean risk estimates, risk feelings, or intention. Low-numeracy participants reported significantly higher risk feelings than high-numeracy ones except with the interactive search graphic. Unexpectedly, respondents reported stronger intentions to take preventive action when the intention question followed questions about efficacy and disease severity than when it followed perceived risk questions (65% v. 34%; P < 0.001). When respondents reported risk feelings immediately after using the search graphic, the interaction affected perceived risk (the longer the search to find affected stick figures, the higher the risk feeling: ρ = 0.57; P = 0.009). Limitations. The authors used hypothetical decisions.

CONCLUSIONS

. A game-like graphic that allowed consumers to search for stick figures affected by disease had no main effect on risk perception but reduced differences based on numeracy. In one condition, the game-like graphic increased concern about rare risks. Intentions for preventive action were stronger with a question order that focused first on efficacy and disease severity than with one that focused first on perceived risk.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

PRACTICE IMPLICATIONS

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

The benefits of discussing adjuvant therapies one at a time instead of all at once

Breast cancer patients must often decide between multiple adjuvant therapy options to prevent cancer recurrence. Standard practice, as implemented in current decision support tools, is to present information about all options simultaneously, but psychology research suggests that sequential decision processes might improve decision making. We tested whether asking women to consider hormonal therapy and chemotherapy separately would improve women's risk knowledge and/or affect treatment intentions. We conducted an Internet-administered experimental survey of a demographically diverse sample of 1,781 women ages 40-74. Participants were randomized to experience a standard, comprehensive decision process versus sequential (one at a time) decisions regarding adjuvant therapy options for a hypothetical breast cancer patient with an estrogen receptor-positive (ER+) tumor. We assessed comprehension of key statistics, perceptions of treatment effectiveness, and perceived interest in adjuvant chemotherapy, as well as participants' numeracy levels. When participants made sequential decisions, they demonstrated greater comprehension of decision-relevant risk statistics, as compared to when they made decisions all at once (all P's < 0.001). Among higher-numeracy participants, those making sequential decisions were less interested in chemotherapy (P < 0.001). Lower-numeracy participants who considered all options simultaneously were insensitive to the degree of risk reduction, but those who made sequential decisions were sensitive (P = 0.03). In conclusion, presenting adjuvant therapy options sequentially improves women's comprehension of incremental treatment benefit and increases less numerate women's sensitivity to the magnitude of the achievable risk reduction over standard, all at once approaches. Sequential approaches to adjuvant therapy decisions may reduce use of chemotherapy among those at low risk for recurrence.

Communicating uncertainty can lead to less decision satisfaction: a necessary cost of involving patients in shared decision making?

BACKGROUND

Given the large number of interventions of uncertain effectiveness, research on communicating uncertainty is needed to examine its impact on patients' health decisions.

OBJECTIVE

To examine physicians' communication of uncertainty and its impact on patients' decisions and decision satisfaction.

DESIGN, SETTING, AND PARTICIPANTS

Participants included female patients seen in a breast health centre whose physicians were discussing a decision with them, with no clear 'best' choice based on outcome evidence.

MAIN VARIABLES

Decision communication was measured using the OPTION scale, a measure of the degree to which physicians involve patients in a decision-making process. One-to-two weeks after the discussion, patients reported their satisfaction with the decision-making process and their decision. Decisions were verified in medical charts with patient consent.

RESULTS

Seventy-five women agreed to participate (94% response rate). The mean translated score of the OPTION scale was 68.0 (SD 18.3), but only 33.2 (SD 19.1) for the uncertainty items. Among cancer patients, communicating uncertainty was negatively related to decision satisfaction (P < 0.002), and there was an interaction between patient involvement in decisions and communicating uncertainty in relation to patients' decision satisfaction (P < 0.03).

DISCUSSION

Communicating scientific uncertainty might lead to less decision satisfaction among women facing cancer treatment decisions; this could be a natural outcome of the decision making process. Involving patients in decisions might help them tolerate uncertainty.

CONCLUSION

Future studies should consider assessing other outcomes (e.g. knowledge, physician support) of the decision making process. There may be trade-offs between acknowledging uncertainty and immediate decision satisfaction.

Presenting research risks and benefits to parents: does format matter?

BACKGROUND

Several studies suggest that many parents and research participants have poor understanding of the elements of consent, particularly the risks and benefits. However, some data suggest that the format and framing of research risks and benefits may be an important determinant of subject understanding. We examined the effect of tabular and graphical presentation of risks and benefits on parents' understanding of a research study.

METHODS

Parents of children scheduled to undergo an elective surgical procedure (n = 408) were randomized to receive information about the risks and benefits of a sham study of postoperative pain control using text, tables, or pictographs and then completed a questionnaire to examine their gist (essential) and verbatim (actual) understanding of the information. Parent demographics were recorded and their literacy and numeracy skills measured.

RESULTS

Parents randomized to receive information using tables or pictographs had significantly (P < 0.025) greater gist and verbatim understanding than did parents who received the information using standard text. Tables and pictographs were also superior to text in promoting understanding among parents with low numeracy and literacy skills.

CONCLUSIONS

Many parents and patients have difficulty in assimilating and interpreting risk/benefit information for both research and treatment. This is due, in part, to the manner in which risks and benefits are communicated and to the literacy and numeracy abilities of the individual. The results of this study suggest a simple and practical method for enhancing understanding of risk/benefit statistics for parents with varying numeracy and literacy skills.

