Why Is Recruiting Participants For Research So Difficult?

13 November 2020



An adequately powered study is integral to the success of research projects. Many research studies encounter difficulties with recruiting participants. Approximately 80% of clinical trials are delayed or cancelled due to recruitment difficulties.


Exploring the factors contributing to recruitment difficulties can help us to select effective strategies for increasing the intake of participants for research studies. Here we explore three main barriers contributing to difficulties recruiting participants in research trials. 


Barrier #1: Centre-related barriers


It is undeniable that recruitment requires a lot of dedicated time and resource. Research centres or university institutions with limited personnel to dedicate time and resources in recruitment can impact on studies achieving the required sample size. For some research, limited funding to offer sufficient rewards or incentives may influence participants' decision to participate in the study. 


At RecruitKoala, we are committed to helping you overcome some of the barriers researchers may face during recruitment. To discuss how RecruitKoala can support you, please contact at hello@recruitkoala.com.


Barrier #2: Participant-related barriers


One of the most common participant-related barriers is due to fear and mistrust. Participants may be fearful of the side effects of the treatment. Some participants, especially those from socially disadvantaged groups may experience fear of authority due to previous prejudice in their community. They might feel that their participation could cause potential harm to their community. 


Other potential participant related barriers may include language difficulties or limited understanding of the research procedures. For example, some participants may have misconceptions about randomisation procedures in clinical trials. Additionally, hard to read research information can also be a barrier to recruitment. 


Barrier #3: Study-related barriers


Studies highlighted narrow eligibility criteria can potentially be a barrier to recruiting a larger number of participants. Complex screening procedures may result in lower participant registration. It is also essential to have a clear and organised research process.  Unclear or limited study information may also discourage some participants from expressing their interest in the study.