Selection of research sites in a clinical trial – who is responsible and how to do it effectively?
The selection of appropriate research sites is one of the key factors determining the success of a clinical trial. At this stage, the pace of patient recruitment, data quality, and the overall operational risk of the project are largely defined. In practice, sponsors often have their own list of preferred sites or investigators; however, even in such cases, independent verification and feasibility assessment—typically conducted by a CRO—are essential.
Formally, the sponsor is responsible for selecting research sites, as they make the final strategic decisions and bear regulatory responsibility for the project. At the same time, the process of identifying and qualifying sites is very often carried out in collaboration with a CRO partner, which brings local operational expertise, access to a network of proven sites, and knowledge of realistic recruitment capabilities within a given therapeutic area.
Planning the selection of sites should begin already at the study concept stage. It is crucial to analyze the patient population, competing trials conducted in parallel, and investigators’ experience in similar projects. A site with a strong scientific reputation does not always guarantee fast recruitment—equally important are organizational resources, availability of study staff, infrastructure, and the quality of previous collaboration in clinical trials.
The sponsor may provide a list of recommended sites based on prior projects or scientific relationships. Such a list is a valuable starting point but should be subject to an objective feasibility assessment. Verification conducted by a CRO helps confirm the actual recruitment potential, availability of the target patient population, investigator workload, administrative readiness of the site, and compliance with protocol requirements. Lack of such analysis is one of the most common causes of recruitment delays in clinical trials.
The feasibility process typically includes analysis of the site’s historical performance, feasibility questionnaires, direct communication with the research team, and assessment of local regulatory and contractual conditions. Based on this, it is possible to realistically estimate the number of patients, site activation timelines, and potential operational risks. As a result, the sponsor receives not only a list of sites but, more importantly, a strategic recommendation regarding the optimal structure of the study network.
It is worth noting that effective site selection is not simply about maximizing the number of sites. An excessive number of low-performing sites generates additional start-up, monitoring, and project management costs without improving study efficiency. Increasingly, the preferred approach is to select a smaller number of carefully validated sites with high recruitment potential.
Experienced CROs support sponsors at every stage of this process—from site identification, through feasibility and strategic recommendations, to preparation for study activation. Biostat experts assist in verifying both new locations and sponsor-recommended sites, ensuring an objective assessment of their operational readiness and actual ability to deliver the project.
If you are planning a clinical trial and want to ensure that site selection translates into efficient recruitment and a stable study course, CRO support at the feasibility stage can significantly reduce risk and optimize the start-up strategy from the very beginning of the project.
