Helping Doctors and Patients Make Sense of Health Statistics

A Simple Tool for Communicating the Benefits and Harms of Health Interventions: A Guide for Creating a Fact Box

One of the major hurdles to promoting informed decision making in health is the continued use of poor risk presentation formats. This article offers a guide to develop a Fact Box, a simple decision tool to present data about the benefits and harms of treatments that has been demonstrated to improve understanding of health risks, an important part of risk literacy. The article offers guidance about how to determine the evidence basis for a health topic, select outcomes to report, extract and present numbers or outcomes, and design the layout. The guide also addresses potential challenges for summarizing evidence and provides alternatives for addressing issues related to missing, insufficient, imprecise, or conflicting evidence and for dealing with issues related to statistical and clinical significance. The guide concludes with details on how to document the development of the Fact Box for the purpose of transparency and reproducibility. Fact Boxes are an efficient tool to promote risk literacy and should be available in every physician's office.

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.

Lower parental numeracy is associated with children being under- and overweight

BACKGROUND

In adults, lower numeracy is associated with poorer nutrition label comprehension and higher BMI. It remains unclear whether parental numeracy also impacts children's body weight.

PURPOSE

We examined the relationship between parental numeracy and children's BMI z-scores and analyzed whether weight-related numerical information processing skills-specifically, portion-size estimation skills, comprehension of nutrition labels, and comprehension of growth charts-mediated that relationship.

DESIGN AND METHODS

Numeracy, portion-size estimation skills, comprehension of nutrition labels, and comprehension of growth charts were assessed in face-to-face interviews with 320 parents of children aged 6-12 years in Germany. Parent and child body weight were measured; parents reported both their own height and that of their children.

RESULTS

Lower parental numeracy was significantly associated with having a child who was either underweight (β = 0.126, P = 0.048) or overweight (β = -0.299, P < 0.001). Lower parental numeracy was also associated with poorer portion-size estimation skills (r = -0.08, P = 0.023) and inferior comprehension of growth charts (r = 0.33, P < 0.001) and nutrition labels (r = 0.26, P < 0.001). However, these weight-related numerical information processing skills did not mediate the association between parental numeracy and children's BMI.

CONCLUSION

This study is the first to find lower parental numeracy to be a risk factor for children being either over- or underweight. However, portion-size estimation skills, comprehension of nutrition labels, and comprehension of growth charts did not mediate the association between parental numeracy and children's BMI. The present findings thus winnow down the set of mechanisms potentially underlying this association. Parental numeracy is an as yet largely overlooked factor that can be targeted when developing interventions to prevent and treat malnutrition and to achieve and maintain a healthy body weight in children.

From Bill Shankly to the Huffington Post: How to Increase Critical Thinking in Experimental Psychology Course?

Although critical thinking and source checking are basic prerequisites to become a psychologist, or a scientist, it is usually difficult to have students interested in experimental methods courses. Most first year students are tempted not to attend these courses. Such behaviors are reinforced by arguments that "everybody is different" and "people are not numbers." Consequently, students have difficulties to develop source and evidence checking skills, and may be more prone to believe in any supposed expert. This paper presents two ways to involve students during lectures and seminars. The first method consists in presenting, during the initial lecture of the year, a fake scientific concept which students will believe as true. This phenomenon is called the "Bill Shankly syndrome" and it only exists if someone believes that the information is given by a serious lecturer, presenting oneself as a world-class researcher. The second method consists in training students to become reviewers using evidence checking of a mainstream media article which promises scientifically proven ways to be happy. The use of these methods may stimulate students' interest in research methods and its practical applications from week one.

Planning clinically relevant biomarker validation studies using the "number needed to treat" concept

Purpose

Despite an explosion of translational research to exploit biomarkers in diagnosis, prediction and prognosis, the impact of biomarkers on clinical practice has been limited. The elusiveness of clinical utility may partly originate when validation studies are planned, from a failure to articulate precisely how the biomarker, if successful, will improve clinical decision-making for patients. Clarifying what performance would suffice if the test is to improve medical care makes it possible to design meaningful validation studies. But methods for tackling this part of validation study design are undeveloped, because it demands uncomfortable judgments about the relative values of good and bad outcomes resulting from a medical decision.

Methods

An unconventional use of “number needed to treat” (NNT) can structure communication for the trial design team, to elicit purely value-based outcome tradeoffs, conveyed as the endpoints of an NNT “discomfort range”. The study biostatistician can convert the endpoints into desired predictive values, providing criteria for designing a prospective validation study. Next, a novel “contra-Bayes” theorem converts those predictive values into target sensitivity and specificity criteria, to guide design of a retrospective validation study. Several examples demonstrate the approach.

Conclusion

In practice, NNT-guided dialogues have contributed to validation study planning by tying it closely to specific patient-oriented translational goals. The ultimate payoff comes when the report of the completed study includes motivation in the form of a biomarker test framework directly reflecting the clinical decision challenge to be solved. Then readers will understand better what the biomarker test has to offer patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-016-0862-4) contains supplementary material, which is available to authorized users.

