Obstacles to the accrual of patients to clinical trials in the community setting.

Data indicate that substantial pool of candidates exists, especially in the community setting, for enrollment in clinical oncologic trials. However, only a small proportion of cancer patients are actually enrolled. Obstacles to accrual include physician determinants, patient determinants, organizational issues, and health care system factors. Physicians can influence patient enlistment in their capacity as either referring physician or study investigator. A practitioner's medical orientation may impact the likelihood of referral. Physicians reluctant to enroll patients cite logistic and practical problems and the potential for disrupting patient relationships; a trial's protocol also may be questioned. Patient refusals to participate in clinical trials may stem from practical concerns, psychosocial issues, or a wariness of toxic treatment effects. Organizational issues affecting patient accrual have not been extensively studied; an institutional review board's view of research may be a major factor. Health care system factors such as escalating costs and prohibitive reimbursement policies of third-party payers also adversely affect accrual, and will require a new commitment to minimizing protocol costs. Continued evaluation of physician and patient barriers to accrual is warranted. Once these barriers are recognized, randomized intervention trials will be required to identify ways to overcome them.