Tips - Recruitment & Subject Numbers

Tips & Points to Remember in the Preparation of Your IRB Recruitment Materials 

Recruitment materials should include:

  • Title of the study 
  • The PI’s name 
  • The word “research” needs to be included in your recruitment material. Make it clear to your potential study subjects that this is a research study. Participants need to know they are responding to a research study, not to a promise for free payment or treatment. 
  •  Your recruitment materials should include "Radford University."
  • A general description of the purpose of the study. Potential participants should have a basic idea of what the study entails. This information does not have to be detailed, but should explain the process in layman’s terms. Information should include what participants will do and what time will be required.  
  • Location of the research and a contact name with either a phone number or e-mail address for further information (Note: The student researcher’s phone number may not be used). 
  • Eligibility criteria, if applicable, should be noted briefly (where appropriate). This is especially helpful if payment depends on meeting these criteria. For example, “English speaking only,” “Women only,” etc. This will aid in wasting ineligible participants’ time as well as yours.  
  • State whether participants will be paid for their time and effort. 


  •  “You will be compensated for your participation.”  
  • “You will receive a gift card to X for [amt.] for your participation.” 
  • “Participants will be compensated.”                 


  • EARN $200! Get FREE pizza for the semester!
  • Any payment incentives may be included but should not be the most prominent element on the page such as the use of larger or bold type. Compensation should not be excessive considering the nature of the project.  Payment should be stated as a range of amounts or stated as “at least” or “up to” for payments dependent on the amount of participation.

Elements That Are Not Allowed:

  • Offers of compensation from the sponsor that would involve a coupon good for a discount on the purchase price of the product once it has been approved for marketing. 
  • Claims that state or imply a certainty of a favorable outcome or other benefits beyond what is outlined in the consent document or protocol. 
  • Claims that drub, biologic, or device is safe or effective for the purpose of investigation. 
  • Claims, either explicitly or implied, about the drug, biologic, or device under investigation that is inconsistent with FDA labeling. 
  • Use of the term "new treatment", "new medication", or "new drug" in reference to a drug or device without explaining that the test article is investigational. 
  • Use of the term "free" in reference to treatment or procedures. 
  • Use of exculpatory language (language in the advertising whereby prospective study participants waive or appear to waive any of their legal rights). 
  • Use of bold or enlarged print or other means to emphasize payment or the amount to be paid. 

Tips for recruitment materials:

  • Avoid phrases such as "help needed" or "subjects wanted." 
  • Examples of recommended wording include "You are invited" or "Participants invited."  
  • Recruitment in classrooms: Potential participation in research must be presented as a voluntary option and cannot be tied to grades. It must be clear that there will be no stigmatization of students who decline to participate. If class time will be taken for research participation, alternate activities should be provided for those who decline. 

Subject Population Size and Over-Enrollment

Radford University requires that applications for human subjects research specify the number of participants to be enrolled in the research study. The Radford IRB requires the submission of a modification or amendment to increase the approved sample size of the proposal. 

When the approval is issued, approval is granted to enroll only the number of participants listed in the application.  Your IRB approval letter will state the number of study subjects are approved to be enrolled. 

The number of study subjects approved is the number of participants who enroll in the project and NOT the number of subjects with usable data for analysis.

Once this number is reached, enrollment must cease. A modification/amendment must be submitted to the IRB to increase subject numbers.  

In cases where researchers enroll more subjects than the number approved, data from the over-enrolled subjects must be discarded.  Keep in mind, the IRB does not give retroactive approval for those subjects who have already been enrolled over the approved number. 

To reduce the likelihood of over-enrolling subjects, you are encouraged to monitor carefully, the number of subjects recruited and be prepared to amend your protocols to increase sample size before the maximum approved subject number has been reached. 

Example: Enrolled number of subjects past the approved number - The IRB protocol was approved for enrollment of 150 study participants and 175 participants were enrolled. Data collected for study subjects 151 through 175 may not be used. 

Tip: For research studies using Qualtrics for surveys: Remember to set enrollment limits in the parameters of your study.