Patients' perceptions of mortality risk for localized prostate cancer vary markedly depending on their treatment strategy

Treatment choice for localized prostate cancer (PCa) is a controversial issue, and mortality risk is probably the most decisive factor in this regard. The study aimed to compare prostate-cancer-specific mortality risk estimates for different treatment options assigned by patients managed with active surveillance (AS), radical prostatectomy (RP) and patients who had discontinued AS (DAS). Patients initially managed with AS or RP (N = 370) were matched according to length of therapy. All patients completed mailed questionnaires assessing their mortality risk estimates (in %) and prostate-cancer-specific anxiety. Differences in risk estimates among the three treatment groups were analyzed using ANOVA, relationships of clinical and psychosocial variables with risk estimates using standard multiple regression. In all treatment groups, the prostate- cancer-specific mortality risk was overestimated. This applied whether it was the patient's own treatment or the alternative treatment option. RP patients assigned a mortality risk to AS that was almost three times higher than that assigned to RP (50.9 ± 25.0 vs. 17.8 ± 19.7, d = 1.48; p < 0.001). Anxiety was significantly associated with risk estimates for AS (p = 0.008) and RP (p = 0.001). Compared with clinical data that suggest that the prostate-cancer-specific mortality risk for AS is low and does not significantly differ from that for RP, patients strongly overestimated the mortality risk. This was most markedly so in RP patients, who drastically overestimated the benefits of RP compared to the risk of AS. This overestimation could increase overtreatment and should therefore be corrected by better patient education.

Patient engagement and shared decision-making: What do they look like in neurology practice?

Neurology is inherently patient-centered given that clinical uncertainty is common, forcing physicians, patients, and families to partner on treatment approach. An increasing emphasis on patient-centered care, patient engagement, and shared decision-making (SDM) in health care provides neurologists with an opportunity to reassess current clinical approaches to decision-making. Such assessment is not simply theoretical but has clear practice implications, with patients indicating a desire for SDM and calls for reimbursement to be tied to demonstration of SDM in practice. We present a framework for how neurologists enhance patient-centered practice by (1) eliciting patients' values and goals, (2) targeting discussion of clinical options to those values and goals, and (3) partnering with patients to make individualized decisions. We also highlight resources that facilitate SDM and examples of SDM in neurology clinical practice.

Buyer beware: health choices information broadcast to the public

Purpose

– This paper is based on the author’s 2015 Northwest Patient Safety Conference presentation, consistent with a conference theme of improving doctor-patient communication. The paper aims to discuss these issues.

Design/methodology/approach

– Ongoing systematic accumulation and critical review of research literature regarding design of effective public information websites, conducted from 2008-2015 while the author was supervising the prototyping, refinement and evaluation of healthcare-associated infections public information websites.

Findings

– In 2005, the US Centers for Medicare and Medicaid Services launched its Hospital Compare website, announced as an enormous step forward by providing objective information to inform consumer choices. Subsequently, many other websites and programs emerged to report quality-of-care ratings of hospitals and doctors, and provide other advice intended to help the public inform their choices. When objectively evaluated to a scientific publication-level standard, websites like Hospital Compare show relatively low usage and disappointing impact; individual providers rank so differently across ratings websites that it is difficult to see how trustworthy conclusions could be drawn; and much of the advice offered through popular media is not supported by believable evidence. Further, research shows healthcare professionals and members of the lay public view concepts of evidence and evidence-based decisions quite differently. Badly informed misguided decisions can have negative consequences for providers, patients and public trust.

Originality/value

– Populism and celebrity seem to have trumped science during recent growth of public information resources for health choices. This paper summarizes serious flaws underlying resulting information products, indicating necessary changes to better serve a legitimate need.

Attitudes towards personal genomics among older Swiss adults: An exploratory study

OBJECTIVES

To explore attitudes of Swiss older adults towards personal genomics (PG).

METHODS

Using an anonymized voluntary paper-and-pencil survey, data were collected from 151 men and women aged 60-89 years attending the Seniorenuniversität Zurich, Switzerland (Seniors' University). Analyses were conducted using descriptive and inferential statistics.

RESULTS

One third of the respondents were aware of PG, and more than half indicated interest in undergoing PG testing. The primary motivation provided was respondents' interest in finding out about their own disease risk, followed by willingness to contribute to scientific research. Forty-four percent were not interested in undergoing testing because results might be worrisome, or due to concerns about the validity of the results. Only a minority of respondents mentioned privacy-related concerns. Further, 66% were interested in undergoing clinic-based PG motivated by the opportunity to contribute to scientific research (78%) and 75% of all study participants indicated strong preferences to donate genomic data to public research institutions.

CONCLUSION

This study indicates a relatively positive overall attitude towards personal genomic testing among older Swiss adults, a group not typically represented in surveys about personal genomics. Genomic data of older adults can be highly relevant to late life health and maintenance of quality of life. In addition they can be an invaluable source for better understanding of longevity, health and disease. Understanding the attitudes of this population towards genomic analyses, although important, remains under-examined.

