Understanding of an aggregate probability statement by patients who are offered participation in Phase I clinical trials

Authors

  • Kevin P. Weinfurt Ph.D.,

    Corresponding author
    1. Center for Clinical and Genetic Economics, Duke Clinical Research Institute, Duke University Medical Center, Durham, North Carolina
    • Center for Clinical and Genetic Economics, Duke Clinical Research Institute, P.O. Box 17969, Durham, NC 27715
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    • Fax: (919) 668-7124

  • Venita DePuy M.Stat.,

    1. Center for Clinical and Genetic Economics, Duke Clinical Research Institute, Duke University Medical Center, Durham, North Carolina
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  • Liana D. Castel M.S.P.H.,

    1. Center for Clinical and Genetic Economics, Duke Clinical Research Institute, Duke University Medical Center, Durham, North Carolina
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  • Daniel P. Sulmasy O.F.M., M.D., Ph.D.,

    1. John J. Conley Department of Ethics, St. Vincent's Manhattan, Saint Vincent Catholic Medical Centers, New York City, New York
    2. Bioethics Institute of New York Medical College, Valhalla, New York
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  • Kevin A. Schulman M.D.,

    1. Center for Clinical and Genetic Economics, Duke Clinical Research Institute, Duke University Medical Center, Durham, North Carolina
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  • Neal J. Meropol M.D.

    1. Divisions of Population Science and Medical Science, Fox Chase Cancer Center, Philadelphia, Pennsylvania
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Abstract

BACKGROUND

There is concern that patients with poor numeracy may have difficulty understanding the information necessary to make informed treatment decisions. The authors sought to characterize a special form of numeracy among patients with advanced cancer who were offered participation in Phase I oncology clinical trials.

METHODS

Surveys were administered to 328 cancer patients who were considering Phase I trials. Their frequency-type numeracy was assessed using a multiple-choice question involving a hypothetical scenario in which a physician stated that an experimental treatment would control cancer in “40% of cases like yours.” In univariate and multivariable analyses, patient characteristics that were associated with better numeracy were identified.

RESULTS

The correct frequency-type interpretation was selected by 72% of respondents. Fourteen percent of respondents incorrectly selected a belief-type answer, “The doctor is 40% confident that the treatment will control my cancer.” In a multivariable model, patients who answered incorrectly tended to have less formal education and less experience with experimental therapies.

CONCLUSIONS

Because the misunderstandings some patients demonstrated may influence their treatment decision making adversely, it is critical to identify such patients and to give them special consideration when communicating information about potential risks and benefits of treatment. Cancer 2004. © 2004 American Cancer Society.

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