["Here we report the results of a randomized study undertaken to test the efficacy of a supplementary, telephone-based nursing intervention in increasing patients' awareness and understanding of the clinical trials in which they are asked to participate.", 'During a 12-month period, 180 cancer patients who were approached to participate in a phase II or III clinical trial were randomized to undergo either of the following: (1) standard informed consent procedures based on verbal explanations from the treating physician plus written information (controls); or (2) standard informed consent procedures plus a supplementary, telephone-based contact with an oncology nurse (intervention). For purposes of evaluation, face-to-face interviews were conducted with all patients approximately 1 week after the informed consent process had been completed.', "The two groups were comparable with regard to sociodemographic and clinical variables. Both groups had a high level of awareness of the diagnosis and of the nature and objectives of the proposed treatments. The intervention group was significantly (P < .01) better informed about the following: (1) the risks and side effects of treatment; (2) the clinical trial context of the treatment; (3) the objectives of the clinical trial; (4) where relevant, the use of randomization in allocating treatment; (5) the availability of alternative treatments; (6) the voluntary nature of participation; and (7) the right to withdraw from the clinical trial. The intervention did not have any significant effect on patients' anxiety levels or on rates of clinical trial participation. Patients reported high levels of satisfaction with the intervention."] Does telephone-based nursing intervention improve the effectiveness of the informed consent process in cancer clinical trials?