3 Critical Barriers to Recruiting for Research
Why enrollment falls short — and what research teams can do about it.
Enrollment timelines slip. Budgets stretch. Studies that could help patients sit idle while teams scramble to find the right participants. If you work in clinical research, this story is probably familiar.
Recruiting for research is rarely as straightforward as posting a flyer or running a single ad. The gap between a study opening and a study fully enrolled is almost always wider than anticipated — and it tends to widen for predictable reasons. Knowing those reasons gives you a real shot at closing the gap.
Here are three barriers that come up again and again, and what it looks like when teams start working through them.
1. Reaching People Who Don't Know the Study Exists
The most qualified potential participant in the world can't enroll if they never hear about the study. Yet many recruitment efforts rely heavily on a single channel — a posting on a registry, word of mouth from a referring physician, or flyers in a clinic waiting room.
The reality is that different people find information in different places. Some rely on their doctor. Others search online after a diagnosis. Many are active in community groups, faith organizations, or disease advocacy networks. A recruitment strategy that only covers one or two of those touchpoints will always leave a portion of the eligible population unreached.
Digital advertising has changed what's possible here. Targeted outreach — when done thoughtfully and in line with ethical guidelines — can connect studies with people who are actively looking for options but have no idea a relevant trial is open near them. Community outreach, including partnerships with organizations that already have trust in a given population, adds another layer that digital alone can't replicate.
The question for any team recruiting for research is: are we showing up where our participants actually are, or just where it's convenient for us to post?
2. Screening Processes That Lose People Before They Enroll
Getting someone interested is only part of the job. What happens next — how quickly they're contacted, how clearly the process is explained, how easy it is to ask questions — determines whether interest turns into a signed consent form.
Long gaps between a referral and a first contact, confusing eligibility questionnaires, and unclear next steps are among the most common reasons interested candidates quietly disappear. From the participant's perspective, a slow or confusing process can feel like a signal that their time isn't valued, or that the study isn't well organized.
This is an area where process design matters as much as outreach volume. A site that responds quickly, communicates clearly, and guides potential participants through each step will convert a higher proportion of inquiries into enrolled participants — without needing to generate more leads at the top of the funnel.
For study coordinators specifically, this often means looking honestly at where candidates are dropping off and asking what a better experience at that stage would look like.
3. Underestimating How Long Recruitment Actually Takes
Planning assumptions about enrollment timelines are frequently optimistic. A study that projects six months to full enrollment may find itself at month nine with less than half the target reached. This isn't a failure of effort — it often reflects the difficulty of translating a protocol's eligibility criteria into a realistic estimate of how many people in a given area will qualify, be reachable, and agree to participate.
Enrollment planning that accounts for real-world screening failure rates, seasonal slowdowns, site-specific referral patterns, and the time needed to build community awareness tends to produce more accurate projections. It also tends to surface the need for additional recruitment support earlier — before a timeline is already in trouble.
For sponsors and CROs, building a more honest picture of recruitment timelines at the design stage can prevent the downstream pressure that forces reactive decisions later. For research sites, it means having an honest conversation with sponsors about what's achievable with current resources.
Building a Strategy That Addresses All Three
None of these barriers is insurmountable. The teams that navigate them most effectively tend to share a few traits: they diversify their outreach channels, they pay close attention to the participant experience throughout the screening process, and they build recruitment timelines based on realistic assumptions rather than optimistic ones.
Recruiting for research is genuinely hard work, but it's also work that benefits from the right partners, tools, and planning.
If your team is working through any of these challenges, CliniContact helps research sites, sponsors, and CROs find, screen, and enroll the right participants using digital advertising, community outreach, and a purpose-built platform.
