When conventional treatments are no longer effective, patients with advanced cancer may consider enrolling in early-phase clinical trials. The process of deciding on participation is often complex, and supporting patients in this process could enhance their quality of life. This multicenter prospective study explored factors contributing to decisional conflict—a reflection of decision-making quality—in patients who recently made a choice about joining phase I or I/II trials. We examined whether health-related quality of life, health literacy, hope, satisfaction with consultations, decision timing, and the decision itself were linked to decisional conflict. Among 116 patients, the average decisional conflict score was 30.0 (SD = 16.9). Regression analyses indicated that lower decisional conflict was observed in patients reporting better overall health (β = −0.185, p = 0.018), greater satisfaction with the consultation (β = −0.246, p = 0.002), and those who decided either before (β = −0.543, p < 0.001) or within a week after the consultation (β = −0.427, p < 0.001). Together, these factors explained 37% of the variation in decisional conflict. These findings suggest that patients with poorer health or who need more time to decide may benefit from additional support. While inherent patient characteristics are difficult to change, oncologists can influence satisfaction during consultations. Future research should investigate whether improving patient-centered communication can help reduce decisional conflict.
