Who profits from visual aids: overcoming challenges in people's understanding of risks [corrected]

Understandability of Patient Information Booklets for Patients with Cancer

The improvement of health literacy in general and the information of individual patient is a major concern of the German national cancer plan and similar initiatives in other western countries. The aim of our study was to assess the readability and understandability of information booklets for cancer patients available at German Web sites. A support vector machine (SVM) was used to discriminate between laymen- and expert-centric patient information booklets about nine most common tumor types. All booklets had to be available for free at the Internet. A total of 52 different patient booklets were downloaded and assessed. Overall, the assessment of all booklets showed that an understandability level L of 4.6 and therefore increased medical background knowledge is required to understand a random text selected from the sample. The assessed information booklets on cancer show very limited suitability for laymen. We were able to demonstrate that a medical background is necessary to understand the examined booklets. The current study highlights the need to create information material adjusted to the needs of laymen. Assessing understandability before publication, especially for laymen with low health literacy, could ensure the suitability and thus quality of the information material.

Impact of Information Presentation Format on Preference for Total Knee Replacement Surgery

OBJECTIVE

Patients have a poor understanding of outcomes related to total knee replacement (TKR) surgery, with most patients underestimating the potential benefits and overestimating the risk of complications. In this study, we sought to compare the impacts of descriptive information alone or in combination with an icon array, experience condition (images), or spinner on participants' preference for TKR.

METHODS

A total of 648 members of an online arthritis network were randomized to 1 of 4 outcome presentation formats: numeric only, numeric with an icon array, numeric with a set of 50 images, or numeric with a functional spinner. Preferences for TKR were measured before and immediately after viewing the outcome information using an 11-point numeric rating scale. Knowledge was assessed by asking participants to report the frequency of each outcome.

RESULTS

Participants randomized to the icon array, images, and spinner had stronger preferences for TKR (after controlling for baseline preferences) compared to those viewing the numeric only format (P < 0.05 for all mean differences). Knowledge scores were highest in participants randomized to the icon array; however, knowledge did not mediate the association between format and change in preference for TKR.

CONCLUSION

Decision support at the point-of-care is being increasingly recognized as a vital component of care. Our findings suggest that adding graphic information to descriptive statistics strengthens preferences for TKR. Although experience formats using images may be too complex to use in clinical practice, icon arrays and spinners may be a viable and easily adaptable decision aid to support communication of probabilistic information.

Designing Graphs that Promote Both Risk Understanding and Behavior Change

Graphs show promise for improving communications about different types of risks, including health risks, financial risks, and climate risks. However, graph designs that are effective at meeting one important risk communication goal (promoting risk-avoidant behaviors) can at the same time compromise another key goal (improving risk understanding). We developed and tested simple bar graphs aimed at accomplishing these two goals simultaneously. We manipulated two design features in graphs, namely, whether graphs depicted the number of people affected by a risk and those at risk of harm ("foreground+background") versus only those affected ("foreground-only"), and the presence versus absence of simple numerical labels above bars. Foreground-only displays were associated with larger risk perceptions and risk-avoidant behavior (i.e., willingness to take a drug for heart attack prevention) than foreground+background displays, regardless of the presence of labels. Foreground-only graphs also hindered risk understanding when labels were not present. However, the presence of labels significantly improved understanding, eliminating the detrimental effect of foreground-only displays. Labels also led to more positive user evaluations of the graphs, but did not affect risk-avoidant behavior. Using process modeling we identified mediators (risk perceptions, understanding, user evaluations) that explained the effect of display type on risk-avoidant behavior. Our findings contribute new evidence to the graph design literature: unlike what was previously feared, we demonstrate that it is possible to design foreground-only graphs that promote intentions for behavior change without a detrimental effect on risk understanding. Implications for the design of graphical risk communications and decision support are discussed.

Improving Understanding of Diagnostic Test Outcomes

BACKGROUND

Understanding diagnostic test outcomes requires determining the positive predictive value (PPV) of the test, which most laypeople and medical professionals struggle to do. Despite advances found with frequency formats and visual aids, less than 40% of people can typically identify this value. This study tests the impact of using congruent reference classes in problem-question pairings, evaluates the role of numeracy, and assesses how diagnostic value estimates affect the reported likelihood to use the test.

METHOD

A 3 × 2, Pairing (congruent test-focus, congruent condition-focus, incongruent) × Response Format (frequency, percentage) mixed design experiment was conducted, in which participants answered diagnostic questions about 7 medical problems presented in a format focusing either on the reference class of those who test positive or those who have the condition. Answer accuracy, numeracy, and ratings of likelihood to use estimates were assessed.

RESULTS

Focusing on the congruent test reference class allowed 87% of participants to consistently identify the PPV, and focusing on the congruent condition reference class led 63% of participants to consistently identify the sensitivity (SEN). Aligning reference classes was especially beneficial for those with lower numeracy, increasing accuracy on problems from 21% for incongruent pairings to 66% for congruent pairings. Ratings of likelihood to use the test were closely tied to participants' estimates of diagnostic values, regardless of the accuracy of those estimates.

CONCLUSIONS

Although often overlooked, a straightforward mapping of reference classes from the relevant diagnostic information to the question of interest reduces confusion and substantially increases accuracy in estimates of diagnostic values. These findings can be used to strengthen training in the assessment of uncertainties associated with medical test results.

Limitations of the S-TOFHLA in measuring poor numeracy: a cross-sectional study

Background

Although the Short Test of Functional Health Literacy in Adults (S-TOFHLA) is widely used, misidentification of individuals with low health literacy (HL) in specific HL dimensions, like numeracy, is a concern. We examined the degree to which individuals scored as “adequate” HL on the S-TOFHLA would be considered as having low HL by two additional numerical measures.

Methods

English-speaking adults aged 45–75 years were recruited from a large, urban academic medical center and a community foodbank in the United States. Participants completed the S-TOFHLA, the Subjective Numeracy Scale (SNS), and the Graphical Literacy Measure (GL), an objective measure of a person’s ability to interpret numeric information presented graphically. Established cut-points or a median split classified participants and having high and low numeracy.

Results

Participants (n = 187), on average were: aged 58 years; 63% female; 70% Black/African American; and 45% had a high school degree or less. Of those who scored “adequate” on the S-TOFHLA, 50% scored low on the SNS and 40% scored low on GL. Correlation between the S-TOFHLA and the SNS Total was moderate (r = 0.22, n = 186, p = 0.01), while correlation between the S-TOFHLA and the GL Total was large (r = 0.53, n = 187, p ≤ 0.01).