Presentation of Benefits and Harms in US Cancer Screening and Prevention Guidelines: Systematic Review

BACKGROUND

Cancer prevention and screening guidelines are ideally suited to the task of providing high-quality benefit-harm information that informs clinical practice. We systematically examined how US guidelines present benefits and harms for recommended cancer prevention and screening interventions.

METHODS

We included cancer screening and prevention recommendations from: 1) the United States Preventive Services Task Force, 2) the American Cancer Society, 3) the American College of Physicians, 4) the National Comprehensive Cancer Network, and 5) other US guidelines within the National Guidelines Clearinghouse. Searches took place November 20, 2013, and January 1, 2014, and updates were reviewed through July 1, 2015. Two coders used an abstraction form to code information about benefits and harms presented anywhere within a guideline document, including appendices. The primary outcome was each recommendation's benefit-harm "comparability" rating, based on how benefits and harms were presented. Recommendations presenting absolute effects for both benefits and harms received a "comparable" rating. Other recommendations received an incomplete rating or an asymmetric rating based on prespecified criteria.

RESULTS

Fifty-five recommendations for using interventions to prevent or detect breast, prostate, colon, cervical, and lung cancer were identified among 32 guidelines. Thirty point nine percent (n = 17) received a comparable rating, 14.5% (n = 8) received an incomplete rating, and 54.5% (n = 30) received an asymmetric rating.

CONCLUSIONS

Sixty-nine percent of cancer prevention and screening recommendation statements either did not quantify benefits and harms or presented them in an asymmetric manner. Improved presentation of benefits and harms in guidelines would better ensure that clinicians and patients have access to the information required for making informed decisions.

How best to obtain consent to thrombolysis: Individualized decision-making

OBJECTIVE

To investigate the factors that influence the preferences of patients and their proxies concerning thrombolytic therapy and to determine how best to convey information.

METHODS

A total of 613 participants were randomly assigned to a positively or negatively framed group. Each participant completed a series of surveys. We applied latent class analysis (LCA) to explore participants' patterns of choices of thrombolysis and to classify the participants into different subgroups. Then we performed regression analyses to investigate predictors of classification of the participants into each subgroup and to establish a thrombolytic decision-making model.

RESULTS

LCA indicated an optimal 3-subgroup model comprising intermediate, favorable to thrombolysis, and aversion to thrombolysis subgroups. Multiple regression analysis revealed that 10 factors predicted assignment to the intermediate subgroup and 4 factors predicted assignment to the aversion to thrombolysis subgroup compared with the favorable to thrombolysis subgroup. The χ(2) tests indicated that the information presentation format and the context of thrombolysis influenced participants' choices of thrombolysis and revealed a framing effect in different subgroups.

CONCLUSIONS

The preference for thrombolysis was influenced by the positive vs negative framing scenarios, the format of item presentation, the context of thrombolysis, and individual characteristics. Inconsistent results may be due to participant heterogeneity and the evaluation of limited factors in previous studies. Based on a decision model of thrombolysis, physicians should consider the effects of positive vs negative framing and should seek a neutral tone when presenting the facts, providing an important reference point for health persuasion in other clinical domains.

[Experience of the Mexican National Health System in the development of clinical practice guidelines]

BACKGROUND

Clinical practice guidelines are tools that have been able to streamline decisions made in health issues and to decrease the gap between clinical action and scientific evidence.

OBJECTIVE

The objective of the study is to share the experience in the development and to update the guidelines by the National Health System of Mexico.

MATERIAL AND METHODS

The methodology in the development of the guidelines consists of 5 phases: prioritisation, establishment of work groups, development by adoption of international guidelines of de novo, validation and integration in the Master catalogue of clinical practice guidelines for its dissemination.

RESULTS

The Master catalogue of clinical practice guidelines contains 664 guidelines, distributed in 42% Internal Medicine, 22% Surgery, 24% Pediatrics and 12% Gynecology. From the total of guidelines coverage is granted at an 85% of the Universal catalogue of health services, an 84% of the Catastrophic expenses protection fund and a 61% of the XXI Century Medical Insurance of the National Commission of Social Protection in Health.

DISCUSSION

The result is the sum of a great effort of coordination and cooperation between the institutions of the National Health System, political wills and a commitment of 3,477 health professionals that participate in guidelines' development and update.

CONCLUSION

Master catalogue guidelines' integration, diffusion and implantation improve quality of attention and security of the users of the National Health System.

What are judgment skills in health literacy? A psycho-cognitive perspective of judgment and decision-making research

OBJECTIVE

The aim of this review is to summarize current research relating to psychological processes involved in judgment and decision-making (JDM) and identify which processes can be incorporated and used in the construct of health literacy (HL) in order to enrich its conceptualization and to provide more information about people's preferences.

