Effects of graphic presentation on understanding medical risks and benefits among Japanese adults

Abstract

Abstract: The purpose of this study was to identify the method of presentation (text, bar graphs, or pictographs) that best enhances the understanding of medical risk information among Japanese adults. We also investigated the effect of graphic format on understanding by differences in numeracy. This is the first study conducted in Japan to clarify understanding the risks and benefits of treatment. Participants were randomized to receive numerical information about the risks and benefits of a hypothetical medical treatment in one of three formats: text, bar graphs, or pictographs. The main outcome variables were adequate verbatim and adequate gist understanding. In total, 1062 individuals (text, 354; bar graphs, 358; and pictographs 350) were included in the analysis. Pictographs and bar graphs did not show significant differences from text in conferring verbatim information. However, pictographs significantly differed from text in conferring gist information (odds ratio [OR] 1.567, 95% confidence interval [CI] 1.097–2.237), but bar graphs did not significantly differ from text (OR 1.390, 95%CI 0.983–1.964). Numeracy was the factor most strongly associated with adequate verbatim and gist understanding. Our results suggest that although pictographs appear to be an effective option, their effectiveness is limited to people with higher numeracy and people with lower numeracy may have little benefit from pictographs.

Keywords:

• risks and benefits
• graphic presentation
• pictographs
• numeracy
• understanding

PUBLIC INTEREST STATEMENT

Patients are increasingly being asked to make complex decisions about cancer screening, prevention, and treatment. For patients to make informed medical decisions, providers must effectively communicate evidence about benefits and harms, and must ensure that patients can understand the risks and benefits of treatments and make trade-offs between risks and benefits.

This study explored recommendations for how healthcare providers and health educators can best communicate complex medical risk information to patients. This study aimed to identify the method of presentation (text, bar graphs, or pictographs) that best enhances the understanding of medical risk information among Japanese adults, and clarify the effective understanding of graphic format by differences in numeracy. Our results showed that although pictographs appear to be an effective option overall, they are most effective for people with higher numeracy and people with lower numeracy may gain little benefit from pictographs.

Acknowledgements

This work was supported by Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (JSPS) KAKENHI Grant Number 16H05569. We thank Edanz Group (https://en-author-services.edanz.com/ac) for editing a draft of this manuscript.

Additional information

Funding

This work was supported by a Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (JSPS) KAKENHI Grant Number 16H05569.

Notes on contributors

Hitomi Danya

Hitomi Danya is a nurse and PhD student in Health Communication.

Her research focuses on finding ways to communicate healthcare risk information correctly and clearly to patients and the public. She aims to provide patient-centered information that is not self-satisfying or one-sided, and make risk information accessible to all people regardless of their literacy level. She also hopes to support people who are faced with healthcare choices so that they can make choices that are truly their own and based on correct information and their own values.

This paper is a part of her master’s thesis and was written with the support of Dr. Nakayama and Dr. Yonekura.