Clinical Implications of Numeracy: Theory and Practice

Abstract

Background Low 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. Purpose We provide an overview of research on health numeracy and discuss its implications in clinical contexts. Conclusions Low 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.

Inaccurate Risk Perceptions and Individualized Risk Estimates by Patients with Type 2 Diabetes

“…Similar beliefs have been noted in other contexts, such as cancer prevention and screening. 18 A substantial proportion of our participants did not understand personalized risk information when presented in 2 different formats suggested by previous literature 6,[11][12][13][14]16 ; some did not understand even the order of risks indicated by their personalized data. Few reported that specific biomedical information had motivated behavior change in the past.…”

“…Initial group participants were randomized to have risks presented as either a set of horizontal bar graphs (on one page) or a set of crowd charts (on separate pages), with a 10 ϫ 10 array of items representing the relevant outcome and the probability of experiencing the outcome represented by shading the relevant number of figures, to study whether one of these evidence-supported representations 6,[11][12][13][14][15][16] seemed to be preferable. For mortality, we developed an array of pictures of 100 people representing a broad range of ages and racial/ethnic backgrounds.…”

Shared Decision Making in Oncology Practice: What Do Oncologists Need to Know?

“…Efforts to communicate quantitative data available from clinical trials research can be complicated by the limited numeracy (ability to work with numbers) and health literacy skills of many patients [34]. To facilitate understanding, statistics about risks and benefits can be framed in terms of frequencies (e.g., "Our best estimate is that x of 100 people like you will have a recurrence without having this treatment, compared with x of 100 people who will have a recurrence after having this treatment"), with visual aids or graphics if available (Fig.…”

The Meaning of Numbers in Health: Exploring Health Numeracy in a Mexican-American Population

“…Several conceptual frameworks have been developed to outline the range of skills comprising the construct of health numeracy and their relationship to the process of health communication and medical decision making [1][2][3][4][5][6][7] . However, cross-cultural methods have generally not been used either in the development of these frameworks or in the development of scales to measure this construct.…”