METHODS

The literature review was aimed at identifying comprehensive research in the field; therefore appropriate databases were searched for English language articles dated from 1998 to 2015.

RESULTS

Several psychological processes have been found to be constituents of JDM and potentially incorporated in the definition of HL: cognition, self-regulation, emotion, reasoning-thinking, and social perception.

CONCLUSION

HL research can benefit from this JDM literature overview, first, by elaborating on the idea that judgment is multidimensional and constituted by several specific processes, and second, by using the results to implement the definition of "judgment skills". Moreover, this review can favor the development of new instruments that can measure HL.

PRACTICAL IMPLICATIONS

Future researchers in HL should work together with researchers in psychological sciences not only to investigate the processes behind JDM in-depth but also to create effective opportunities to improve HL in all patients, to promote good decisions, and orient patients' preferences in all health contexts.

Literature review of visual representation of the results of benefit-risk assessments of medicinal products

BACKGROUND

The PROTECT Benefit-Risk group is dedicated to research in methods for continuous benefit-risk monitoring of medicines, including the presentation of the results, with a particular emphasis on graphical methods.

METHODS

A comprehensive review was performed to identify visuals used for medical risk and benefit-risk communication. The identified visual displays were grouped into visual types, and each visual type was appraised based on five criteria: intended audience, intended message, knowledge required to understand the visual, unintentional messages that may be derived from the visual and missing information that may be needed to understand the visual.

RESULTS

Sixty-six examples of visual formats were identified from the literature and classified into 14 visual types. We found that there is not one single visual format that is consistently superior to others for the communication of benefit-risk information. In addition, we found that most of the drawbacks found in the visual formats could be considered general to visual communication, although some appear more relevant to specific formats and should be considered when creating visuals for different audiences depending on the exact message to be communicated.

CONCLUSION

We have arrived at recommendations for the use of visual displays for benefit-risk communication. The recommendation refers to the creation of visuals. We outline four criteria to determine audience-visual compatibility and consider these to be a key task in creating any visual. Next we propose specific visual formats of interest, to be explored further for their ability to address nine different types of benefit-risk analysis information.

Natural frequencies improve Bayesian reasoning in simple and complex inference tasks

Representing statistical information in terms of natural frequencies rather than probabilities improves performance in Bayesian inference tasks. This beneficial effect of natural frequencies has been demonstrated in a variety of applied domains such as medicine, law, and education. Yet all the research and applications so far have been limited to situations where one dichotomous cue is used to infer which of two hypotheses is true. Real-life applications, however, often involve situations where cues (e.g., medical tests) have more than one value, where more than two hypotheses (e.g., diseases) are considered, or where more than one cue is available. In Study 1, we show that natural frequencies, compared to information stated in terms of probabilities, consistently increase the proportion of Bayesian inferences made by medical students in four conditions-three cue values, three hypotheses, two cues, or three cues-by an average of 37 percentage points. In Study 2, we show that teaching natural frequencies for simple tasks with one dichotomous cue and two hypotheses leads to a transfer of learning to complex tasks with three cue values and two cues, with a proportion of 40 and 81% correct inferences, respectively. Thus, natural frequencies facilitate Bayesian reasoning in a much broader class of situations than previously thought.

Doctor, what does my positive test mean? From Bayesian textbook tasks to personalized risk communication

Most of the research on Bayesian reasoning aims to answer theoretical questions about the extent to which people are able to update their beliefs according to Bayes' Theorem, about the evolutionary nature of Bayesian inference, or about the role of cognitive abilities in Bayesian inference. Few studies aim to answer practical, mainly health-related questions, such as, "What does it mean to have a positive test in a context of cancer screening?" or "What is the best way to communicate a medical test result so a patient will understand it?". This type of research aims to translate empirical findings into effective ways of providing risk information. In addition, the applied research often adopts the paradigms and methods of the theoretically-motivated research. But sometimes it works the other way around, and the theoretical research borrows the importance of the practical question in the medical context. The study of Bayesian reasoning is relevant to risk communication in that, to be as useful as possible, applied research should employ specifically tailored methods and contexts specific to the recipients of the risk information. In this paper, we concentrate on the communication of the result of medical tests and outline the epidemiological and test parameters that affect the predictive power of a test-whether it is correct or not. Building on this, we draw up recommendations for better practice to convey the results of medical tests that could inform health policy makers (What are the drawbacks of mass screenings?), be used by health practitioners and, in turn, help patients to make better and more informed decisions.

Risk Knowledge in Relapsing Multiple Sclerosis (RIKNO 1.0)--Development of an Outcome Instrument for Educational Interventions

BACKGROUND

Adequate risk knowledge of patients is a prerequisite for shared decision making but few attempts have been made to develop assessment tools. Multiple Sclerosis (MS) is a chronic inflammatory disease of young adults with an increasing number of partially effective immunotherapies and therefore a paradigmatic disease to study patient involvement.

