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Using survival curve comparisons to inform patient decision making

Can a practice exercise improve understanding?

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Abstract

BACKGROUND: Patients often face medical decisions that involve outcomes that occur and change over time. Survival curves are a promising communication tool for patient decision support because they present information about the probability of an outcome over time in a simple graphic format. However, previous studies of survival curves did not measure comprehension, used face-to-face explanations, and focused on a VA population.

METHODS: In this study, 246 individuals awaiting jury duty at the Philadelphia County Courthouse were randomized to receive one of two questionnaires. The control group received a questionnaire describing two hypothetical treatments and a graph with two survival curves showing the outcomes of each treatment. The practice group received the same questionnaire preceded by a practice exercise asking questions about a graph containing a single curve. Subjects’ ability to interpret survival from a curve and ability to calculate change in survival over time were measured.

RESULTS: Understanding of survival at a single point in time from a graph containing two survival curves was high overall, and was improved by the use of a single curve practice exercise. With a practice exercise, subjects were over 80% accurate in interpreting survival at a single point in time. Understanding of changes in survival over time was lower overall, and was not improved by the use of a practice exercise. With or without a practice exercise, subjects were only 55% accurate in calculating changes in survival.

CONCLUSION: The majority of the general public can interpret survival at a point in time from self-administered survival curves. This understanding is improved by a single curve practice exercise. However, a significant proportion of the general public cannot calculate change in survival over time. Further research is necessary to determine the effectiveness of survival curves in improving risk communication and patient decision making.

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Authors and Affiliations

  1. the Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia

    Katrina Armstrong MD, MSc, Genevieve FitzGerald BA, J. Sanford Schwartz MD & Peter A. Ubel MD

  2. the Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania School of Medicine, Philadelphia

    Katrina Armstrong MD, MSc & J. Sanford Schwartz MD

  3. the Leonard Davis Institute of Health Economics, Univesity of Pennsylvania, Philadelphia

    Katrina Armstrong MD, MSc, J. Sanford Schwartz MD & Peter A. Ubel MD

  4. the University of Pennsylvania Cancer Center, Philadelphia

    Katrina Armstrong MD, MSc, J. Sanford Schwartz MD & Peter A. Ubel MD

  5. the Philadelphia Vaterans’ Affairs Medical Center, Philadelphia

    Peter A. Ubel MD

Authors
  1. Katrina Armstrong MD, MSc
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  2. Genevieve FitzGerald BA
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  3. J. Sanford Schwartz MD
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  4. Peter A. Ubel MD
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Corresponding author

Correspondence to Katrina Armstrong MD, MSc.

Additional information

This work was supported by Grant BC971623 from the Department of the Army Breast Cancer Research Program. PAU is a Robert Wood Johnson Foundation Generalist Physician Faculty Scholar and a Senior Research Associate in Health Services Research from the Department of Veterans’ Administration.

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Armstrong, K., FitzGerald, G., Schwartz, J.S. et al. Using survival curve comparisons to inform patient decision making. J GEN INTERN MED 16, 482–485 (2001). https://doi.org/10.1046/j.1525-1497.2001.016007482.x

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  • DOI: https://doi.org/10.1046/j.1525-1497.2001.016007482.x

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