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Removing barriers to participation in clinical trials, a conceptual framework and retrospective chart review study

Norma F Kanarek12*, Marty S Kanarek3, Dare Olatoye4 and Michael A Carducci5

Author Affiliations

1 Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205, USA

2 Department of Oncology, Johns Hopkins School of Medicine, 615 North Wolfe Street, Baltimore, MD 21205, USA

3 Department of Population Health Sciences, School of Medicine and Public Health and the Nelson Institute for Environmental Studies, University of Wisconsin-Madison, 610 North Walnut Street, Madison, WI, 53726, USA

4 Johns Hopkins School of Medicine, 733 North Broadway, Baltimore, MD, 21205-2196, USA

5 Department of Oncology (Urologic Oncology), Johns Hopkins School of Medicine, Cancer Research Building I, Room 1M59, Baltimore, MA, USA

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Trials 2012, 13:237  doi:10.1186/1745-6215-13-237

Published: 10 December 2012



Enrollment in interventional therapeutic clinical trials is a small fraction of all patients who might participate given reasonable access.


A hierarchical approach is utilized in measuring staged participation from trial availability to patient enrollment. Our framework suggests that concern for justice comes in the design and eligibility criteria for clinical trials; attention to beneficence is given in the eligibility and physician triage stages. The remaining four stages rely on respect for persons. An example is given where reasons for nonparticipation or barriers to participation in prostate cancer clinical trials are examined within the framework. In addition, medical oncology patients with an initial six month consultation are tracked from one stage to the next by race using the framework to assess participation comparability.


We illustrated seven transitions from being a patient to enrollment in a clinical trial in a small study of prostate cancer cases who consulted SKCCC Medical Oncology Department in early 2010. Pilot data suggest transition probabilities as follows: 65% availability, 84% eligibility, 92% patient triage, 89% trials discussed, 45% patient interested, 63% patient consented, and 92% patient enrolled. The average transition probability was 77.7%. The average transition probability, patient-trial-fit was 50%; opportunity was 51%, and acceptance was 66.7%. Trial availability, patient interest and patient consented were three transitions that were below the average; none were statistically significant.


The framework may serve to streamline comprehensive reporting of clinical trial participation to the benefit of patients and the ethical conduct of clinical trials.

Justice; Beneficence; Respect for persons; Clinical trials; Clinical trial accrual; Prostate cancer; Barriers to clinical trials; Disparities; Framework