OBJECTIVE/METHODS

Based on an item bank of MS risk knowledge items and patient feedback including perceived relevance we developed a risk knowledge questionnaire for relapsing remitting (RR) MS (RIKNO 1.0) which was a primary outcome measure in a patient education trial (192 early RRMS patients).

RESULTS

Fourteen of the RIKNO 1.0 multiple-choice items were selected based on patient perceived relevance and item difficulty indices, and five on expert opinion. Mean item difficulty was 0.58, ranging from 0.14 to 0.79. Mean RIKNO 1.0 score increased after the educational intervention from 10.6 to 12.4 (p = 0.0003). Selected items were particularly difficult (e.g. those on absolute risk reductions of having a second relapse) and were answered correctly in only 30% of the patients, even after the intervention.

CONCLUSION

Despite its high difficulty, RIKNO 1.0 is a responsive instrument to assess risk knowledge in RRMS patients participating in educational interventions.

Communicating risk using absolute risk reduction or prolongation of life formats: cluster-randomised trial in general practice

BACKGROUND

It is important that patients are well-informed about risks and benefits of therapies to help them decide whether to accept medical therapy. Different numerical formats can be used in risk communication but It remains unclear how the different formats affect decisions made by real-life patients.

AIM

To compare the impact of using Prolongation Of Life (POL) and Absolute Risk Reduction (ARR) information formats to express effectiveness of cholesterol-lowering therapy on patients' redemptions of statin prescriptions, and on patients' confidence in their decision and satisfaction with the risk communication.

DESIGN AND SETTING

Cluster-randomised clinical trial in general practices. Thirty-four Danish GPs from 23 practices participated in a primary care-based clinical trial concerning use of quantitative effectiveness formats for risk communication in health prevention consultations.

METHOD

GPs were cluster-randomised (treating practices as clusters) to inform patients about cardiovascular mortality risk and the effectiveness of statin treatment using either POL or ARR formats. Patients' redemptions of statin prescriptions were obtained from a regional prescription database. The COMRADE questionnaire was used to measure patients' confidence in their decision and satisfaction with the risk communication.

RESULTS

Of the 240 patients included for analyses, 112 were allocated to POL information and 128 to ARR. Patients redeeming a statin prescription totalled six (5.4%) when informed using POL, and 32 (25.0%) when using ARR. The level of confidence in decision and satisfaction with risk communication did not differ between the risk formats.

CONCLUSION

Patients redeemed statin prescriptions less often when their GP communicated treatment effectiveness using POL compared with ARR.

The Influence of Math Anxiety, Math Performance, Worry, and Test Anxiety on the Iowa Gambling Task and Balloon Analogue Risk Task

Multiple studies have shown that performance on behavioral decision-making tasks, such as the Iowa Gambling Task (IGT) and Balloon Analogue Risk Task (BART), is influenced by external factors, such as mood. However, the research regarding the influence of worry is mixed, and no research has examined the effect of math or test anxiety on these tasks. The present study investigated the effects of anxiety (including math anxiety) and math performance on the IGT and BART in a sample of 137 undergraduate students. Math performance and worry were not correlated with performance on the IGT, and no variables were correlated with BART performance. Linear regressions indicated math anxiety, physiological anxiety, social concerns/stress, and test anxiety significantly predicted disadvantageous selections on the IGT during the transition from decision making under ambiguity to decision making under risk. Implications for clinical evaluation of decision making are discussed.

Can I Count on Getting Better? Association between Math Anxiety and Poorer Understanding of Medical Risk Reductions

BACKGROUND

Lower numerical ability is associated with poorer understanding of health statistics, such as risk reductions of medical treatment. For many people, despite good numeracy skills, math provokes anxiety that impedes an ability to evaluate numerical information. Math-anxious individuals also report less confidence in their ability to perform math tasks. We hypothesized that, independent of objective numeracy, math anxiety would be associated with poorer responding and lower confidence when calculating risk reductions of medical treatments.

METHODS

Objective numeracy was assessed using an 11-item objective numeracy scale. A 13-item self-report scale was used to assess math anxiety. In experiment 1, participants were asked to interpret the baseline risk of disease and risk reductions associated with treatment options. Participants in experiment 2 were additionally provided a graphical display designed to facilitate the processing of math information and alleviate effects of math anxiety. Confidence ratings were provided on a 7-point scale.

RESULTS

Individuals of higher objective numeracy were more likely to respond correctly to baseline risks and risk reductions associated with treatment options and were more confident in their interpretations. Individuals who scored high in math anxiety were instead less likely to correctly interpret the baseline risks and risk reductions and were less confident in their risk calculations as well as in their assessments of the effectiveness of treatment options. Math anxiety predicted confidence levels but not correct responding when controlling for objective numeracy. The graphical display was most effective in increasing confidence among math-anxious individuals.

CONCLUSIONS

The findings suggest that math anxiety is associated with poorer medical risk interpretation but is more strongly related to confidence in interpretations.

