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Perceptions of control and unrealistic optimism in early-phase cancer trials
  1. Lynn A Jansen1,
  2. Daruka Mahadevan2,
  3. Paul S Appelbaum3,
  4. William M P Klein4,
  5. Neil D Weinstein5,
  6. Motomi Mori6,
  7. Catherine Degnin7,
  8. Daniel P Sulmasy8
  1. 1Madeline Brill Nelson Chair in Ethics Education, Oregon Health & Science University, Center for Ethics in Health Care, Portland, Oregon, USA
  2. 2Arizona Cancer Center, University of Arizona, Tucson, Arizona, USA
  3. 3Department of Psychiatry-Columbia, University College of Physicians and Surgeons, Columbia, South Carolina, USA
  4. 4Behavioral Research Program, National Institutes of Health/National Cancer Institute, Bethesda, Maryland, USA
  5. 5Department of Human Ecology, Rutgers University, New Brunswick, New Jersey, USA
  6. 6Departments of Public Health and Preventive Medicine and Medical Informatics and Clinical Epidemiology, Oregon Health & Science University/Knight Cancer Institute, Portland, Oregon, USA
  7. 7Oregon Health & Science University, Portland, Oregon, USA
  8. 8Departments of Medicine and Philosophy, Georgetown University, Georgetown, Washington DC, USA
  1. Correspondence to Dr Lynn A Jansen, Madeline Brill Nelson Chair in Ethics Education, Oregon Health & Science University-Center for Ethics in Health Care, 3181 S.W. Sam Jackson Park Rd, Portland, OR 97239, USA; jansen{at}


Purpose Recent research has found unrealistic optimism (UO) among patient-subjects in early-phase oncology trials. Our aim was to investigate the cognitive and motivational factors that evoke this bias in this context. We expected perceptions of control to be a strong correlate of unrealistic optimism.

Methods A study of patient-subjects enrolled in early-phase oncology trials was conducted at two sites in the USA. Respondents completed questionnaires designed to assess unrealistic optimism and several risk attribute variables that have been found to evoke the bias in other contexts.

Results One hundred and seventy-one patient-subjects agreed to be interviewed for our study. Significant levels of perceived controllability were found with respect to all nine research-related questions. Perceptions of control were found to predict unrealistic optimism. Two other risk attribute variables, awareness of indicators (p=0.024) and mental image (p=0.022), were correlated with unrealistic optimism. However, in multivariate regression analysis, awareness and mental image dropped out of the model and perceived controllability was the only factor independently associated with unrealistic optimism (p<0.0001).

Conclusion Patient-subjects reported that they can, at least partially, control the benefits they receive from participating in an early-phase oncology trial. This sense of control may underlie unrealistic optimism about benefiting personally from trial participation. Effective interventions to counteract unrealistic optimism may need to address the psychological factors that give rise to distorted risk/benefit processing.

  • early phase cancer trials
  • informed consent
  • unrealistic optimism
  • perceived control
  • research ethics
  • decision making

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  • Funding Work on this study was funded by NIH/NCI grant RO1CA166556.

  • Competing interests None decalred.

  • Ethics approval Institutional Review Boards at OHSU and University of Tennessee.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data sharing statement There are no additional unpublished data.