Participant Retention and Tracking


Once you have started to recruit participants, it is important for you to continue to engage them in your project and to track your enrollment progress. These are tips and resources to help you retain and track participants.

Retention Ideas

Recruitment and retention of volunteers is crucial to the success of clinical research studies. Recruitment and retention start on day one of your study. Nearly 80 percent of clinical research sites fail to finish on time. This is largely due to challenges related to recruitment and retention. Below are several ideas for recruiting and retaining study volunteers.

The most important point to remember is study teams are building relationships with volunteers. Motivators for why volunteers participate will vary from volunteer to volunteer, and it is an important to know why your participant decided to volunteer for your study, so ask them. Once you know what motivates a volunteer, you can make it a point to remember. Reinforce it throughout your interactions with them. The most important thing you can do is elevate the status of your volunteer. What you need to reinforce with your volunteers is that without them, medical breakthroughs would not be possible.

Don’t forget that your current volunteers could serve as helpful communicators about your study to other potential volunteers. Some options to engage them include:

Try to have in-person conversations 

  • Face-to-face communication is best when talking to volunteers.

Be timely

  • Return volunteer phone calls as soon as you are able. If you are overwhelmed with requests, change your voicemail to say it may take 7-10 business days to respond to requests.
  • Return messages on UMHealthResearch as soon as you can. If you are overwhelmed with requests, use our templates to create a message saying that it may take 7-10 business days.
    • You can temporarily deactivate your UMHealthResearch study and reactivate later.
    • If you are out of the office and no other staff members are able to handle UMHealthResearch messages, you can also create a message that says all emails/phone calls will be returned once you are back.
    • If your study has reached their numbers and you are still receiving emails, be sure to send a request back to the volunteers thanking them for their interest.

Remember things about them

  • Use volunteer files to write notes about each visit. While talking with the volunteer, ask questions that you’ll be able to follow up on. For example, ask them if they are planning to go on vacation this year; if that happens to fall within your study timeline, ask them about it.

Be flexible

  • Consider evening or weekend hours to accommodate study participants. Stay after hours one day a week to catch up on phone calls if needed.

Thank-you card

  • These letters can be sent through email or direct mail and can be sent during the study process or after the study is completed

Birthday card

  • These can be sent by study staff.

Appreciation item or thank-you item

  • Items include tchotchkes or trinkets that have your department logo on it.
    • Be sure to include this in the IRB to ensure it is not considered coercive.

Travel and meal vouchers

  • A note on compensation: It is important to consider all of these items when planning for compensation.
    • Parking
    • Child care
    • Travel to Ann Arbor or clinical research location
    • Transportation

Patient reminder service

  • Ask patients how they would like to be reminded of their appointments.
    • Phone call
    • Email
    • Text message
    • When communicating with volunteers, remember to give them the following information:
      • Your name
      • Your contact information
      • Directions to your clinical research location

Other Ideas

  • Host an event to thank them for their participation and inform them of study progress.
  • Include an easy way for current volunteers to forward or share study information to their friends/family who might be interested. Examples: postcards, brochures, web link within email
  • Hosting an event that is open to the public to provide education about the specific condition of interest and current research/therapies to the community (for example, a talk at the Ann Arbor District Library)

Staying on Target – Recruitment Tracking

How do you know if you are on track to recruit and enroll all of the participants required for your study? You first need to know your enrollment target, and then calculate how many volunteers you need to recruit each month to stay on track to successfully enroll that targeted number of volunteers. Create a tracking log where you track each volunteer you contact, screen and enroll. This will help you to identify whether you are on track or behind with volunteer recruitment. Staying on top of your recruitment analytics is crucial to determine whether you will reach your enrollment goals by your deadline.

Please visit the Study and Data Management section for templates to organize and maintain your study documentation.


If you have questions about the guidance provided on this page, contact the MICHR Participant Recruitment Program at

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