Accrual to cancer clinical trials: directions from the research literature.

Although randomized clinical trials are the predominant method used to evaluate cancer therapies, only a small proportion of potential participants actually enter onto trials. This paper analyzes the research literature on accrual to cancer therapy trials. The research shows that nonparticipation is influenced by physician and patient variables, as well as by characteristics of the specific protocols. Trials design, especially pre-existing treatment preferences, pose significant problems for physicians and patients. Intervention strategies have focused on alternate trial designs, improving the informed consent process, and increasing knowledge about trials. Additional research should focus on the perspectives of patients who accept and decline trial participation and on interventions designed to affect accrual. Future studies need to be sensitive to patient quality of life considerations as well as practical and ethical issues.