Conclusions

Findings suggest that the S-TOFHLA may not capture an individuals’ HL in the dimension of numeracy. Efforts are needed to develop more encompassing and practical strategies for identifying those with low HL for use in research and clinical practice.

Trial registration

NCT02151032 (retrospectively registered: May 30, 2014).

Impact of numeracy on understanding of prostate cancer risk reduction in PSA screening

Prostate-specific antigen (PSA) screening for prostate cancer in men of average risk remains controversial. Patients' ability to incorporate risk reduction data into their decision-making may depend on their numeracy. We assessed the impact of patients' numeracy on their understanding of the risk reduction benefits of PSA screening. Men attending a general internal medicine clinic were invited to complete a survey. Four versions of the survey each included a three-item numeracy test and PSA risk reduction data, framed one of four ways: absolute (ARR) versus relative risk reduction (RRR), with or without baseline risk (BR). Respondents were asked to adjust their perceived risk of prostate-cancer mortality using the data presented. Accuracy of risk reduction was evaluated relative to how risk data were framed. Among a total of 200 respondents, a majority incorrectly answered one or more of the numeracy items. Overall accuracy of risk adjustment was only 20%. Accuracy varied with data framing: when presented with RRR, respondents were 13% accurate without BR and 31% accurate with BR; when presented with ARR, they were 0% accurate without BR and 35% accurate with BR. Including BR data significantly improved accuracy for both RRR (P = 0.03) and ARR groups (P < 0.01). Accuracy was significantly related to numeracy; numeracy scores of 0, 1, 2, and 3 were associated with accuracy rates of six, five, nine, and 36 percent, respectively (P < 0.01). Overall, numeracy was significantly associated with the accuracy of interpreting quantitative benefits of PSA screening. Alternative methods of communicating risk may facilitate shared decision-making in the use of PSA screening for early detection of prostate cancer.

Does a decision aid improve informed choice in mammography screening? Results from a randomised controlled trial

Background

Decision aids can support informed choice in mammography screening, but for the German mammography screening programme no systematically evaluated decision aid exists to date. We developed a decision aid for women invited to this programme for the first time based on the criteria of the International Patient Decision Aids Standards Collaboration.

Objective

To determine whether a decision aid increases informed choice about mammography screening programme participation.

Methods

A representative sample of 7,400 women aged 50 was drawn from registration offices in Westphalia-Lippe, Germany. Women were randomised to receive usual care (i.e., the standard information brochure sent with the programme’s invitation letter) or the decision aid. Data were collected online at baseline, post-intervention, and 3 months follow-up. The primary outcome was informed choice. Secondary outcomes were the constituents of informed choice (knowledge, attitude, intention/uptake), decisional conflict, decision regret, and decision stage. Outcomes were analysed using latent structural equation models and χ²-tests.

Results

1,206 women participated (response rate of 16.3%). The decision aid increased informed choice. Women in the control group had lower odds to make an informed choice at post-intervention (OR 0.26, 95% CI 0.18-0.37) and at follow-up (OR 0.66, 95% CI 0.46-0.94); informed choices remained constant at 30%. This was also reflected in lower knowledge and more decisional conflict. Post-intervention, the uptake intention was higher in the control group, whereas the uptake rate at follow-up was similar. Women in the control group had a more positive attitude at follow-up than women receiving the decision aid. Decision regret and decision stage were not influenced by the intervention.

Conclusion

This paper describes the first systematic evaluation of a newly developed decision aid for the German mammography screening programme in a randomised controlled trial. Our decision aid proved to be an effective tool to enhance the rate of informed choice and was made accessible to the public.

Trial registration

German Clinical Trials Register DRKS00005176.

On Effective Graphic Communication of Health Inequality: Considerations for Health Policy Researchers

Policy Points: Effective graphs can be a powerful tool in communicating health inequality. The choice of graphs is often based on preferences and familiarity rather than science. According to the literature on graph perception, effective graphs allow human brains to decode visual cues easily. Dot charts are easier to decode than bar charts, and thus they are more effective. Dot charts are a flexible and versatile way to display information about health inequality. Consistent with the health risk communication literature, the captions accompanying health inequality graphs should provide a numerical, explicitly calculated description of health inequality, expressed in absolute and relative terms, from carefully thought-out perspectives.

CONTEXT

Graphs are an essential tool for communicating health inequality, a key health policy concern. The choice of graphs is often driven by personal preferences and familiarity. Our article is aimed at health policy researchers developing health inequality graphs for policy and scientific audiences and seeks to (1) raise awareness of the effective use of graphs in communicating health inequality; (2) advocate for a particular type of graph (ie, dot charts) to depict health inequality; and (3) suggest key considerations for the captions accompanying health inequality graphs.

METHODS

Using composite review methods, we selected the prevailing recommendations for improving graphs in scientific reporting. To find the origins of these recommendations, we reviewed the literature on graph perception and then applied what we learned to the context of health inequality. In addition, drawing from the numeracy literature in health risk communication, we examined numeric and verbal formats to explain health inequality graphs.

FINDINGS

Many disciplines offer commonsense recommendations for visually presenting quantitative data. The literature on graph perception, which defines effective graphs as those allowing the easy decoding of visual cues in human brains, shows that with their more accurate and easier-to-decode visual cues, dot charts are more effective than bar charts. Dot charts can flexibly present a large amount of information in limited space. They also can easily accommodate typical health inequality information to describe a health variable (eg, life expectancy) by an inequality domain (eg, income) with domain groups (eg, poor and rich) in a population (eg, Canada) over time periods (eg, 2010 and 2017). The numeracy literature suggests that a health inequality graph's caption should provide a numerical, explicitly calculated description of health inequality expressed in absolute and relative terms, from carefully thought-out perspectives.

CONCLUSIONS

Given the ubiquity of graphs, the health inequality field should learn from the vibrant multidisciplinary literature how to construct effective graphic communications, especially by considering to use dot charts.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Visual Aids for Improving Patient Decision Making in Severe Symptomatic Carotid Stenosis

BACKGROUND

Because of the large amount of information to process and the limited time of a clinical consult, choosing between carotid endarterectomy (CEA) and carotid angioplasty with stenting (CAS) can be confusing for patients with severe symptomatic internal carotid stenosis (ICA).

GOAL

We aim to develop a visual aid tool to help clinicians and patients in the decision-making process of selecting between CEA and CAS.