A qualitative study on barriers to evidence-based practice in patient counseling and advocacy in Germany

BACKGROUND

Despite the attempt to integrate evidence-based practice (EBP) in patient counseling and advocacy, there is limited knowledge on the status quo of this process in the German health care system. Our objective was to identify important determinants influencing the application of EBP in the counseling and advocacy setting in Germany.

METHODS

We carried out a qualitative study performing semi-structured expert interviews and one group discussion among n = 9 patient counselors (PCs) and patient advocates (PAs) identified via expert recommendations and by contacting relevant institutions. The interview manual was developed on the basis of a literature review on barriers/facilitators of EBP in health care delivery and a preamble oriented pyramid discussion with a multidisciplinary team. Interviews were analyzed using the Grounded Theory method. A paradigm was developed to present the interrelations between hindering and facilitating factors for EBP and the attitude towards the utilization of EBP among PAs and PCs.

RESULTS

Findings from nine face-to-face interviews and one group discussion demonstrate that by now PCs and PAs do not recognize EBP as a tool to facilitate the professionalization of patient counselors and advocates. This result is due to individual and institutional barriers such as cognitive-behavioral, professional, attitude related as well as resource and system barriers. PCs and PAs have predominantly critical attitudes towards EBP caused by a lack of trust in its reliability and by concerns regarding unfavorable effects EBP may have on the relationship with the patient and on the cooperation with physicians. A missing infrastructure of needs-based EBP training programs also discourages PCs and PAs from engaging in EBP. Despite the numerous hindering factors, there is also a growing awareness that EBP could help to improve patient counseling and advocacy. To facilitate EBP in future, needs-based training programs and health policy interventions that support interdisciplinary collaboration are required.

CONCLUSION

Although EBP among PCs and PAs is gaining importance, it is still less likely to be recognized as helpful and its application faces various barriers. More needs-based EBP training programs and health policy interventions to decrease barriers and foster interdisciplinary collaboration are necessary.

Women's Experiences of Publicly Funded Non-Invasive Prenatal Testing in Ontario, Canada: Considerations for Health Technology Policy-Making

Non-invasive prenatal testing (NIPT) via fetal DNA in maternal blood has been publicly funded in Ontario, Canada, for high-risk women since 2014. We solicited women's experiences and values related to this new health technology to describe how this test is currently being used in Ontario and to provide information about patient priorities to inform future policy decisions about the use of NIPT. Guided by constructivist grounded theory methodology, we interviewed 38 women who had diverse personal experiences with NIPT. Participants' accounts of their values for decision making about NIPT heavily relied on three mutually modulating factors: timing, accuracy, and risk. The values expressed by women conflict with the way that publicly funded NIPT has typically been implemented in Ontario. We offer recommendations for how NIPT might be integrated into prenatal care pathways in a way more consistent with women's values.

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.

Chances and risks in medical risk communication

Communication between physicians and patients in everyday life is marked by a number of disruptive factors. Apart from specific interests, mistakes, and misunderstandings on both sides, there are main factors that contribute to the risk in risk communication. Using the example of mammography screening, the current work demonstrates how the meaning of test results and the informative value of measures taken to reduce risk are often misunderstood. Finally, the current work provides examples of successful risk communication.

Statistical method use in public health research

AIMS

The content of public health research is often statistically complex. This review seeks to assess the breadth of statistical literacy required to understand this material, with a view to informing practitioners' statistical training.

METHODS

We review the statistical content of original research articles published in 2011 in four major public health journals. Categories of statistical methodologies are identified and their frequency of use recorded. Methods' "usefulness" in terms of the extent to which their understanding increases accessibility to the literature is assessed.

RESULTS

A total of 482 articles were reviewed and 30 categories of methods identified. Along with descriptive statistics (467 articles), regression analyses were also common, with logistic regression (206 articles) more than twice as prevalent as linear regression (95 articles). More complex regression models for use with clustered data were also commonly encountered, appearing in 96 articles.

CONCLUSIONS

The public health literature features a wide variety of statistical methods, some of which are advanced. To ensure the literature remains accessible, training for public health practitioners should include statistical training that maximizes breadth as well as depth of understanding.

Can informed consent to research be adapted to risk?

The current ethical and regulatory framework for research is often charged with burdening investigators and impeding socially valuable research. To address these concerns, a growing number of research ethicists argue that informed consent should be adapted to the risks of research participation. This would require less rigorous consent standards in low-risk research than in high-risk research. However, the current discussion is restricted to cases of research in which the risks of research participation are outweighed by the potential clinical benefits for the individual research participant. Furthermore, current proposals do not address the concern that risk-adapted informed consent may result in enrolling participants into research without their autonomous authorisation. In this paper, we show how the standard view of informed consent--consent as autonomous authorisation--can be adapted to risk even when the research does not have a favourable risk-benefit profile for the participant. Our argument has two important implications: first, it implies that current and proposed consent standards are not adequately calibrated to risk and, second, that consent standards also need to be adapted to factors other than risk.

