Shared models of patient-physician decision making have been shown to be commonly preferred in standard treatment decisions. In the decision to join a cancer clinical trial however, autonomous decision making is emphasized in research ethics. Few studies have explored factors that influence this decision or satisfaction with this decision. Greater understanding of how patients decide to join a cancer trial could allow clinicians to support patient and family values surrounding this decision. Therefore, the aims of this study were: (1) to examine the relationship between disease context (cancer stage, symptom burden) and sociodemographic factors (age, educational level, race, sex) to patient preferences for research decision control and (2) to identify significant factors (i.e., disease context and sociodemographic factors, patients preferences for research decision control, hope, quality of life, trust, understanding risks, and adequacy of research information) that influence the decision to join a clinical trial and satisfaction with this decision.

A descriptive, cross-sectional research design with a mailed survey data collection method described factors related to the decision making process regarding participation in a cancer clinical trial and satisfaction with this decision. Self-report and medical record reviews provided data for this study. The sample consisted of 197 patients with advanced gastrointestinal cancer. Multiple logistic regression analysis was used to examine factors that influence cancer clinical trial participation and satisfaction with this decision.

Although the selected variables examined explained only a small portion of variance in predicting participation and satisfaction with the decision to join a cancer trial, a great majority of patients reported a shared decision making style as the preferred method of deciding to join a cancer trial (83%). In spite of the discordance between the participants' preference for shared decision making and regulatory processes in research promoting autonomous decision making, participants were very satisfied with their decision.

Enhancing a shared style of research decision making may facilitate an increase in cancer clinical trial enrollment rates. Health care providers have unique opportunities as educators and researchers to support shared decision making by those who prefer this method in deciding whether to join a cancer trial.