MATERIALS AND METHODS

Based on pooled analysis from randomized controlled trials including patients with symptomatic and severe ICA (SSICA), we generated visual plots comparing CEA with CAS for 3 prespecified postprocedural time points: (1) any stroke or death at 4 months, and (2) any stroke or death in the first 30 days and ipsilateral stroke thereafter at 5 years and (3) at 10 years.

RESULTS

A total of 4574 participants (2393 assigned to CAS, and 2361 to CEA) were included in the analyses. For every 100 patients with SSICA, 6 would develop any stroke or death in the CEA group compared with 9 undergoing CAS at 4 months (hazard ratio [HR] 1.53; 95%CI 1.20-1.95). At 5 years, 7 patients in the CEA group would develop any periprocedural stroke or death and ipsilateral stroke thereafter versus 12 undergoing CAS (HR 1.72; 95%CI 1.24-2.39), compared with 10 patients in the CEA and 13 in the CAS groups at 10 years (HR 1.17; 95%CI 0.82-1.66).

CONCLUSION

Visual aids presented in this study could potentially help patients with severe symptomatic internal carotid stenosis to better weigh the risks and benefits of CEA versus CAS as a function of time, allowing for the prioritization of personal preferences, and should be prospectively assessed.

Visualizing risks in cancer communication: A systematic review of computer-supported visual aids

OBJECTIVE

Health websites are becoming important sources for cancer information. Lay users, patients and carers seek support for critical decisions, but they are prone to common biases when quantitative information is presented. Graphical representations of risk data can facilitate comprehension, and interactive visualizations are popular. This review summarizes the evidence on computer-supported graphs that present risk data and their effects on various measures.

METHODS

The systematic literature search was conducted in several databases, including MEDLINE, EMBASE and CINAHL. Only studies with a controlled design were included. Relevant publications were carefully selected and critically appraised by two reviewers.

RESULTS

Thirteen studies were included. Ten studies evaluated static graphs and three dynamic formats. Most decision scenarios were hypothetical. Static graphs could improve accuracy, comprehension, and behavioural intention. But the results were heterogeneous and inconsistent among the studies. Dynamic formats were not superior or even impaired performance compared to static formats.

CONCLUSIONS

Static graphs show promising but inconsistent results, while research on dynamic visualizations is scarce and must be interpreted cautiously due to methodical limitations.

PRACTICE IMPLICATIONS

Well-designed and context-specific static graphs can support web-based cancer risk communication in particular populations. The application of dynamic formats cannot be recommended and needs further research.

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

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

Utilization of Continuous "Spinners" to Communicate Risk

BACKGROUND

As patients become more involved in their medical care, they must consider the specific probabilities of both positive and negative outcomes associated with different treatments. Patients who are low in numeracy may be at a disadvantage when making these decisions. This study examined the use of a "spinner" to present probabilistic information compared to a numerical format and icon array.

DESIGN

Subjects ( n = 151) were asked to imagine they suffered from chronic back pain. Two equally effective medications, each with a different incidence of rare and common side effects, were described. Subjects were randomized to 1 of 3 risk presentation formats: numeric only, numeric with icon arrays, or numeric with spinners, and answered questions regarding their risk knowledge, medication preference, and how much they liked the presentation format.

RESULTS

Compared with the numeric only format, both the spinner and icon array increased risk knowledge and were rated more likeable by subjects. Subjects viewing the spinner format were also more likely to prefer the pill with the lowest side-effect burden.

LIMITATIONS

The relatively small size, convenience sample, and hypothetical scenario were limitations of this study.

CONCLUSIONS

The use of continuous spinners presents a new approach for communicating risk to patients that may aid in their decision making.

Parental optimism about childhood obesity-related disease risks

OBJECTIVES

Most parents believe childhood obesity is a problem for society, but not for their own children. We sought to understand whether parents' risk assessment was skewed by optimism, the tendency to overestimate one's chances of experiencing positive events.

METHODS

We administered a national web-based survey to 502 parents of 5-12-year-old children. Parents reported the chances that (a) their child and (b) 'a typical child in their community' would be overweight or obese, and develop hypertension, heart disease, type 2 diabetes and depression in adulthood. Respondents self-reported demographic and health information, and we obtained demographic and health information about the typical child using zip code-level census and lifestyle data. We used regression models with fixed effects to evaluate whether optimism bias was present in parent predictions of children's future health outcomes.

RESULTS

Parents had 40 times lower adjusted odds (OR=0.025, P<0.001, 99% CI: 0.006, 0.100) of predicting that their child (versus a typical child) would be overweight or obese in adulthood. Of the 20% of parents who predicted their child would be overweight in adulthood, 93% predicted the typical child would also be overweight in adulthood. Controlling for health and demographic characteristics, parents estimated that their children's chances of developing obesity-related comorbidities would be 12-14 percentage points lower those that of a typical child.

CONCLUSIONS

Parent risk assessment is skewed by optimism, among other characteristics. More accurate risk perception could motivate parents to engage in behavior change.

Designing Graphs to Communicate Risks: Understanding How the Choice of Graphical Format Influences Decision Making

Previous research suggests that the choice of graphical format for communicating risk information affects both understanding of the risk magnitude and the likelihood of acting to decrease risk. However, the mechanisms through which these effects work are poorly understood. To explore these mechanisms using a real-world scenario, we examined the relative impact of two graphical displays for depicting the risk of exposure to unexploded ammunition during potential land redevelopment. One display depicted only the foreground information graphically (a bar graph of the number of people harmed), and a second depicted the foreground and background graphically (a stacked bar graph representing both the number harmed and at risk). We presented 296 participants with either the foreground-only or the foreground and background graphical display and measured a broad set of outcome variables, examining (1) the graphical display effect on each of the outcome measures and (2) the pathways by which any display effects work to influence decision making. We found that the foreground-only graphical display increased perceived likelihood and experienced fear, which produced greater worry, which in turn increased risk aversion. In addition, a positive evaluation of the communication materials increased support for policies related to land redevelopment, whether those policies were risk taking or risk mitigating. Finally, the foreground-only graphical display decreased understanding of the risk magnitude, showing that approaches to accomplish one risk communication goal (promoting risk-averse decisions) may do so at the expense of another goal (increasing understanding).

The consent process: Enabling or disabling patients' active participation?

