Co-enrollment of Patients in Research Involving Tissue Collection

Co-enrollment is the concurrent involvement of an individual participant in two or more research studies.¹ Generally, co-enrollment is not allowed in clinical trials of drugs and medical devices because of concerns about safety and scientific integrity.² However, in many parts of the world, there is no consensus about co-enrollment outside the context of clinical trials, such as in research involving tissue collection.

A research assistant in the obstetrics and gynecology department of a Southeast Asian hospital plans to recruit and obtain consent from patients for several preclinical studies that require collection of tissue samples. The research assistant approaches women who are waiting in the hospital for consultation, screening, or procedures or when they are admitted for delivery or surgery. Tissue samples from patients who agree to participate in research are usually collected during or after a procedure (e.g., biopsy, amniocentesis, placental delivery) as coordinated with the clinicians or during their scheduled clinic appointments (e.g., blood, urine).

To enroll as many participants as possible, the research assistant requests patients who meet all inclusion criteria to participate in more than one research study. The research assistant discusses the risk and benefits of each separate research study with patients individually, explaining that participation is voluntary and that they are free to withdraw from the study at any time with no impact on their care. Patients are given the opportunity to think and ask questions before they agree to participate in the research and provide written consent.

The principal investigator of one of the studies raises a concern about individuals participating in more than one study, after learning there are a number of patients who have co-enrolled. Concerned about burdening patients with multiple sample collections, the researcher refuses to allow research participants to co-enroll in other studies. Most of the research studies recruiting participants from this hospital do not offer financial incentives to patients, but some share the routine laboratory results with patients enrolled in research. Although the studies do not directly benefit the patient-participants, future benefits for the field of women’s health are possible.