The effect of format on parents' understanding of the risks and benefits of clinical research: a comparison between text, tables, and graphics

There is a paucity of information regarding the optimal method of presenting risk/benefit information to parents of pediatric research subjects. This study, therefore, was designed to examine the effect of different message formats on parents' understanding of research risks and benefits. An Internet-administered survey was completed by 4,685 parents who were randomized to receive risk/benefit information about a study of pediatric postoperative pain control presented in different message formats (text, tables, and pictographs). Survey questions assessed participants' gist and verbatim understanding of the information and their perceptions of the risks and benefits. Pictographs were associated with significantly (p < .05) greater likelihood of adequate gist and verbatim understanding compared with text and tables regardless of the participants' numeracy. Parents who received the information in pictograph format perceived the risks to be lower and the benefits to be higher compared with the other formats (p < .001). Furthermore, compared with text and tables, pictographs were perceived as more "effective," "helpful," and "trustworthy" in presenting risk/benefit information. These results underscore the difficulties associated with presenting risk/benefit information for clinical research but suggest a simple method for enhancing parents' informed understanding of the relevant statistics.

Effect of various risk/benefit trade-offs on parents' understanding of a pediatric research study

OBJECTIVES

Informed decision-making requires that parents and research subjects understand the risks and benefits of a study, yet research suggests that comprehension of these elements is often poor. This study was designed to examine the effect of factors including manipulation of risk/benefit trade-offs, numeracy, and sociodemographics on parents' understanding of risks and benefits.

METHODS

A total of 4685 parents completed an Internet survey in which they were randomly assigned to receive information about the risks and benefits of a hypothetical pain treatment study presented in 1 of 4 scenarios. Parents' gist (essential) and verbatim (exact) understanding and their perceptions of the risks and benefits were compared across scenarios. The effects of parental sociodemographics and numeracy were also examined.

RESULTS

Participants who were randomly assigned to consider a research study that offered the possibility of improved outcomes had higher gist and verbatim understanding of the information than participants who were considering studies that offered only reductions in the risk for adverse effects. Furthermore, these parents perceived the risks of the study to be significantly lower compared with the scenarios that offered the same risks but less benefit. White race, college education, and higher numeracy all were associated significantly with improved gist and verbatim understanding.

CONCLUSIONS

Research studies that offer only improved outcomes to participants may be evaluated more thoroughly than those that offer only reduced risks, and individual characteristics significantly moderate parents' ability to comprehend risk/benefit information. These results are important toward developing strategies to improve the ways in which risks and benefits are communicated to parents and research subjects.

A demonstration of ''less can be more'' in risk graphics

BACKGROUND

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.

OBJECTIVE

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.

DESIGN

. Randomized experimental manipulation of risk graphics shown included in Internet-administered survey vignettes about adjuvant therapy decisions for breast cancer patients with ER + tumors.

PARTICIPANTS

Demographically diverse, stratified random samples of women ages 40 to 74 y recruited from an Internet research panel.

INTERVENTION

Participants were randomized to view either pictographs (icon arrays) that displayed all 4 possible outcomes or pictographs that showed only survival outcomes.

MEASUREMENTS

Comprehension of key statistics, task completion times, graph evaluation ratings, and perceived interest in adjuvant chemotherapy.

RESULTS

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).

LIMITATIONS

Studies used general public samples; actual patients may process risk information differently.

CONCLUSIONS

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.

Genetic testing and risk interpretation: How do women understand lifetime risk results?

Genetic screening for BRCA1 and BRCA2 gives women the opportunity for early detection, surveillance, and intervention. One key feature of genetic testing and counseling is the provision of personal lifetime risk. However, little attention has been paid to how women interpret lifetime risk information, despite the fact that they base screening, treatment and family planning decisions on such information. To study this vital issue, we set out to test the ability of women to choose the most appropriate interpretation of National Cancer Institute’s (NCI) message about lifetime risk of developing cancer for a woman with altered BRCA1 and BRCA2 genes. Participants included 277 women who had not undergone genetic testing or had cancer and 207 women who had undergone genetic testing or had cancer. Over 50% of the women who had not undergone genetic testing or had cancer and 40% of those who had undergone genetic testing or had cancer misunderstood NCI’s information. Furthermore, in line with a growing body of research, we found that high numeracy level (objective or subjective) is positively associated with a woman’s ability to correctly interpret NCI’s message.

Attitudes of the American public toward organ donation after uncontrolled (sudden) cardiac death

Concerns about public support for organ donation after cardiac death have hindered expansion of this practice, particularly rapid organ recovery in the context of uncontrolled (sudden) cardiac death (uDCD). A nationally representative Internet-based panel was provided scenarios describing donation in the context of brain death, controlled cardiac death and uncontrolled cardiac death. Participants were randomized to receive questions about trust in the medical system before or after the rapid organ recovery scenario. Among 1631 panelists, 1049 (64%) completed the survey. Participants expressed slightly more willingness to donate in the context of controlled and uncontrolled cardiac death than after brain death (70% and 69% vs. 66%, respectively, p < 0.01). Eighty percent of subjects (95% CI 77-84%) would support having a rapid organ recovery program in their community, though 83% would require family consent or a signed donor card prior to invasive procedures for organ preservation. The idea of uDCD slightly decreased trust in the medical system from 59% expressing trust to 51% (p = 0.02), but did not increase belief that a signed donor card would interfere with medical care (28% vs. 32%, p = 0.37). These findings provide support for the careful expansion of uDCD, albeit with formal consent prior to organ preservation.