Standards expected by doctors' regulatory bodies in respect of the process of consent to treatment have arguably sought to restructure the nature of the doctor-patient relationship from one of the paternalism to that of shared decision-making. Yet, few studies have explored empirically, from patients' perspectives, the extent to which the process of consent to treatment enables or disables patients' participation in medical decision-making. Our article examines patients' attitudes towards the consent process, exploring how and why these attitudes influence patients' active participation in decision-making and considering possible consequent medico-legal issues. Data were collected longitudinally using semi-structured interviews and field observations involving 35 patients and 19 of their caregivers, in an English hospital between February and November 2014. These indicate that generally patients defer to the doctor in respect of treatment decision-making. Although most patients and their caregivers wanted detailed information and discussion, they did not necessarily expect that this would be provided. Furthermore, patients perceived that signing the consent form was an obligatory routine principally to protect doctors from legal action should something go wrong. Our study suggests that patients' predominantly paternalistic perceptions of the consent process can not only undermine attempts by doctors to involve them in decision-making but, as patients are now considered in law as informed actors, their perceptions of the consent form as not being in their interests could be a self-fulfilling prophecy if signing is undertaken without due consideration to the content.

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

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

Icons for health effects of cigarette smoke: a test of semiotic type

We sought to identify icons to effectively communicate health harms of chemicals in cigarette smoke. Participants were a convenience sample of 701 U.S. adults. A within-subjects online experiment explored the effects of icon semiotic type: symbolic (arbitrary, most abstract), indexical, and iconic (representative, most concrete). Outcomes were perceived representation, affect toward smoking, elaboration, perceived severity, and perceived effectiveness. For not-easy-to-visualize harms of cancer and addiction, symbolic icons received the highest ratings (all p < .001). For easy-to-visualize symptoms of heart attack/stroke, indexical icons received the highest ratings (all p < .001). For easy-to-visualize harm of reproductive organ damage, the iconic image did best (all p < .001). Icon type often had a larger impact among participants with higher health literacy. Symbolic icons may be most effective for health effects not easily visualized. Iconic or indexical icons may be more effective for health effects attributable to specific body parts or symptoms.

Accessibility of standardized information of a national colorectal cancer screening program for low health literate screening invitees: A mixed method study

OBJECTIVE

To explore the accessibility of standardized printed information materials of the national Dutch colorectal cancer screening program among low health literate screening invitees and to assess the effect of the information on their knowledge about colorectal cancer and the screening program.

METHODS

Linguistic tools were used to analyze the text and design characteristics. The accessibility, comprehensibility and relevance of the information materials were explored in interviews and in observations (n=25). The effect of the information on knowledge was assessed in an online survey (n=127).

RESULTS

The materials employed a simple text and design. However, respondents expressed problems with the amount of information, and the difference between screening and diagnostic follow-up. Knowledge significantly increased in 10 out of 16 items after reading the information but remained low for colorectal cancer risk, sensitivity of testing, and the voluntariness of colorectal cancer screening.

CONCLUSION

Despite intelligible linguistic and design characteristics, screening invitees with low health literacy had problems in accessing, comprehending and applying standard information materials on colorectal cancer screening, and lacked essential knowledge for informed decision-making about participation.

PRACTICE IMPLICATIONS

To enable equal access to informed decision-making, information strategies need to be adjusted to the skills of low health literate screening invitees.

Development of a Standardized Approach to Disclosing Amyloid Imaging Research Results in Mild Cognitive Impairment

The increased use of PET amyloid imaging in clinical research has sparked numerous concerns about whether and how to return such research test results to study participants. Chief among these is the question of how best to disclose amyloid imaging research results to individuals who have cognitive symptoms that could impede comprehension of the information conveyed. We systematically developed and evaluated informational materials for use in pre-test counseling and post-test disclosures of amyloid imaging research results in mild cognitive impairment (MCI). Using simulated sessions, persons with MCI and their family care partners (N = 10 dyads) received fictitious but realistic information regarding brain amyloid status, followed by an explanation of how results impact Alzheimer's disease risk. Satisfaction surveys, comprehension assessments, and focus group data were analyzed to evaluate the materials developed. The majority of persons with MCI and their care partners comprehended and were highly satisfied with the information presented. Focus group data reinforced findings of high satisfaction and included 6 recommendations for practice: 1) offer pre-test counseling, 2) use clear graphics, 3) review participants' own brain images during disclosures, 4) offer take-home materials, 5) call participants post-disclosure to address emerging questions, and 6) communicate seamlessly with primary care providers. Further analysis of focus group data revealed that participants understood the limitations of amyloid imaging, but nevertheless viewed the prospect of learning one's amyloid status as valuable and empowering.

Optimal design and patient selection for interventional trials using radiogenomic biomarkers: A REQUITE and Radiogenomics consortium statement

The optimal design and patient selection for interventional trials in radiogenomics seem trivial at first sight. However, radiogenomics do not give binary information like in e.g. targetable mutation biomarkers. Here, the risk to develop severe side effects is continuous, with increasing incidences of side effects with higher doses and/or volumes. In addition, a multi-SNP assay will produce a predicted probability of developing side effects and will require one or more cut-off thresholds for classifying risk into discrete categories. A classical biomarker trial design is therefore not optimal, whereas a risk factor stratification approach is more appropriate. Patient selection is crucial and this should be based on the dose-response relations for a specific endpoint. Alternatives to standard treatment should be available and this should take into account the preferences of patients. This will be discussed in detail.

Development and Validation of the Spanish Numeracy Understanding in Medicine Instrument

BACKGROUND

The Spanish-speaking population in the U.S. is large and growing and is known to have lower health literacy than the English-speaking population. Less is known about the health numeracy of this population due to a lack of health numeracy measures in Spanish.

OBJECTIVE

we aimed to develop and validate a short and easy to use measure of health numeracy for Spanish-speaking adults: the Spanish Numeracy Understanding in Medicine Instrument (Spanish-NUMi).

DESIGN

Items were generated based on qualitative studies in English- and Spanish-speaking adults and translated into Spanish using a group translation and consensus process. Candidate items for the Spanish NUMi were selected from an eight-item validated English Short NUMi. Differential Item Functioning (DIF) was conducted to evaluate equivalence between English and Spanish items. Cronbach's alpha was computed as a measure of reliability and a Pearson's correlation was used to evaluate the association between test scores and the Spanish Test of Functional Health Literacy (S-TOFHLA) and education level.

PARTICIPANTS

Two-hundred and thirty-two Spanish-speaking Chicago residents were included in the study.