Natural frequencies facilitate diagnostic inferences of managers

In Bayesian inference tasks, information about base rates as well as hit rate and false-alarm rate needs to be integrated according to Bayes' rule after the result of a diagnostic test became known. Numerous studies have found that presenting information in a Bayesian inference task in terms of natural frequencies leads to better performance compared to variants with information presented in terms of probabilities or percentages. Natural frequencies are the tallies in a natural sample in which hit rate and false-alarm rate are not normalized with respect to base rates. The present research replicates the beneficial effect of natural frequencies with four tasks from the domain of management, and with management students as well as experienced executives as participants. The percentage of Bayesian responses was almost twice as high when information was presented in natural frequencies compared to a presentation in terms of percentages. In contrast to most tasks previously studied, the majority of numerical responses were lower than the Bayesian solutions. Having heard of Bayes' rule prior to the study did not affect Bayesian performance. An implication of our work is that textbooks explaining Bayes' rule should teach how to represent information in terms of natural frequencies instead of how to plug probabilities or percentages into a formula.

On the Supposed Evidence for Libertarian Paternalism

Can the general public learn to deal with risk and uncertainty, or do authorities need to steer people’s choices in the right direction? Libertarian paternalists argue that results from psychological research show that our reasoning is systematically flawed and that we are hardly educable because our cognitive biases resemble stable visual illusions. For that reason, they maintain, authorities who know what is best for us need to step in and steer our behavior with the help of “nudges.” Nudges are nothing new, but justifying them on the basis of a latent irrationality is. In this article, I analyze the scientific evidence presented for such a justification. It suffers from narrow logical norms, that is, a misunderstanding of the nature of rational thinking, and from a confirmation bias, that is, selective reporting of research. These two flaws focus the blame on individuals’ minds rather than on external causes, such as industries that spend billions to nudge people into unhealthy behavior. I conclude that the claim that we are hardly educable lacks evidence and forecloses the true alternative to nudging: teaching people to become risk savvy.

Use of a decision aid including information on overdetection to support informed choice about breast cancer screening: a randomised controlled trial

BACKGROUND

Mammography screening can reduce breast cancer mortality. However, most women are unaware that inconsequential disease can also be detected by screening, leading to overdiagnosis and overtreatment. We aimed to investigate whether including information about overdetection of breast cancer in a decision aid would help women aged around 50 years to make an informed choice about breast screening.

METHODS

We did a community-based, parallel-group, randomised controlled trial in New South Wales, Australia, using a random cohort of women aged 48-50 years. Recruitment to the study was done by telephone; women were eligible if they had not had mammography in the past 2 years and did not have a personal or strong family history of breast cancer. With a computer program, we randomly assigned 879 participants to either the intervention decision aid (comprising evidence-based explanatory and quantitative information on overdetection, breast cancer mortality reduction, and false positives) or a control decision aid (including information on breast cancer mortality reduction and false positives). Participants and interviewers were masked to group assignment. The primary outcome was informed choice (defined as adequate knowledge and consistency between attitudes and screening intentions), which we assessed by telephone interview about 3 weeks after random allocation. The primary outcome was analysed in all women who completed the relevant follow-up interview questions fully. This trial is registered with the Australian New Zealand Clinical Trials Registry, number ACTRN12613001035718.

FINDINGS

Between January, 2014, and July, 2014, 440 women were allocated to the intervention group and 439 were assigned to the control group. 21 women in the intervention group and 20 controls were lost to follow-up; a further ten women assigned to the intervention and 11 controls did not answer all questions on attitudes. Therefore, 409 women in the intervention group and 408 controls were analysed for the primary outcome. 99 (24%) of 409 women in the intervention group made an informed choice compared with 63 (15%) of 408 in the control group (difference 9%, 95% CI 3-14; p=0·0017). Compared with controls, more women in the intervention group met the threshold for adequate overall knowledge (122/419 [29%] vs 71/419 [17%]; difference 12%, 95% CI 6-18; p<0·0001), fewer women expressed positive attitudes towards screening (282/409 [69%] vs 340/408 [83%]; 14%, 9-20; p<0·0001), and fewer women intended to be screened (308/419 [74%] vs 363/419 [87%]; 13%, 8-19; p<0·0001). When conceptual knowledge alone was considered, 203 (50%) of 409 women in the intervention group made an informed choice compared with 79 (19%) of 408 in the control group (p<0·0001).

INTERPRETATION

Information on overdetection of breast cancer provided within a decision aid increased the number of women making an informed choice about breast screening. Becoming better informed might mean women are less likely to choose screening.

FUNDING

Australian National Health and Medical Research Council.

