Barriers to clinical trials. Part III: Knowledge and attitudes of health care providers.

The role of clinical trials is becoming extremely important for our understanding of the effects of different therapeutic modalities of cancer treatment and the value of their interactions. Participation of patients in clinical trials remains disappointingly low, with less than 3% of the estimated 1.17 million patients with newly diagnosed cancers entering the studies. Several physician-based factors hinder accrual of patients--(1) lack of awareness of or access to clinical trials, (2) physician bias that the trial therapy is not as good as the "standard therapy" even though the standard therapy may provide a response rate of less than 20%, (3) physician's concern about losing patients to follow-up, (4) the complexity of the clinical trial(s), which requires excessive amount of time to discuss, implement, and follow-up the patient, (5) the lack of equitable compensation for the physician's time and effort, and (6) excessive costs of laboratory and radiologic tests that are not paid by the agency or group sponsoring the study, particularly in Phase I and II trials. These factors are confounded by the lack of institutional review boards in several community hospitals, associated with a complex and lengthy procedure to institute such a board. The article presents recent surveys dealing with attitudes and practices of health care providers toward clinical trials. The National Cancer Institute, the American Cancer Society, and other societies, groups, and agencies, including the health insurance industry, should continue to encourage and support clinical trials.