KEY RESULTS

The study population was diverse in age, gender, and level of education and 70 % reported Mexico as their country of origin. Two items of the English eight-item Short NUMi demonstrated DIF and were dropped. The resulting six-item test had a Cronbach's alpha of 0.72, a range of difficulty using classical test statistics (percent correct: 0.48 to 0.86), and adequate discrimination (item-total score correlation: 0.34-0.49). Scores were positively correlated with print literacy as measured by the S- TOFHLA (r = 0.67; p < 0.001) and varied as predicted across grade level; mean scores for up to eighth grade, ninth through twelfth grade, and some college experience or more, respectively, were 2.48 (SD ± 1.64), 4.15 (SD ± 1.45), and 4.82 (SD ± 0.37).

CONCLUSIONS

The Spanish NUMi is a reliable and valid measure of important numerical concepts used in communicating health information.

The Association of Graph Literacy With Use of and Skills Using an Online Personal Health Record in Outpatient Veterans

Personal health records (PHRs) are intended to increase patients' access to and ownership over their health care information for self-management purposes. The purpose of this study was to determine the association of graph literacy with adoption of an online PHR and, among adopters with self-reported skills, the frequency of use and intent to return to use the PHR . We conducted a cross-sectional survey of veterans receiving outpatient care. We measured health literacy, numeracy, graph literacy, and Internet and PHR adoption and use. We compared subgroups of veterans using analyses of covariance. We used hierarchical logistic regression models to estimate the effects of the literacy variables on PHR use. A total of 600 veterans (age = 22-94) participated in the survey. After we adjusted for known covariates, we found that adopters of a PHR were more likely to demonstrate higher health and graph literacy than nonadopters. Among PHR adopters, self-reported frequent and skillful users were more likely to have higher graph literacy than lower frequency and less skillful users. Adopters with higher intentions to return to use the PHR were more likely to show lower graph literacy than those less likely to return to use the PHR. Inadequate graph literacy was associated with lower adoption of a PHR and, among users, with lower self-reported frequent use and skills . As PHR use becomes more widespread, stakeholders will need to consider patients' levels of graph literacy when implementing PHRs.

Content analysis of comparative claims in drug advertisements

Purpose

The purpose of this study is to describe the trends and practices of comparative prescription drug advertising by examining the types of comparative claims made in direct-to-consumer (DTC) and direct-to-physician (DTP) print advertisements.

Design/methodology/approach

The authors conducted a content analysis of 54 DTC and DTP print prescription drug advertisements (published between 1997 and 2014) with comparative claims.

Findings

Efficacy-based comparisons appeared in 64 per cent of advertisements, and attribute-based comparisons appeared in 37 per cent of advertisements. Most advertisements made direct (vs indirect) references to competitors (85 per cent), compared the advertised drug to a single (vs multiple) competitor (78 per cent), focused exclusively on one type of comparison claim (i.e. efficacy-, risk- or attribute-based) (70 per cent) and did not contain data-driven visual aids (82 per cent). Some differences between DTC and DTP advertisements emerged. More DTP than DTC advertisements included data-driven visual aids (82 per cent vs 0 per cent, respectively), included numerical data (88 per cent vs 53 per cent) and conveyed statistical significance (52 per cent vs 12 per cent).

Research limitations/implications

The study used a convenience sample rather than a random sample of advertisements; thus, the findings might not be generalizable to all pharmaceutical DTC and DTP advertisements. Examining the tactics that advertisers use to educate and influence consumers and physicians sets the foundation for future studies that examine the effects of their exposure to comparative claims. Suggestions for future research are discussed.

Originality/value

This study is the first to examine and statistically compare the comparative advertising tactics used in both consumer and physician prescription drug advertisements.

Improving risk literacy in surgeons

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

PRACTICE IMPLICATIONS

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

Measuring Graph Literacy without a Test: A Brief Subjective Assessment

BACKGROUND

Visual aids tend to help diverse and vulnerable individuals understand risk communications, as long as these individuals have a basic understanding of graphs (i.e., graph literacy). Tests of objective graph literacy (OGL) can effectively identify individuals with limited skills, highlighting vulnerabilities and facilitating custom-tailored risk communication. However, the administration of these tests can be time-consuming and may evoke negative emotional reactions (e.g., anxiety).

OBJECTIVES

To evaluate a brief and easy-to-use assessment of subjective graph literacy (SGL) (i.e., self-reported ability to process and use graphically presented information) and to estimate the robustness and validity of the SGL scale and compare it with the leading OGL scale in diverse samples from different cultures.

PARTICIPANTS

Demographically diverse residents (n = 470) of the United States, young adults (n = 172) and patients (n = 175) from Spain, and surgeons (n = 175) from 48 countries.

DESIGN

A focus group and 4 studies for instrument development and initial validation (study 1), reliability and convergent and discriminant validity evaluation (study 2), and predictive validity estimation (studies 3 and 4).

MEASURES

Psychometric properties of the scale.

RESULTS

In about 1 minute, the SGL scale provides a reliable, robust, and valid assessment of skills and risk communication preferences and evokes fewer negative emotional reactions than the OGL scale.

CONCLUSIONS

The SGL scale can be suitable for use in clinical research and may be useful as a communication aid in clinical practice. Theoretical mechanisms involved in SGL, emerging applications, limitations, and open questions are discussed.

Is patients' numeracy related to physical and mental health?

OBJECTIVE

There is compelling evidence showing that health literacy influences health outcomes. However, there is a dearth of research investigating this issue in the vast literature on numeracy-the ability to accurately interpret numerical information about risk, a skill that is only moderately correlated with health literacy. In a cross-sectional study, we investigated whether objective and subjective numeracy is related to objective and subjective health outcomes. Objective (subjective) numeracy is actual (self-reported) numerical competence. Objective outcomes include prevalence of comorbidity and prescribed medications. Subjective outcomes include perceptions of physical and mental health.

METHODS

A convenience sample of 502 male individuals receiving outpatient care at a Veterans Affairs Medical Center reported their demographics and answered a survey measuring objective and subjective numeracy, trust in physicians, satisfaction with role in medical decision making, perceptions of physical and mental health, and risky habits. We computed patients' body mass index (BMI) and their age-adjusted Charlson index-an extensively studied comorbidity index for predicting mortality in clinical research. We retrieved number of prescribed medications from medical records.

RESULTS

Compared with patients who had high objective numeracy, patients with low objective numeracy showed higher prevalence of comorbidities and took more prescribed medications. Compared with patients who had high subjective numeracy, patients with low subjective numeracy had more negative perceptions of their physical and mental health. These conclusions held after controlling for the effect of demographics, risky habits, BMI, trust in physicians, and satisfaction with role in decision making, suggesting that numeracy has a unique, significant contribution to health outcomes beyond the effect of these factors.

