Barriers to clinical trials. Part II: Knowledge and attitudes of potential participants.

The reasons why less than 3% of cancer patients receive treatment in a clinical trial are complex and multiply determined. Because an individual cannot sign herself into a research study, an understanding of the doctor-patient interaction must be considered in addition to individual patient dynamics. Patients may be concerned that a physician's primary allegiance is to the requirements of the trial, not the specific health needs of the individual. Physicians may worry about the effects that placing an individual in a trial will have on the special doctor-patient relationship. Specific psychologic factors that may make a patient reluctant to enter a trial include self-protectiveness, time and travel constraints, concern about the quality of research versus clinical care, the nature of the informed consent, and worry about the usual low level priority assigned to quality-of-life issues in biomedical research. Enrollment in and adherence to investigative research may be served better by the construction of studies that combine questions about both medical outcome and impact of treatment on patient quality of life. Individuals who require high levels of personal control, want to feel they are a high priority with their physician, and need frequent feedback about results are not likely to be good candidates for investigative research.