The amplification of risk in experimental diffusion chains

Understanding how people form and revise their perception of risk is central to designing efficient risk communication methods, eliciting risk awareness, and avoiding unnecessary anxiety among the public. However, public responses to hazardous events such as climate change, contagious outbreaks, and terrorist threats are complex and difficult-to-anticipate phenomena. Although many psychological factors influencing risk perception have been identified in the past, it remains unclear how perceptions of risk change when propagated from one person to another and what impact the repeated social transmission of perceived risk has at the population scale. Here, we study the social dynamics of risk perception by analyzing how messages detailing the benefits and harms of a controversial antibacterial agent undergo change when passed from one person to the next in 10-subject experimental diffusion chains. Our analyses show that when messages are propagated through the diffusion chains, they tend to become shorter, gradually inaccurate, and increasingly dissimilar between chains. In contrast, the perception of risk is propagated with higher fidelity due to participants manipulating messages to fit their preconceptions, thereby influencing the judgments of subsequent participants. Computer simulations implementing this simple influence mechanism show that small judgment biases tend to become more extreme, even when the injected message contradicts preconceived risk judgments. Our results provide quantitative insights into the social amplification of risk perception, and can help policy makers better anticipate and manage the public response to emerging threats.

Threshold-free measures for assessing the performance of medical screening tests

Background

The area under the receiver operating characteristic curve (AUC) is frequently used as a performance measure for medical tests. It is a threshold-free measure that is independent of the disease prevalence rate. We evaluate the utility of the AUC against an alternate measure called the average positive predictive value (AP), in the setting of many medical screening programs where the disease has a low prevalence rate.

Methods

We define the two measures using a common notation system and show that both measures can be expressed as a weighted average of the density function of the diseased subjects. The weights for the AP include prevalence in some form, but those for the AUC do not. These measures are compared using two screening test examples under rare and common disease prevalence rates.

Results

The AP measures the predictive power of a test, which varies when the prevalence rate changes, unlike the AUC, which is prevalence independent. The relationship between the AP and the prevalence rate depends on the underlying screening/diagnostic test. Therefore, the AP provides relevant information to clinical researchers and regulators about how a test is likely to perform in a screening population.

Conclusion

The AP is an attractive alternative to the AUC for the evaluation and comparison of medical screening tests. It could improve the effectiveness of screening programs during the planning stage.

[Are German information materials on colorectal cancer screening understandable or do they fail? Rating of health information by users with different educational backgrounds]

Evidence-based patient information is an essential part of decision making in health issues. A qualitative study was conducted to examine whether consumers consider the health information on colorectal cancer screening in Germany helpful in supporting their decision making. In this study, eight texts from different German authors about colorectal cancer screening were evaluated with a criteria-based selection. The texts were tested for understandability, structure, design, and effect on readers. Thirteen semi-structured focus groups were formed including 59 higher-educated and 15 lower-educated testers, 46 % of them being male with a mean age of 62.9 years. The transcripts were analyzed by content-analytic assessment. The testers provided detailed comments on the content and design of the texts. They revealed inaccuracies and suggested improvements of the texts. The testers differed from each other in terms of the intensity of their participation in the discussions and comprehension of the material. The reception of the flyers and brochures varied according to the educational level of the testers. Lower-educated testers often skipped passages of texts about risks as well as passages containing numbers and graphics. The texts had different effects on the testers, regardless of the level of education. If adverse effects were presented, some testers became scared while others were reassured because they felt informed. Most of the testers appreciated a call for participation as a central message of the text. Sometimes, if there was no clear appeal to attend the screening, the testers even asked for it. The recently introduced political strategy of promoting an informed choice is applied to an unprepared population who was used to getting a clear yes-or-no recommendation. Thus, at first, the population has to learn how to make an informed choice. This topic must be addressed and taken into account in the process of developing health information. Since this is not always the case, we conclude that current materials are limited in their contribution toward the decision of attending CRC screening.

Good fences make for good neighbors but bad science: a review of what improves Bayesian reasoning and why

Bayesian reasoning, defined here as the updating of a posterior probability following new information, has historically been problematic for humans. Classic psychology experiments have tested human Bayesian reasoning through the use of word problems and have evaluated each participant’s performance against the normatively correct answer provided by Bayes’ theorem. The standard finding is of generally poor performance. Over the past two decades, though, progress has been made on how to improve Bayesian reasoning. Most notably, research has demonstrated that the use of frequencies in a natural sampling framework—as opposed to single-event probabilities—can improve participants’ Bayesian estimates. Furthermore, pictorial aids and certain individual difference factors also can play significant roles in Bayesian reasoning success. The mechanics of how to build tasks which show these improvements is not under much debate. The explanations for why naturally sampled frequencies and pictures help Bayesian reasoning remain hotly contested, however, with many researchers falling into ingrained “camps” organized around two dominant theoretical perspectives. The present paper evaluates the merits of these theoretical perspectives, including the weight of empirical evidence, theoretical coherence, and predictive power. By these criteria, the ecological rationality approach is clearly better than the heuristics and biases view. Progress in the study of Bayesian reasoning will depend on continued research that honestly, vigorously, and consistently engages across these different theoretical accounts rather than staying “siloed” within one particular perspective. The process of science requires an understanding of competing points of view, with the ultimate goal being integration.