CONCLUSIONS

Our research documents for the first time that self-reported numeracy is related to perceptions of health, whereas objective numeracy is related to actual health, laying the groundwork for future research on the effect of numeracy on health outcomes.

Nurses' Numeracy and Graphical Literacy: Informing Studies of Clinical Decision Support Interfaces

We present findings of a comparative study of numeracy and graph literacy in a representative group of 60 practicing nurses. This article focuses on a fundamental concern related to the effectiveness of numeric information displayed in various features in the electronic health record during clinical workflow. Our findings suggest the need to consider numeracy and graph literacy when presenting numerical information as well as the potential for tailoring numeric display types to an individual's cognitive strengths.

Improving Bayesian Reasoning: The Effects of Phrasing, Visualization, and Spatial Ability

Decades of research have repeatedly shown that people perform poorly at estimating and understanding conditional probabilities that are inherent in Bayesian reasoning problems. Yet in the medical domain, both physicians and patients make daily, life-critical judgments based on conditional probability. Although there have been a number of attempts to develop more effective ways to facilitate Bayesian reasoning, reports of these findings tend to be inconsistent and sometimes even contradictory. For instance, the reported accuracies for individuals being able to correctly estimate conditional probability range from 6% to 62%. In this work, we show that problem representation can significantly affect accuracies. By controlling the amount of information presented to the user, we demonstrate how text and visualization designs can increase overall accuracies to as high as 77%. Additionally, we found that for users with high spatial ability, our designs can further improve their accuracies to as high as 100%. By and large, our findings provide explanations for the inconsistent reports on accuracy in Bayesian reasoning tasks and show a significant improvement over existing methods. We believe that these findings can have immediate impact on risk communication in health-related fields.

Effect of format on comprehension of adherence data in chronic disease: A cross-sectional study in HIV

OBJECTIVE

To determine which formats communicate medication adherence effectively to patients.

METHODS

HIV-infected adults on antiretrovirals viewed examples of refill data in 5 formats: (1) percentage of doses, (2) number of days late to refill ("days late"), (3) calendar of days with/without medications, (4) pie chart of days with/without medications, and (5) letter grade. Five scenarios (>95%, 90-95%, <90%, <80% and <70% adherence) were presented in each format. Participants rated scenarios on adherence improvement needed. "Good understanding" was ≥ 4 of 5 scenarios correct. We calculated odds ratios for "good understanding" using logistic regression with percentage as the referent format.

RESULTS

124 participants were median age 48.5 years, 65% Black, 71% male. Understanding of all formats differed by education (all interaction p values<0.02). For ≤ 12 years education, odds ratios (OR) of understanding (95% CI) compared to percentage were: days late 3.3 (2.3-4.7), calendar 3.1 (2.2-4.3) pie chart 2.0 (1.4-2.7), and letter grade 1.8 (1.3-2.5). For >12 years education, ORs were: days late 1.3 (0.9-2.0), calendar 2.4 (1.5-3.8), pie chart 2.9 (1.8-4.6), and letter grade 1.7 (1.1-2.6). Calendar plot was most preferred.

CONCLUSIONS

Adherence percentage was the least understood format regardless of education.

PRACTICE IMPLICATIONS

Calendars should be used to convey adherence information.

Graphical Aids to the Estimation and Discrimination of Uncertain Numerical Data

This research investigates the performance of graphical dot arrays designed to make discrimination of relative numerosity as effortless as possible at the same time as making absolute (quantitative) numerosity estimation as effortful as possible. Comparing regular, random, and hybrid (randomized regular) configurations of dots, the results indicate that both random and hybrid configurations reduce absolute numerosity estimation precision, when compared with regular dots arrays. However, discrimination of relative numerosity is significantly more accurate for hybrid dot arrays than for random dot arrays. Similarly, human subjects report significantly lower levels of subjective confidence in judgments when using hybrid dot configurations as compared with regular configurations; and significantly higher levels of subjective confidence as compared with random configurations. These results indicate that data graphics based on the hybrid, randomized-regular configurations of dots are well-suited to applications that require decisions to be based on numerical data in which the absolute quantities are less certain than the relative values. Examples of such applications include decision-making based on the outputs of empirically-based mathematical models, such as health-related policy decisions using data from predictive epidemiological models.

Public preferences for communicating personal genomic risk information: a focus group study

Background

Personalized genomic risk information has the potential to motivate behaviour change and promote population health, but the success of this will depend upon effective risk communication strategies.

Objective

To determine preferences for different graphical and written risk communication formats, and the delivery of genomic risk information including the mode of communication and the role of health professionals.

Design

Focus groups, transcribed and analysed thematically.

Participants

Thirty‐four participants from the public.

Methods

Participants were provided with, and invited to discuss, a hypothetical scenario giving an individual's personalized genomic risk of melanoma displayed in several graphical formats.

Results

Participants preferred risk formats that were familiar and easy to understand, such as a ‘double pie chart’ and ‘100 person diagram’ (pictograph). The 100 person diagram was considered persuasive because it humanized and personalized the risk information. People described the pie chart format as resembling bank data and food (such as cake and pizza). Participants thought that email, web‐based platforms and postal mail were viable options for communicating genomic risk information. However, they felt that it was important that a health professional (either a genetic counsellor or ‘informed’ general practitioner) be available for discussion at the time of receiving the risk information, to minimize potential negative emotional responses and misunderstanding. Face‐to‐face or telephone delivery was preferred for delivery of high‐risk results.

Conclusions

These public preferences for communication strategies for genomic risk information will help to guide translation of genome‐based knowledge into improved population health.

