Why are (or are not) patients given the option to enter clinical trials?

Much attention has been paid to the use of ethical principles to guide the conduct of clinical trials. Less has been done to clarify and assess the "weights" assigned by clinicians (and others) to the values that come into conflict when patients are offered entry into trials. Quantitative techniques of value assessment were used to measure the relative importance of variables frequently identified as barriers to the entry of patients into clinical trials. Responses were obtained from 52 oncologists, 26 clinical trials and senior nurses, and 23 family physicians. The group of oncologists identified the scientific design of the trial as the most important factor. In contrast, the groups of nurses and family physicians gave higher weight to effects of the trial on the doctor-patient relationship. The results illustrate ways in which methods of value assessment may be used to clarify and rank values.