In CRO, Ethnobridging, Phase 1 Clinical Trials

Volunteer Retention Strategies in Phase 1 Ethnic Bridging Clinical Trials

In this article, we’ll explore key volunteer retention strategies in Ethnic Bridging clinical trials. Effective volunteer recruitment strategies help ensure that we maintain a healthy pool of volunteers, but volunteer retention is paramount to conducting successful studies. Phase 1 volunteer retention requires even further attention, as volunteers are usually admitted to the clinical pharmacology unit (CPU) for one or more overnight treatment periods, and may need to be scheduled for completion of outpatient visits for as long as 6-12 months once releases from inpatient periods, thus strong communication on logistics become very important.


Our CPU utilizes a proprietary, IRB-approved retention program that has proven to be effective at increasing retention rates. With 100% retention rates in some cases, we’ve been able to implement a variety of different strategies to ensure volunteer compliance throughout the course of our studies. Strategies for successful patient retention include:


Study Scheduling

Share the study visit schedule with the volunteers as soon as it is finalized to minimize conflicts and allow volunteers to arrange their schedule around work, school, and family activities. The goal is ensure the highest possible compliance with all the study visits required in the protocol.

Reference Cards

Prior to the study, provide participants with reference cards that remind them of prohibited/allowed activities, including diet restrictions or other requirements that would interfere with the study results.

Study Orientation

To ensure that participants fully understand the requirements and expectations during the treatment period of the trial, check-in with volunteers at the CPU immediately preceding their dosing, reevaluating scheduling and other important factors.

Visit Schedule

At discharge from the CPU, remind volunteers of their next check-in time and provide them with a schedule to have on hand as an additional resource.

Recruitment Team

Have a dedicated recruitment team that makes phone calls and sends emails as additional reminders to participants. The team should be available for questions and assistance as needed.

Completion Bonus

With IRB approval, adjust the stipend for each visit, providing a bonus upon study completion as an incentive for volunteer retention.


Provide volunteers with access to entertainment networks and resources, including DirecTV, game consoles, Netflix, computer access, books, magazines, and free Wifi. WCCT provides a wide variety of ethnic specific entertainment and hosts events such as movie nights and English lessons for studies with long overnight confinement periods.

Ethnic Meals

If permitted by sponsors and protocol, make sure to provide participants with ethnic-specific meals during their time on site, taking special care to ensure the study does not conflict with their cultural norms.


Offer a variety of transportation options and provide travel reimbursements when necessary to allow them a safe and convenient way to get to and from scheduled study visits. This also helps ensure study visit compliance with the protocol.


The overall goal is to accommodate all participant needs as the study protocol allows, setting clear expectations with open communication, while promoting participation that does not bring about any additional financial or personal stressors to the volunteers. These volunteer retention strategies, established with our extensive experience, combine to make WCCT the premier choice for study participation in Southern California. In our next post, we’ll explore regional subject management, discussing additional factors that determine the successful completion of Ethnic Bridging clinical trials.

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