Comparisons

Physician referrals vs Facebook ads for clinical trial recruitment

By TrialNotice · Updated
Clinical research coordinator comparing a social media feed on her phone with a printed physician referral letter
Short answerOnline ads tend to produce enrollees faster and at lower cost per enrollee, while offline channels, a group that includes physician referrals, tend to convert a larger share of the people they reach. A meta analysis found online recruitment cost $72 per enrollee versus $199 offline, yet 69% of studies comparing conversion found offline methods did better. Most sites need both.

What does head to head research show?

A systematic review and meta analysis compared online and offline recruitment across published studies. Online recruitment was more effective per active day of recruiting and cost less per enrollee, $72 versus $199. But 69% of the studies that compared conversion found offline methods converted better (JMIR).

The meta analysis compares online methods with offline methods as a group. Physician referral is one offline channel, so treat these as directional, not a direct referral versus Facebook test.

Where do patients say they learn about trials?

In CISCRP's 2025 study, people who had participated in a trial most often found out about it online (22%) or from their own doctor (16%). Among people who prefer to hear about studies online, social media was the top choice, with Facebook named most often (Citeline summary of CISCRP 2025). Yet in CISCRP's 2017 study, 58% said they would begin a trial search by asking their doctor (CISCRP).

Where do Facebook ads win?

  • Speed and volume. Campaigns can launch quickly and reach many people who self identify with a condition.
  • Lower cost per enrollee in the published comparisons.
  • Reaching people not in active care, who may never see a specialist.

Where do physician referrals win?

  • Established diagnosis. The physician already manages the condition.
  • Trust. Most people would ask their doctor first.
  • Conversion. Offline methods converted better in most comparisons, which matters because screening is costly: in one 25 practice trial, sites screened 7.2 patients for each one randomized on average (PMC).

How should a site use both?

  1. Run ads for volume and physician outreach for prequalified patients.
  2. Track every patient's source through randomization.
  3. Compare channels on cost per randomized patient and ROI, not cost per lead.

See how to calculate recruitment ROI and what it costs to recruit one patient.

Get your study in front of the right local physicians

TrialNotice builds a physician referral pipeline around one active study. We identify relevant local physicians within driving distance of your site, send study aligned direct mail, follow up by email and LinkedIn, track engagement with recipient level QR codes, and route warm responses into your site team's workflow.

Talk to TrialNotice

Sources

  1. Brøgger Mikkelsen M. et al., "Online Patient Recruitment in Clinical Trials: Systematic Review and Meta Analysis," Journal of Medical Internet Research
  2. Citeline, Patient Recruitment Pulse (Jan 2026) on the CISCRP 2025 Perceptions and Insights Study
  3. CISCRP, 2017 Perceptions and Insights Study: Decision Making Process
  4. "Site specific factors associated with clinical trial recruitment efficiency in general practice settings," PMC

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