Odette Wegwarth

Numbers Can Be Worth a Thousand Pictures: Individual Differences in Understanding Graphical and Numerical Representations of Health-Related Information

OBJECTIVE Informed medical decision making requires comprehending statistical information. We aimed to improve the understanding of conveying health-related statistical information with graphical representations compared with numerical representations. First, we investigated whether the iconicity of representations (i.e., their abstractness vs. concreteness) affected comprehension and recall of statistical information. Second, we investigated whether graph literacy helps to identify individuals who comprehend graphical representations better than numerical representations. METHOD Participants (N = 275) were randomly assigned to receive different representations of health-related statistical information, ranging from very low iconicity (numbers) to very high iconicity (icon arrays including photographs). Comprehension and recall of the information were assessed. Additionally, participants rated the accessibility of the information and the attractiveness of the representation. Graph literacy was assessed by means of a recently developed scale. RESULTS The only difference between representations that affected comprehension and recall was the difference between graphics and numbers; the actual level of iconicity of graphics did not matter. Individuals with high graph literacy had better comprehension and recall when presented with graphics instead of numbers, and they rated graphical information as more accessible than numerical information, whereas the reverse was true for individuals with low graph literacy, F(4, 185) = 2.60, p = .04, η(p)(²) = .05, and F(4, 245) = 2.71, p = .03, η(p)(2) = .04, respectively. Both groups judged graphical representations as more attractive than numerical representations. CONCLUSION An assessment of graph literacy distinguished individuals who are best informed with graphical representations of statistical information from those who are better informed with numerical representations.

Smart strategies for doctors and doctors-in-training: heuristics in medicine

Context  How do doctors make sound decisions when confronted with probabilistic data, time pressures and a heavy workload? One theory that has been embraced by many researchers is based on optimisation, which emphasises the need to integrate all information in order to arrive at sound decisions. This notion makes heuristics, which use less than complete information, appear as second‐best strategies. In this article, we challenge this pessimistic view of heuristics.

Misleading communication of risk

Editors should enforce transparent reporting in abstracts

“There is nothing to worry about”: Gynecologists’ counseling on mammography

OBJECTIVE In Germany, approximately 10 million women between the ages of 50 and 69 are eligible for biennial mammography screening. Mammography is at the center of much controversy, however, which means gynecologists must provide women considering mammography with sufficient and transparent information. The present study analyzed the information gynecologists share with a person seeking advice about the benefit and harms of mammography screening. METHOD To receive realistic data, we called 20 gynecologists practicing in different large cities across Germany and took telephone counseling sessions on the benefit and harms of mammography. RESULTS The majority of gynecologists described mammography as safe and scientifically well grounded. Harms were rarely mentioned or described as negligible. A minority of gynecologists provided numerical information; when they did, they often quantified the benefit using relative risk reduction and harms using absolute risk increase. CONCLUSION A sample of German gynecologists was not able to correctly and transparently communicate the benefit and harms of mammography screening to a patient. PRACTICE IMPLICATION Gynecologists should be taught how to understand and transparently explain medical risk information in simple terms.

Deceiving Numbers: Survival Rates and Their Impact on Doctors’ Risk Communication

Background. Increased 5-y survival for screened patients is often inferred to mean that fewer patients die of cancer. However, due to several biases, the 5-y survival rate is a misleading metric for evaluating a screening’s effectiveness. If physicians are not aware of these issues, informed screening counseling cannot take place. Methods. Two questionnaire versions (“group” and “time”) presented 4 conditions: 5-y survival (5Y), 5-y survival and annual disease-specific mortality (5YM), annual disease-specific mortality (M), and 5-y survival, annual disease-specific mortality, and incidence (5YMI). Questionnaire version “time” presented data as a comparison between 2 time points and version “group” as a comparison between a screened and an unscreened group. All data were based on statistics for the same cancer site (prostate). Outcome variables were the recommendation of screening, reasoning behind recommendation, judgment of the screening’s effectiveness, and, if judged effective, a numerical estimate of how many fewer people out of 1000 would die if screened regularly. After randomized allocation, 65 German physicians in internal medicine and its subspecialities completed either of the 2 questionnaire versions. Results. Across both versions, 66% of the physicians recommended screening when presented with 5Y, but only 8% of the same physicians made the recommendation when presented with M (5YM: 31%; 5YMI: 55%). Also, 5Y made considerably more physicians (78%) judge the screening to be effective than any other condition (5YM: 31%; M: 5%; 5YMI: 49%) and led to the highest overestimations of benefit. Conclusion. A large number of physicians erroneously based their screening recommendation and judgment of screening’s effectiveness on the 5-y survival rate. Results show that reporting disease-specificmortality rates can offer a simple solution to physicians’ confusion about the real effect of screening.

Naturalistic Heuristics for Decision Making

Over the last 20 years, both naturalistic decision making and fast and frugal heuristics programs have radically broken with mainstream decision science, moving beyond the confines of artificial tasks and safe academic laboratories. We document commonalities of these programs and discuss ways in which a synthesis could contribute to a more relevant, precise, predictive, and effective decision science. We begin by reviewing the common roots and philosophies of the two programs, such as their respect for the capable decision maker and their acknowledgment of the importance of task ecology. We then identify four specific areas of synergetic potential, including ecological rationality and metacognition. Our review culminates in a case study of naturalistic heuristics based on a particular class of fast and frugal heuristics. These fast and frugal trees provide examples of effective, well-specified decision-making algorithms applied in a naturalistic domain: emergency medical diagnosis. By leveraging the strengths of each program, we point out some of the ways in which more sustainable progress can be fostered on issues that matter the most—for example, decisions that save and transform lives.

Five year survival rates can mislead

Medical trainers and journals need to help get the message across

Design and usability of heuristic-based deliberation tools for women facing amniocentesis

Background  Evidence suggests that in decision contexts characterized by uncertainty and time constraints (e.g. health‐care decisions), fast and frugal decision‐making strategies (heuristics) may perform better than complex rules of reasoning.

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.

The Phenomenology of the Diagnostic Process: A Primary Care-Based Survey.

Background. While dichotomous tasks and related cognitive strategies have been extensively researched in cognitive psychology, little is known about how primary care practitioners (general practitioners [GPs]) approach ill-defined or polychotomous tasks and how valid or useful their strategies are. Objective. To investigate cognitive strategies used by GPs for making a diagnosis. Methods. In a cross-sectional study, we videotaped 282 consultations, irrespective of presenting complaint or final diagnosis. Reflective interviews were performed with GPs after each consultation. Recordings of consultations and GP interviews were transcribed verbatim and analyzed using a coding system that was based on published literature and systematically checked for reliability. Results. In total, 134 consultations included 163 diagnostic episodes. Inductive foraging (i.e., the initial, patient-guided search) could be identified in 91% of consultations. It contributed an average 31% of cues obtained by the GP in 1 consultation. Triggered routines and descriptive questions occurred in 38% and 84% of consultations, respectively. GPs resorted to hypothesis testing, the hallmark of the hypothetico-deductive method, in only 39% of consultations. Limitations. Video recordings and interviews presumably interfered with GPs’ behavior and accounts. GPs might have pursued more hypotheses and collected more information than usual. Conclusions. The testing of specific disease hypotheses seems to play a lesser role than previously thought. Our data from real consultations suggest that GPs organize their search for information in a skillfully adapted way. Inductive foraging, triggered routines, descriptive questions, and hypotheses testing are essential building blocks to make a diagnosis in the generalist setting.