Is the “Heart Age” Concept Helpful or Harmful Compared to Absolute Cardiovascular Disease Risk? An Experimental Study

Background. Cardiovascular disease (CVD) prevention guidelines are generally based on the absolute risk of a CVD event, but there is increasing interest in using ‘heart age’ to motivate lifestyle change when absolute risk is low. Previous studies have not compared heart age to 5-year absolute risk, or investigated the impact of younger heart age, graphical format, and numeracy. Objective. Compare heart age versus 5-year absolute risk on psychological and behavioral outcomes. Design. 2 (heart age, absolute risk) × 3 (text only, bar graph, line graph) experiment. Setting. Online. Participants. 570 Australians aged 45–64 years, not taking CVD-related medication. Intervention. CVD risk assessment. Measurements. Intention to change lifestyle, recall, risk perception, emotional response, perceived credibility, and lifestyle behaviors after 2 weeks. Results. Most participants had lifestyle risk factors (95%) but low 5-year absolute risk (94%). Heart age did not improve lifestyle intentions and behaviors compared to absolute risk, was more often interpreted as a higher-risk category by low-risk participants (47% vs 23%), and decreased perceived credibility and positive emotional response. Overall, correct recall dropped from 65% to 24% after 2 weeks, with heart age recalled better than absolute risk at 2 weeks (32% vs 16%). These results were found across younger and older heart age results, graphical format, and numeracy. Limitations. Communicating CVD risk in a consultation rather than online may produce different results. Conclusions. There is no evidence that heart age motivates lifestyle change more than 5-year absolute risk in individuals with low CVD risk. Five-year absolute risk may be a better way to explain CVD risk, because it is more credible, does not inflate risk perception, and is consistent with clinical guidelines that base lifestyle and medication recommendations on absolute risk.

Barriers in using cardiometabolic risk information among consumers with low health literacy

OBJECTIVES

To identify the barriers from the perspective of consumers with low health literacy in using risk information as provided in cardiometabolic risk assessments.

DESIGN

A qualitative thematic approach using cognitive interviews was employed.

METHODS

We performed interviews with 23 people with low health literacy/health numeracy, who were recruited through (1) several organisations and snowball sampling and (2) an online access panel. Participants completed the risk test of the Dutch national cardiometabolic risk assessment and viewed the personalized information about their risk. They were asked to answer probing questions about different parts of the information. The qualitative data were analysed by identifying main themes related to barriers in using the information, using a descriptive thematic approach.

RESULTS

The four main themes identified were as follows: (1) People did not fully accept the risk message, partly because numerical information had ambiguous meaning; (2) people lacked an adequate framework for understanding their risk; (3) the purpose and setting of the risk assessment was unclear; and (4) current information tells nothing new: A need for more specific risk information.

CONCLUSIONS

The main barriers were that the current presentation seemed to provoke undervaluation of the risk number and that texts throughout the test, for example about cardiometabolic diseases, did not match people's existing knowledge, failing to provide an adequate framework for understanding cardiometabolic risk. Our findings have implications for the design of disease risk information, for example that alternative forms of communication should be explored that provide more intuitive meaning of the risk in terms of good versus bad.

STATEMENT OF CONTRIBUTION

What is already known on this subject? Online disease risk assessments have become widely available internationally. People with low SES and health literacy tend to participate less in health screening. Risk information is difficult to understand, yet little research has been carried out among people with low health literacy. What does this study add? People with low health literacy do not optimally use risk information in an online cardiometabolic risk assessment. The texts provided in the cardiometabolic risk assessment do not suit to their existing knowledge. The typical risk communication (numbers, bar graph, verbal label) seems to provoke undervaluation of risk.

Visual aids improve diagnostic inferences and metacognitive judgment calibration

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

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

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

Understanding the Harms and Benefits of Cancer Screening

Objective. Decisions about cancer screenings often involve the consideration of complex and counterintuitive evidence. We investigated psychological factors that promote the comprehension of benefits and harms associated with common cancer screenings and their influence on shared decision making. Methods. In experiment 1, 256 men received information about PSA-based prostate cancer screening. In experiment 2, 355 women received information about mammography-based breast cancer screening. In both studies, information about potential screening outcomes was provided in 1 of 3 formats: text, a fact box, or a visual aid (e.g., mortality with and without screening and rate of overdiagnosis). We modeled the interplay of comprehension, perceived risks and benefits, intention to participate in screening, and desire for shared decision making. Results. Generally, visual aids were the most effective format, increasing comprehension by up to 18%. Improved comprehension was associated with 1) superior decision making (e.g., fewer intentions to participate in screening when it offered no benefit) and 2) more desire to share in decision making. However, comprehension of the evidence had a limited effect on experienced emotions, risk perceptions, and decision making among those participants who felt that the consequences of cancer were extremely severe. Conclusions. Even when information is counterintuitive and requires the integration of complex harms and benefits, user-friendly risk communications can facilitate comprehension, improve high-stakes decisions, and promote shared decision making. However, previous beliefs about the effectiveness of screening or strong fears about specific cancers may interfere with comprehension and informed decision making.

Low health literacy predicts decline in physical function among older adults: findings from the LitCog cohort study

BACKGROUND

Limited health literacy is associated with worse physical function in cross-sectional studies. We aimed to determine if health literacy is a risk factor for decline in physical function among older adults.

METHODS

A longitudinal cohort of 529 community-dwelling American adults aged 55-74 years were recruited from an academic general internal medicine clinic and federally qualified health centres in 2008-2011. Health literacy (Newest Vital Sign), age, gender, race, education, chronic conditions, body mass index, alcohol consumption, smoking status and exercise frequency were included in multivariable analyses. The 10-item PROMIS (Patient-Reported Outcomes Measurement Information System) physical function scale was assessed at baseline and follow-up (mean=3.2 years, SD=0.39).

RESULTS

Nearly half of the sample (48.2%) had either marginal (25.5%) or low health literacy (22.7%). Average physical function at baseline was 83.2 (SD=16.6) of 100, and health literacy was associated with poorer baseline physical function in multivariable analysis (p=0.004). At follow-up, physical function declined to 81.9 (SD=17.3; p=0.006) and 20.5% experienced a meaningful decline (>0.5 SD of baseline score). In multivariable analyses, participants with marginal (OR 2.62; 95%CI 1.38 to 4.95; p=0.003) and low (OR 2.57; 95%CI 1.22 to 5.44; p=0.013) health literacy were more likely to experience meaningful decline in physical function than the adequate health literacy group. Entering cognitive abilities to these models did not substantially attenuate effect sizes. Health literacy attenuated the relationship between black race and decline in physical function by 32.6%.

CONCLUSIONS

Lower health literacy increases the risk of exhibiting faster physical decline over time among older adults. Strategies that reduce literacy disparities should be designed and evaluated.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

InformedTogether: Usability Evaluation of a Web-Based Decision Aid to Facilitate Shared Advance Care Planning for Severe Chronic Obstructive Pulmonary Disease

Background

Advance care planning may help patients receive treatments that better align with their goals for care. We developed a Web-based decision aid called InformedTogether to facilitate shared advance care planning between chronic obstructive pulmonary disease (COPD) patients and their doctors.

Objective

Our objective was to assess the usability of the InformedTogether decision aid, including whether users could interact with the decision aid to engage in tasks required for shared decision making, whether users found the decision aid acceptable, and implications for redesign.

