Isaac M. Lipkus

General Performance on a Numeracy Scale among Highly Educated Samples

Background. Numeracy, how facile people are with basic probability and mathematical concepts, is associated with how people perceive health risks. Performance on simple numeracy problems has been poor among populations with little as well as more formal education. Here, we examine how highly educated participants performed on a general and an expanded numeracy scale. The latter was designed within the context of health risks. Method. A total of 463 men and women aged 40 and older completed a 3-item general and an expanded 7-item numeracy scale. The expanded scale assessed how well people 1) differentiate and perform simple mathematical operations on risk magnitudes using percentages and proportions, 2) convert percentages to proportions, 3) convert proportions to percentages, and 4) convert probabilities to proportions. Results. On average, 18% and 32% of participants correctly answered all of the general and expanded numeracy scale items. Approximately 16% to 20% incorrectly answered the most straightforward questions pertaining to risk magnitudes (e.g., Which represents the larger risk: 1%, 5%, or 10%?). A factor analysis revealed that the general and expanded risk numeracy items tapped the construct of global numeracy. Conclusions. These results suggest that even highly educated participants have difficulty with relatively simple numeracy questions, thus replicating in part earlier studies. The implication is that usual strategies for communicating numerical risk may be flawed. Methods and consequences of communicating health risk information tailored to a person’s level of numeracy should be explored further.

Numeric, Verbal, and Visual Formats of Conveying Health Risks: Suggested Best Practices and Future Recommendations

Perception of health risk can affect medical decisions and health behavior change. Yet the concept of risk is a difficult one for the public to grasp. Whether perceptions of risk affect decisions and behaviors often relies on how messages of risk magnitudes (i.e., likelihood) are conveyed. Based on expert opinion, this article offers, when possible, best practices for conveying magnitude of health risks using numeric, verbal, and visual formats. This expert opinion is based on existing empirical evidence, review of papers and books, and consultations with experts in risk communication. This article also discusses formats to use pertaining to unique risk communication challenges (e.g., conveying small-probability events, interactions). Several recommendations are suggested for enhancing precision in perception of risk by presenting risk magnitudes numerically and visually. Overall, there are little data to suggest best practices for verbal communication of risk magnitudes. Across the 3 formats, few overall recommendations could be suggested because of 1) lack of consistency in testing formats using the same outcomes in the domain of interest, 2) lack of critical tests using randomized controlled studies pitting formats against one another, and 3) lack of theoretical progress detailing and testing mechanisms why one format should be more efficacious in a specific context to affect risk magnitudes than others. Areas of future research are provided that it is hoped will help illuminate future best practices.

The construction and preliminary validation of a global belief in a just world scale and the exploratory analysis of the multidimensional belief in a just world scale

Abstract The goal of the present study was to create and validate a global belief in a just world scale and to assess the psychometric properties of the multidimensional just world scale using subjects in the United States. The desirable psychometric properties of the global belief in a just world scale make it a viable alternative to Rubin and Peplaus ( Journal of Social Issues, 31 , 65–90, 1975) just world scale. Analysis of the multidimensional just world scale suggests that the scale consists of three factors—interpersonal justice, socio-political justice, and cynicism/fatalism—and has poor psychometric properties. Both the global and multidimensional belief in a just world scale correlate positively with trust and internal locus of control.

Clinical Implications of Numeracy: Theory and Practice

BackgroundLow numeracy is pervasive and constrains informed patient choice, reduces medication compliance, limits access to treatments, impairs risk communication, and affects medical outcomes; therefore, it is incumbent upon providers to minimize its adverse effects.PurposeWe provide an overview of research on health numeracy and discuss its implications in clinical contexts.ConclusionsLow numeracy cannot be reliably inferred on the basis of patients’ education, intelligence, or other observable characteristics. Objective and subjective assessments of numeracy are available in short forms and could be used to tailor health communication. Low scorers on these assessments are subject to cognitive biases, irrelevant cues (e.g., mood), and sharper temporal discounting. Because prevention of the leading causes of death (e.g., cancer and cardiovascular disease) depends on taking action now to prevent serious consequences later, those low in numeracy are likely to require more explanation of risk to engage in prevention behaviors. Visual displays can be used to make numerical relations more transparent, and different types of displays have different effects (e.g., greater risk avoidance). Ironically, superior quantitative processing seems to be achieved by focusing on qualitative gist and affective meaning, which has important implications for empowering patients to take advantage of the evidence in evidence-based medicine.

