Context: Patients with acute life-threatening illness are candidates for enrollment in multiple trials. Whether patients are enrolled in multiple trials has implications for patient safety, trial enrollment duration, and study validity.
Objective: We review issues related to coenrollment and propose guidelines for when it should be allowed.
Results: There is no regulatory prohibition on coenrollment of patients in more than one study. Randomized trials of interventions for a variety of clinical conditions have allowed coenrollment without any reported deleterious impact on either study. Guidelines for coenrollment are proposed.