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5 Phase I Participant Recruitment Best Practices


Cassandra Erato


Recruiting, enrolling, and retaining participants are some of the most challenging aspects of clinical trials. Low recruitment numbers, enrollment delays, and dropouts lead to missed deadlines and increased costs. One report estimates that recruitment challenges can lead to delays of one to six months — delays that can cost from $600,000 to $8 million per day.

Phase I recruitment issues are a little different; not only do they affect the enrolling trial, but they also can affect all studies that follow. A program that is estimated to take 12 months can extend to 18 months or longer. That means fewer drugs on the market, less time to earn a profit, and less opportunity to bring vital medicines to patients.

For sponsors researching potential Phase I trial partners, we recommend you find out how your partners/potential partners are addressing the unique needs of healthy volunteers. How do they keep show rates high and timelines on track?  We recommend you consider the following Phase I recruitment best practices.

The Challenge of Recruiting Healthy Volunteers

Phase I studies are unique in that they typically require a small group of healthy volunteers who gain no health benefit from participating. While the United States has an abundance of qualified candidates, reaching these individuals and encouraging them to participate in your study takes a thoughtful participant recruitment plan.

Recruitment challenges unique to Phase I include:

  • Volunteers must be willing to spend anywhere from one day to up to six weeks at a clinic, depending on the nature of the study (inpatient or outpatient) and the protocol requirements.
  • Volunteers have to have reliable transportation to attend multiple appointments, especially for outpatient visits.
  • Volunteers may have to take time off work to participate.

At the height of the COVID 19 pandemic just recently, fears over virus exposure caused many healthy volunteers to decline participation. Out of the 23,000 individuals active in the prior 18 months at Spaulding, we noticed a 30% to 40% drop in the number of healthy adults willing to participate. Because of Spaulding’s expertise in Phase I studies and specifically in study recruitment, we were able to pivot quickly to fill our studies accordingly with little to no disruption to our sponsors’ trials.

Why Location Matters

Spaulding Clinical promotes clinical trials through a proprietary process that yields great success in outreach to individuals familiar and unfamiliar with clinical research.

Our Midwest location gives us a large target market. Spaulding Clinical is located in Milwaukee; its metro area reaches over two million residents. Nearby Chicago gives us another eight million more prospects. In addition, Wisconsin’s 80 universities and community colleges also adds to our great location. When considering a Phase I partner, sponsors should look for a CRO that not only has experience in multiple recruitment tactics, but also has access to a large number of participants.

Phase I Recruitment Best Practices

Recruiting during COVID-19 required a shift in strategy and messaging. With the combination of fewer individuals willing to participate and an increase in the number of clinical trials overall meant we had to think more strategically.

To recruit successfully for Phase I in the COVID era, our practices include the following:

1. Revolving Strategy. Phase I CROs need to develop clear, detailed recruitment timelines with built-in contingency plans. These plans should be shared with sponsors before screening. Working backward from first dose, Spaulding Clinical works with sponsors to determine when to start screening, when to start advertising, and other key milestone dates. We develop contingency plans for potential low recruitment and determine show rates based on possible COVID-19-positive volunteers. We conduct analyses of stipends for similar studies across the United States and are readjusting this plan almost daily. In essence, sites need to plan for every possible scenario and for every aspect of participant recruitment.

2. Ability to react quickly. If a Phase I unit typically has a 90% show rate at check-in and only 56% showed at check-in, that site has to move fast to make adjustments and contact the no-shows before the screening window closes. Some reasons this might happen would be a market change in stipend rates or difficulty in traveling due to current pandemic uncertainties.

If the site misses the screening window, it will have to start the screening process over for the participants lost. In either situation, time is of the essence. Delays lead to timeline extensions and additional screening costs. Only consider partners that can react and respond quickly to avoid trial delays.

3. Prepare for COVID-19 dropouts. COVID-19 testing, physical distancing, and infection prevention methods are common practice in Phase I sites. When recruiting for Phase I studies, expect at least an additional 5% dropout rate due to positive COVID-19 tests.

If you plan to enroll 50 people, check in 60 to 70 to account for both standard and COVID-positive dropouts. Over the last year, Spaulding Clinical has gained expertise in adjusting to protocols and recruiting processes to accommodate average COVID dropout rates.  Also look for a unit that can provide COVID testing results in less than 24 hours. Spaulding Clinical can get COVID test results in four to six hours, which means testing and admission can happen in the same day.

4. Upgrade the environment. Healthy volunteers don’t want to feel like they’re staying in a dorm, so sites shouldn’t resemble one. Most clinical research facilities put participants in units with 10 or more beds to a room and communal bathrooms.

Spaulding Clinical’s facility is a 200,000-square-foot unit that was formerly a hospital and includes 200 total beds, with two participants per room (a key benefit during COVID-19), private baths and showers, and laundry facilities. Our participants feel like they are at a hotel. We give participants nice toiletries, recreational opportunities, and high-quality food from our own cafeteria fully staffed with a master chef. Participants consistently compliment the chef and come back for the amazing meals.

5. Monitor the stipend. With more competition for fewer participants, Phase I studies across the board have increased stipends. We saw significant spikes in June and August 2020 and again in February 2021.

Your Phase I site should know the stipends in their region and inform sponsors of any rate spikes. A competitive stipend keeps show rates high.

Participants tend to sign up for the shortest-duration trial with the highest pay. They’re also attracted to single confinement studies to avoid extensive travel.

If you increase the stipend, sites should communicate the increase to current enrollees as well as participants who declined. If they’ve been screened, site staff may be able to change their minds.

If your study involves travel stipends, cover participants’ travel costs at the time of visit rather than partway through the study. Prompt reimbursement shows participants you are responsive to their needs, which improves retention.

Sponsors should be able to rely on their Phase I partner for information on the competitive landscape of trials in the area. In that vein, Spaulding Clinical provides its sponsors regular stipend analyses as part of its process to ensure studies are competitive and enrolled on time.

When developing a Phase I study, partner with a CRO that specializes in Phase I. Spaulding Clinical laser-focuses all of its efforts on Phase I. We have cardiac safety experts available in every conversation and our facility was purpose-built for Phase I and TQT studies.

With nearly 15 years of successfully recruiting Phase I studies and a 98% success rate, Spaulding Clinical is the leader in Phase I.


About Spaulding Clinical

A full-service, state-of-the-art paperless Phase I clinical trial testing facility and integrated CRO, Spaulding Clinical specializes in cardiac safety monitoring and provides the highest quality data to not only save biopharmaceutical clients time and money, but also uncover risks early in drug development. From our principal investigators to our highly trained nurses and CRO research staff, every employee is focused and committed to ensuring clean, high-quality data for Phase I trials and beyond. To learn more, visit


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