Direct answer: To recruit patients for a clinical trial, sites need a realistic population plan, approved participant-facing materials, clear lead ownership, prompt and respectful contact, a documented pre-screening handoff, qualified clinical screening and practical support through the first visit. The workflow should be designed with the sponsor and CRO, then measured by stage rather than judged only by total enrolment.
Before activation: build a recruitment reality check
Recruitment performance is constrained long before a campaign launches. Compare the eligibility criteria with the site’s actual patient pathway, competing studies, appointment capacity and referral relationships. The HRA advises teams to consider whether proposed sites can identify the required population or need other organisations to help identify potential participants.
- Estimate the reachable population using evidence the site can explain.
- Identify criteria that require records, tests or investigator judgement.
- Map which sources may be used and what permission exists for contact.
- Confirm who can answer study questions and when.
- Reserve screening and visit capacity before increasing lead volume.
The seven-step site playbook
- Choose the population, then the channel.
Start from where potentially eligible people receive care and information. A channel is useful only if it reaches the intended population ethically and produces a manageable next step.
- Use current, approved materials.
Participant-facing messages should match the approved study information. Keep version ownership explicit across adverts, scripts, landing pages and referral packs.
- Assign every lead.
Set an owner, service window, permitted contact method and escalation rule. Avoid promising a universal response-time figure; choose one the study can staff and monitor.
- Explain before you question.
Identify the study context, explain why the person is being contacted and distinguish preliminary questions from formal screening. Make it easy to decline.
- Structure the pre-screen.
Use only approved questions, preserve uncertainty and record enough context for a human reviewer. Do not turn an automated score into a clinical conclusion.
- Close the handoff.
Define who reviews responses, how the outcome is recorded, who contacts the person and what happens if more information is needed.
- Support the first visit.
Give clear logistics and a reliable contact route. Recruitment is not complete if a qualified person cannot navigate the next step.
Measure the funnel without rewarding the wrong behaviour
| Stage | Useful measure | Diagnostic question |
|---|---|---|
| Lead received | Volume by approved source | Are sources reaching the intended population? |
| Contact | Contact rate and time to first attempt | Is capacity matched to incoming demand? |
| Pre-screen | Completion and review-ready rate | Are questions clear and is uncertainty preserved? |
| Site review | Review turnaround and next-action rate | Does every record leave the queue with an owner? |
| Visit | Booked-to-attended rate | Which practical barriers remain? |
| Formal screening | Screen failure by reason | Can feasibility or early questions be improved lawfully? |
Compare rates by site and source, but interpret them with context. A higher pre-screen pass rate is not automatically better if it comes from narrowing access unfairly or hiding uncertainty.
Make participant information usable, not merely complete
Good recruitment copy helps a person decide whether to learn more; it should not pressure them. HRA quality standards call for a study-specific summary, an explanation of why the person is invited, what participation involves, duration, activities, risks and benefits, the voluntary nature of participation and clear contact routes. Those standards are UK-specific, but the underlying discipline is widely useful.
Test materials with the people they are meant to serve. Plain language, accessible formats and appropriate localisation should be planned, not added after recruitment stalls.
What this means for sponsors, CROs and sites
Sponsors
Fund the whole pathway, including site review and appointment capacity. Approve a measurement plan alongside the materials.
CROs
Monitor handoffs and version control, not only aggregate enrolment. Escalate recurring operational friction.
Sites
Own the local reality: population, staff availability, referral routes and the qualified review of every potential match.
Using Nacar in the playbook
Nacar can support approved patient contact and pre-screening questions, then structure responses for the study team to review. The team decides eligibility and who advances. A demo should therefore start with the study’s responsibility map and approved workflow—not with a claim that software replaces clinical screening.
Frequently asked questions
What is the most effective patient recruitment channel?
There is no universal winner. The best mix depends on the study population, local care pathway, approved use of data, site capacity and the barriers faced by potential participants.
How quickly should a site contact a new lead?
Set a study-specific service window that the site can staff and monitor. Faster contact may reduce avoidable loss, but speed must not override permissions, approved messaging or respectful communication.
Should a site pre-screen by phone?
Phone can be appropriate when it is approved for the study and accessible to the population. The call should use approved questions, explain its preliminary nature and route responses to qualified site review.
Which recruitment metric matters most?
No single metric is sufficient. Use a connected funnel from lead source through contact, pre-screen, site review, visit, formal screening and enrolment so that improvement in one stage does not hide failure in another.
Does Nacar decide which patients qualify?
No. Nacar structures responses gathered through approved questions. The study team reviews the information and makes the clinical eligibility decision.
Primary sources
By
Pedro Torrecillas
Founder & CEO, Nacar.ai
Pedro has spent more than a decade building recruitment companies and products. At Nacar, he applies that operating experience to clinical-trial patient recruitment.
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