Improving understanding of adjuvant therapy options by using simpler risk graphics§

Authors

  • Brian J. Zikmund-Fisher PhD,

    Corresponding author
    1. Health Services Research & Development Center for Clinical Management Research, Veterans Administration Ann Arbor Healthcare System, Ann Arbor, Michigan
    2. Center for Behavioral and Decision Sciences in Medicine, Ann Arbor, Michigan
    3. Division of General Internal Medicine, University of Michigan, Ann Arbor, Michigan
    • Center for Behavioral and Decision Sciences in Medicine, 300 North Ingalls Building, Room 7C27, Ann Arbor, MI 48109-5429
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    • Fax: (734) 936-8944

  • Angela Fagerlin PhD,

    1. Health Services Research & Development Center for Clinical Management Research, Veterans Administration Ann Arbor Healthcare System, Ann Arbor, Michigan
    2. Center for Behavioral and Decision Sciences in Medicine, Ann Arbor, Michigan
    3. Division of General Internal Medicine, University of Michigan, Ann Arbor, Michigan
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  • Peter A. Ubel MD

    1. Health Services Research & Development Center for Clinical Management Research, Veterans Administration Ann Arbor Healthcare System, Ann Arbor, Michigan
    2. Center for Behavioral and Decision Sciences in Medicine, Ann Arbor, Michigan
    3. Division of General Internal Medicine, University of Michigan, Ann Arbor, Michigan
    4. Department of Psychology, University of Michigan, Ann Arbor, Michigan
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  • Presented at the Annual Meeting of the Society for Medical Decision Making, Philadelphia, Pennsylvania, October 20, 2008.

  • The funding agreements ensured the authors' independence in designing the study, interpreting the data, and publishing the report.

  • §

    The views expressed in this article are those of the authors and do not necessarily reflect the position or policy of the Department of Veterans Affairs.

  • The authors would like to acknowledge Ellen Peters, Isaac Lipkus, and Mick Couper for helpful discussions and comments; Rosemarie Pitsch for her project management; and Bob Burbach and Aaron Pearlman for creating the risk graphics and for programming, testing, and implementing the survey.

  • This article is a US Government work and, as such, is in the public domain in the United States of America.

Abstract

BACKGROUND:

To help oncologists and breast cancer patients make informed decisions about adjuvant therapies, online tools such as Adjuvant! provide tailored estimates of mortality and recurrence risks. However, the graphical format used to display these results (a set of 4 horizontal stacked bars) may be suboptimal. The authors tested whether using simpler formats would improve comprehension of the relevant risk statistics.

METHODS:

A total of 1619 women, aged 40-74 years, completed an Internet-administered survey vignette about adjuvant therapy decisions for a patient with an estrogen receptor-positive tumor. Participants were randomized to view 1 of 4 risk graphics, a base version that mirrored the Adjuvant! format, an alternate graph that showed only 2 options (those that included hormonal therapy), a graph that used a pictograph format, or a graph that included both changes. Outcome measures included comprehension of key statistics, time required to complete the task, and graph-perception ratings.

RESULTS:

The simplifying format changes significantly improved comprehension, especially when both changes were implemented together. Compared with participants who viewed the base 4-option bar graph, respondents who, instead, viewed a 2-option pictograph version were more accurate when they reported the incremental risk reduction achievable from adding chemotherapy to hormonal therapy (77% vs 51%; P< .001), answered that question more quickly (median time, 28 seconds vs 42 seconds; P< .001), and liked the graph more (mean, 7.67 vs 6.88; P< .001).

CONCLUSIONS:

Although most patients will only view risk calculators such as Adjuvant! in consultation with their clinicians, simplifying design graphics could significantly improve patients' comprehension of statistics essential for informed decision making about adjuvant therapies. Cancer 2008. Published 2008 by the American Cancer Society.

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