Defining recruitment feasibility

While there are some general standard operating procedures (SOPs) available to research sites for guiding a feasibility assessment,⁴ sponsor companies have only just begun to define their own SOPs.

"We consider strategic feasibility to be part of a global clinical development plan for a compound or protocol," Neidl said. "It's a high-level process taking into consideration the market strategy, disease incidence and prevalence, regulatory approach, and country selection, and maybe some preliminary idea for an investigator strategy, such as specialty selection and mix of generalists and specialists."

Figure 1. Example of factors assessed in a site survey.

Indeed, within the broader scope of operational feasibility for a clinical trial, recruitment feasibility is the process for determining the time frame and parameters necessary for successful recruitment.

For the purposes of exploring new methods for improving clinical trial enrollment planning and execution, we propose the following definition of recruitment feasibility.

Recruitment feasibility is the process by which a clinical study sponsor can forecast and manage the probable randomization rate (number of patients per site per month) for a specific protocol and determine realistic parameters for site enrollment months (number of sites multiplied by number of open-to-enrollment months).

With this in mind, study planners must consider each of the following factors through a recruitment lens.

Protocol design. How would each group of study community members respond to this protocol—regulators, investigators, coordinators, project managers, monitors and patients? In what ways might the protocol design be off-putting to one or more of these groups, and can that be changed, or must it be mitigated? Can we afford to prioritize one group over another?

Country. While there may be many business reasons to include a specific country—such as market importance, regulatory barriers affecting speed to market, existing relationships with investigators, cost of conducting—none of these exempts a country from a recruitment feasibility assessment. From a recruitment perspective, the goal is not merely to determine which countries should be included, but what will it take within each country under consideration to succeed? What level of recruitment support may be required to offset protocol design challenges?

Sites. What types of investigators are most likely to be high enrollers for this study? Will that vary by country? Do we have a platform for contracting specific sites in each selected country? What are the likely enrollment rates for sites in each country? Site surveys play an important role in assessing recruitment, however most current models co-mingle recruitment feasibility with site selection—a near guarantee for collecting misleading information.

Patient. While it may seem obvious to include patient perspectives in the recruitment feasibility process, it is a rare sponsor that consistently asks patients for their input. More often than not, investigators, key opinion leaders, or country managers are used as surrogates for patients.

Brendan O'Neill, Manager in the Patient Recruitment Specialist Group at Merck and Co., agreed with this sequence, "We approach recruitment feasibility in that order—country, site, and patient. It's great to consider the patient level, but if the protocol won't be approved in a country, you're wasting everyone's time."

Indeed, from a patient recruitment perspective, these four key considerations are the root of most enrollment barriers and certainly a thorough analysis of a given protocol will provide the necessary insight regarding ideal study countries, sites, and ways and means to reach the patients most likely to value study participation. Assuming that we know our protocol and our patients well, let's focus on some key considerations for country and site assessment and selection and how qualitative data collection strategies can be applied universally for all studies, and ultimately applied to a feasibility formula to generate quantitative insights for successful study planning.