Methods

We conducted an observational study with 15 patients and 8 doctors at two ethnically and socioeconomically diverse outpatient clinics. Data included quantitative and qualitative observations of patients and doctors using the decision aid on tablet or laptop computers and data from semistructured interviews. Patients were shown the decision aid by a researcher acting as the doctor. Pulmonary doctors were observed using the decision aid independently and asked to think aloud (ie, verbalize their thoughts). A thematic analysis was implemented to explore key issues related to decision aid usability.

Results

Although patients and doctors found InformedTogether acceptable and would recommend that doctors use the decision aid with COPD patients, many patients had difficulty understanding the icon arrays that were used to communicate estimated prognoses and could not articulate the definitions of the two treatment choices—Full Code and Do Not Resuscitate (DNR). Minor usability problems regarding content, links, layout, and consistency were also identified and corresponding recommendations were outlined. In particular, participants suggested including more information about potential changes in quality of life resulting from the alternative advance directives. Some doctor participants thought the decision aid was too long and some thought it may cause nervousness among patients due to the topic area.

Conclusions

A decision aid for shared advance care planning for severe COPD was found acceptable to most COPD patients and their doctors. However, many patient participants did not demonstrate understanding of the treatment options or prognostic estimates. Many participants endorsed the use of the decision aid between doctors and their patients with COPD, although they desired more information about quality of life. The design must optimize comprehensibility, including revising the presentation of statistical information in the icon array, and feasibility of integration into clinical workflow, including shortening the decision aid.

Message Formats, Numeracy, Risk Perceptions of Alcohol-Attributable Cancer, and Intentions for Binge Drinking Among College Students

We conducted an experiment to examine whether risk perceptions of alcohol-attributable cancer influence college students' binge-drinking intention and to explore how message formats (text, table, and graph) and numeracy influence risk perceptions of alcohol-attributable cancer. We found that a majority of participants (87%) perceive some risks of alcohol-attributable cancer. Risk messages in tabular and graphic formats are more effective in elevating risk perceptions, but there is no significant difference between these two formats. Numeracy and its interaction with message formats, however, do not predict risk perceptions. We recommend risk messages should be delivered using tabular or graphic formats to enhance risk perceptions. We also advocate the less-is-more principle in presenting risk information.

Development of a tiered and binned genetic counseling model for informed consent in the era of multiplex testing for cancer susceptibility

PURPOSE

Multiplex genetic testing, including both moderate- and high-penetrance genes for cancer susceptibility, is associated with greater uncertainty than traditional testing, presenting challenges to informed consent and genetic counseling. We sought to develop a new model for informed consent and genetic counseling for four ongoing studies.

METHODS

Drawing from professional guidelines, literature, conceptual frameworks, and clinical experience, a multidisciplinary group developed a tiered-binned genetic counseling approach proposed to facilitate informed consent and improve outcomes of cancer susceptibility multiplex testing.

RESULTS

In this model, tier 1 "indispensable" information is presented to all patients. More specific tier 2 information is provided to support variable informational needs among diverse patient populations. Clinically relevant information is "binned" into groups to minimize information overload, support informed decision making, and facilitate adaptive responses to testing. Seven essential elements of informed consent are provided to address the unique limitations, risks, and uncertainties of multiplex testing.

CONCLUSION

A tiered-binned model for informed consent and genetic counseling has the potential to address the challenges of multiplex testing for cancer susceptibility and to support informed decision making and adaptive responses to testing. Future prospective studies including patient-reported outcomes are needed to inform how to best incorporate multiplex testing for cancer susceptibility into clinical practice.Genet Med 17 6, 485-492.

Numeracy and literacy independently predict patients' ability to identify out-of-range test results

BACKGROUND

Increasing numbers of patients have direct access to laboratory test results outside of clinical consultations. This offers increased opportunities for both self-management of chronic conditions and advance preparation for clinic visits if patients are able to identify test results that are outside the reference ranges.

OBJECTIVE

Our objective was to assess whether adults can identify laboratory blood test values outside reference ranges when presented in a format similar to some current patient portals implemented within electronic health record (EHR) systems.

METHODS

In an Internet-administered survey, adults aged 40-70 years, approximately half with diabetes, were asked to imagine that they had type 2 diabetes. They were shown laboratory test results displayed in a standard tabular format. We randomized hemoglobin A1c values to be slightly (7.1%) or moderately (8.4%) outside the reference range and randomized other test results to be within or outside their reference ranges (ie, multiple deviations). We assessed (1) whether respondents identified the hemoglobin A1c level as outside the reference range, (2) how respondents rated glycemic control, and (3) whether they would call their doctor. We also measured numeracy and health literacy.

RESULTS

Among the 1817 adult participants, viewing test results with multiple deviations increased the probability of identifying hemoglobin A1c values as outside the reference range (participants with diabetes: OR 1.47, 95% CI 1.12-1.92, P=.005; participants without diabetes: OR 1.50, 95% CI 1.13-2.00, P=.005). Both numeracy and health literacy were significant predictors of correctly identifying out-of-range values. For participants with diabetes, numeracy OR 1.32 per unit on a 1-6 scale (95% CI 1.15-1.51, P<.001) and literacy OR 1.59 per unit of a 1-5 scale (95% CI 1.35-1.87, P<.001); for participants without diabetes, numeracy OR 1.36 per unit (95% CI 1.17-1.58, P<.001) and literacy OR 1.33 per unit (95% CI 1.12-1.58, P=.001). Predicted probabilities suggested 77% of higher numeracy and health literacy participants, but only 38% of lower numeracy and literacy participants, could correctly identify the hemoglobin A1c levels as outside the reference range. Correct identification reduced perceived blood glucose control (mean difference 1.68-1.71 points on a 0-10 scale, P<.001). For participants with diabetes, increased health literacy reduced the likelihood of calling one's doctor when hemoglobin A1c=7.1% (OR 0.66 per unit, 95% CI 0.52-0.82, P<.001) and increased numeracy increased intention to call when hemoglobin A1c=8.4% (OR 1.36 per unit, 95% CI 1.10-1.69, P=.005).

CONCLUSIONS

Limited health literacy and numeracy skills are significant barriers to basic use of laboratory test result data as currently presented in some EHR portals. Regarding contacting their doctor, less numerate and literate participants with diabetes appear insensitive to the hemoglobin A1c level shown, whereas highly numerate and literate participants with diabetes appear very sensitive. Alternate approaches appear necessary to make test results more meaningful.