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

BackgroundMaking evidence-based decisions often requires comparison of two or more options. Research-based evidence may exist which quantifies how likely the outcomes are for each option. Understanding these numeric estimates improves patients’ risk perception and leads to better informed decision making. This paper summarises current “best practices” in communication of evidence-based numeric outcomes for developers of patient decision aids (PtDAs) and other health communication tools.MethodAn expert consensus group of fourteen researchers from North America, Europe, and Australasia identified eleven main issues in risk communication. Two experts for each issue wrote a “state of the art” summary of best evidence, drawing on the PtDA, health, psychological, and broader scientific literature. In addition, commonly used terms were defined and a set of guiding principles and key messages derived from the results.ResultsThe eleven key components of risk communication were: 1) Presenting the chance an event will occur; 2) Presenting changes in numeric outcomes; 3) Outcome estimates for test and screening decisions; 4) Numeric estimates in context and with evaluative labels; 5) Conveying uncertainty; 6) Visual formats; 7) Tailoring estimates; 8) Formats for understanding outcomes over time; 9) Narrative methods for conveying the chance of an event; 10) Important skills for understanding numerical estimates; and 11) Interactive web-based formats. Guiding principles from the evidence summaries advise that risk communication formats should reflect the task required of the user, should always define a relevant reference class (i.e., denominator) over time, should aim to use a consistent format throughout documents, should avoid “1 in x” formats and variable denominators, consider the magnitude of numbers used and the possibility of format bias, and should take into account the numeracy and graph literacy of the audience.ConclusionA substantial and rapidly expanding evidence base exists for risk communication. Developers of tools to facilitate evidence-based decision making should apply these principles to improve the quality of risk communication in practice.

American Society of Clinical Oncology Technology Assessment of Pharmacologic Interventions for Breast Cancer Risk Reduction Including Tamoxifen, Raloxifene, and Aromatase Inhibition

OBJECTIVE To update an evidence-based technology assessment of chemoprevention strategies for breast cancer risk reduction. POTENTIAL INTERVENTIONS: Tamoxifen, raloxifene, aromatase inhibition, and fenretinide. OUTCOMES Outcomes of interest include breast cancer incidence, breast cancer-specific survival, overall survival, and net health benefit. EVIDENCE A comprehensive, formal literature review was conducted for relevant topics. Testimony was collected from invited experts and interested parties. The American Society of Clinical Oncology (ASCO) prescribed technology assessment procedure was followed. VALUES More weight was given to published randomized trials. BENEFITS/HARMS: A womans decision regarding breast cancer risk reduction strategies is complex and will depend on the importance and weight attributed to information regarding both cancer- and noncancer-related risks and benefits. CONCLUSIONS For women with a defined 5-year projected breast cancer risk of > or= 1.66%, tamoxifen (at 20 mg/d for 5 years) may be offered to reduce their risk. Risk/benefit models suggest that greatest clinical benefit with least side effects is derived from use of tamoxifen in younger (premenopausal) women (who are less likely to have thromboembolic sequelae and uterine cancer), women without a uterus, and women at higher breast cancer risk. Data do not as yet suggest that tamoxifen provides an overall health benefit or increases survival. In all circumstances, tamoxifen use should be discussed as part of an informed decision-making process with careful consideration of individually calculated risks and benefits. Use of tamoxifen combined with hormone replacement therapy or use of raloxifene, any aromatase inhibitor or inactivator, or fenretinide to lower the risk of developing breast cancer is not recommended outside of a clinical trial setting. This technology assessment represents an ongoing process and recommendations will be updated in a timely matter. VALIDATION The conclusions were endorsed by the ASCO Health Services Research Committee and the ASCO Board of Directors.

