Site enrollment

Enrollment strategies for principal investigators

By TrialNotice · Updated
Principal investigator with a gray beard walking down a research clinic corridor with a coordinator in teal scrubs
Short answerPrincipal investigators lift enrollment by owning the patient sources only a physician can open: their own patient panel, relationships with referring colleagues, and the clinical credibility that makes community doctors trust a study. The strategies that move numbers are reviewing protocols for enrollment risk before signing, personally reaching referring physicians, and holding a weekly funnel review with coordinators.

Why does the PI matter so much for enrollment?

Because many of the strongest recruitment levers are physician to physician. Investigator turnover is also high: a Duke and FDA survey classified 54.2% of investigators as one and done, and almost half of those wanted to do more trials but lacked opportunities (DaVita Clinical Research). PIs who enroll well are the ones sponsors return to.

Strategy one: review protocols before you sign

Map the deciding criteria to your patients and referral sources before committing. See how to review a protocol for enrollment risk.

Strategy two: work your own panel

Under HIPAA's preparatory to research provision, researchers within a covered entity can review records to identify potential participants (University of Wisconsin). Confirm your IRB's process, then make chart review a scheduled task, not an afterthought.

Strategy three: reach referring colleagues personally

A letter signed by the PI carries clinical credibility a vendor cannot. FDA guidance treats doctor to doctor letters as outside direct advertising review (FDA), though your IRB may set its own rules. Physicians say they skip referrals mainly for lack of study information and time (Tufts CSDD), so keep it to one page.

Strategy four: close the loop yourself

Nearly 30% of physicians never hear back after referring (Tufts CSDD). A short note or call from the PI after a referral is one of the strongest relationship builders available.

Strategy five: run a weekly funnel review

Fifteen minutes with coordinators: candidates identified, screened, randomized, and the top screen failure reasons. With average screen failure at 36.3%, and 57% in CNS trials (Tufts CSDD), catching a recurring failure reason early saves weeks.

Strategy six: delegate the system, not the relationships

Coordinators and outreach partners can run lists, mailings, tracking, and follow up. The PI's time is best spent on the personal touches: signatures, calls to key referrers, and visible commitment to the study.

Related: how coordinators get referrals from community doctors.

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. DaVita Clinical Research, summary of the Duke and FDA investigator survey (Contemporary Clinical Trials Communications, 2017)
  2. MedCity News, "Is clinical trial design complexity behind the high turnover rate for principal investigators?"
  3. University of Wisconsin Madison, HIPAA for Researchers FAQ
  4. FDA, "Recruiting Study Subjects" guidance for IRBs and clinical investigators
  5. Applied Clinical Trials, "Tufts CSDD Study Explores Low Recruitment Rates"
  6. Applied Clinical Trials, "Can Recruitment and Retention Get Any Worse?" (Tufts CSDD screen failure study)

Keep reading

Research site manager looking at a monitor showing an enrollment bar chart falling below a red target line
Site enrollment

Why clinical trial sites miss enrollment targets

Tufts CSDD found 11% of sites enroll zero patients and 37% under enroll. Here is what the data says about why sites fall short and what a site can control to fix it.

 Two research site staff members arranging sticky notes on a weekly planning whiteboard
Site enrollment

Behind on enrollment: a recovery plan for clinical research sites

If your site is behind on enrollment, you are not alone: 37% of sites under enroll. Here is a four step recovery plan: diagnose the funnel, re mine records, add a physician referral source, and report weekly.

 Principal investigator pointing at a whiteboard of sticky notes while a sponsor manager looks on in an office at dusk
Site enrollment

How sponsors can rescue an underperforming clinical trial site

With 37% of sites under enrolling and 11% enrolling no one, sponsors face the rescue decision often. Here are the options, from site support and physician outreach funding to protocol changes.