Methods of Recruitment
Recruitment methods impact the enrollment of a representative sample as well as the types of participants entered into a trial, which in turn impacts study outcomes and the generalizability of the findings and the translation of the intervention into practice. However, investigators often place a low priority on comparing different recruitment methods (Huynh et al., 2014). As a result, there is little understanding of the key barriers and facilitators for specific populations or what the driving issues are regarding recruitment and retention as they relate to intervention research. Investment of time and resources to learn what methods may work in distinct communities to improve community acceptance of clinical research and thus improve participation is important (George et al., 2014; Morrison, Winter, & Gitlin, 2014).
Recruitment strategies can be broadly classified into the following categories: medical referral, community outreach, mass media, direct contact, personal referral, incentives, and registries (Huynh et al., 2014). Medical referral is health professionals inviting participants to the study. Community outreach involves mobilizing the community to promote the study at local fairs, churches, or community-organized events. Mass media refers to using public service announcements and advertisements to inform potential participants about the study. Direct contact involves mailing, telephoning, or e-mailing potential participants. Personal referral includes word-of-mouth referral by friends and family to the study. Incentives include cash or prizes to compensate for the participants’ time in the study. Finally, registries refer to the use of clinical databases (e.g., electronic medical records) to identify potential participants for the study. Given that the recruitment process is expensive, and time and labor intensive, it is essential that researchers know how to effectively and efficiently use each of these strategies and identify what works best for the targeted community/population. For example, for studies involving family caregivers, speaking at support groups can be effective as well as working with organizations that serve older adults such as the Alzheimer’s Association or Easter Seals. African Americans tend to respond to outreach activities through churches, whereas Hispanics tend to respond more to radio advertisements or community outreach. Recently, technology has also opened up new venues for participant recruitment. Given that individuals are increasingly using the Internet for health information and forms of social support, researchers are in turn using Internet communities as recruitment sites for research participants. There are both free and paid (e.g., browsers search ads) online recruitment methods. Clearly, one of the advantages of this approach is the potential to reach larger numbers of participants. However, a challenge is that certain segments of the target population may not have access to the Internet such as those in the older cohorts or of low SES.
Generally, recruitment approaches that involve a variety of methods and active approaches (e.g., outreach talks) tend to be more beneficial than passive approaches (e.g., flyers). Given the expense and effort associated with recruitment, it is important to track which methods provide the most yield with respect to participant enrollment.