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The Scientific World Journal
Volume 2012, Article ID 562637, 10 pages
Review Article

Using Visual Aids to Improve Communication of Risks about Health: A Review

1Department of Experimental Psychology, University of Granada, 18071 Granada, Spain
2Center for Adaptive Behavior and Cognition, Max Planck Institute for Human Development, 14195 Berlin, Germany
3Department of Cognitive and Learning Sciences, Michigan Technological University, Houghton, MI 49931, USA

Received 31 October 2011; Accepted 14 December 2011

Academic Editor: Marc A. Adams

Copyright © 2012 Rocio Garcia-Retamero et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Recent research has shown that patients frequently experience difficulties understanding health-relevant numerical concepts. A prominent example is denominator neglect, or the tendency to pay too much attention to numerators in ratios (e.g., number of treated patients who died) with insufficient attention to denominators (e.g., overall number of treated patients). Denominator neglect can lead to inaccurate assessments of treatment risk reduction and thus can have important consequences for decisions about health. Here, we reviewed a series of studies investigating (1) different factors that can influence patients’ susceptibility to denominator neglect in medical decision making—including numerical or language-related abilities; (2) the extent to which denominator neglect can be attenuated by using visual aids; and (3) a factor that moderates the effectiveness of such aids (i.e., graph literacy). The review spans probabilistic national U.S. and German samples, as well as immigrant (i.e., Polish people living in the United Kingdom) and undergraduate samples in Spain. Theoretical and prescriptive implications are discussed.