Psychological impact of diagnosis and risk reduction among cancer survivors

Life‐threatening health events prompt psychological distress that may motivate individuals to reduce health risks. If so, interventions timed to take advantage of these ‘teachable moments’ could be particularly effective. To explore this association, early stage prostate and breast cancer patients were identified from a hospital‐based tumor registry within 6 years of diagnosis. These patients (n=920) completed a mailed survey assessing the Horowitz impact of events scale, risk behaviors and readiness to change the behaviors. Breast cancer patients, younger patients and those reporting poor health status reported the greatest impact of the cancer diagnosis. Impact was inversely associated with time from diagnosis for prostate, but not breast cancer patients. Prostate patients who reported exercising regularly had lower impact scores than those who were not exercising (medians: 0.13 vs 0.56, respectively; p=0.02). Breast patients who were eating five or more fruits and vegetables reported lower impact scores than those who were not eating the recommended servings (0.75 vs 1.06, respectively; p=0.03). Breast patients who were non‐smokers reported lower impact scores than smokers (0.88 vs 1.31, respectively; p=0.02). Prospective studies are needed to understand the psychological impact of cancer diagnosis and how it might facilitate or impede the adoption of health promoting behaviors. Copyright

Understanding the Role of Numeracy in Health: Proposed Theoretical Framework and Practical Insights

Numeracy—that is, how facile people are with mathematical concepts and their applications—is gaining importance in medical decision making and risk communication. This article proposes six critical functions of health numeracy. These functions are integrated into a theoretical framework on health numeracy that has implications for risk communication and medical decision-making processes. The authors examine practical underpinnings for targeted interventions aimed at improving such processes as a function of health numeracy. They hope that the proposed functions and theoretical framework will spur more research to determine how an understanding of health numeracy can lead to more effective communication and decision outcomes.

Personality measures as predictors of smoking initiation and cessation in the UNC Alumni Heart Study.

MMPI data collected from a sample of college men and women during 1964-1967 were used to predict smoking initiation and cessation over a 20-year follow-up period. People who subsequently began smoking were more rebellious, impulsive, sensation seeking, and hostile; were less likely to present a positive self-image; and were socially extraverted while in college. People who continued to smoke 20 years later were more hostile and sensation seeking. The personality variables that predicted smoking initiation and cessation were the same for men and women. Discussion centers on the potential role of hostility as a predictor of smoking cessation.

Communicating Genetic and Genomic Information: Health Literacy and Numeracy Considerations

Genomic research is transforming our understanding of the role of genes in health and disease. These advances, and their application to common diseases that affect large segments of the general population, suggest that researchers and practitioners in public health genomics will increasingly be called upon to translate genomic information to individuals with varying levels of health literacy and numeracy. This paper discusses the current state of research regarding public understanding of genetics and genomics, the influence of health literacy and numeracy on genetic communication, and behavioral responses to genetic and genomic information. The existing research suggests that members of the general public have some familiarity with genetic and genomic terms but have gaps in understanding of underlying concepts. Findings from the limited research base to date indicate that health literacy affects understanding of print and oral communications about genetic and genomic information. Numeracy is also likely to be an important predictor of being able to understand and apply this information, although little research has been conducted in this area to date. In addition, although some research has examined behavior change in response to the receipt of information about genetic risk for familial disorders and genomic susceptibility to common, complex diseases, the effects of health literacy and numeracy on these responses have not been examined. Potential areas in which additional research is needed are identified and practical suggestions for presenting numeric risk information are outlined. Public health genomics researchers and practitioners are uniquely positioned to engage in research that explores how different audiences react to and use genomic risk information.