A feasibility study is a systematic preliminary investigation conducted before a clinical trial officially begins. It assesses whether the planned study is actually viable under the given conditions—with regard to patient availability, study site capacities, regulatory feasibility, and operational resources. Feasibility studies are a central instrument of clinical development planning and help to avoid costly false starts.
Objectives and Key Questions
The primary objective of a feasibility study is the early identification of risks and hurdles that could jeopardize the success of the planned main study. Typical questions include the availability of suitable patients (recruitment potential), the suitability of potential study sites, the acceptance of the study protocol among physicians and patients, and logistical aspects such as sample logistics, equipment availability, and study infrastructure. Additionally, the feasibility of the planned data collection is examined—for example, whether the eCRF design is practical and whether endpoints can be reliably collected under routine conditions. Results of a feasibility study flow directly into the revision of the study protocol and can lead to adjustments in inclusion and exclusion criteria, visit schedules, or site selection.
Site Feasibility vs. Patient Feasibility
In practice, a distinction is made between two main types: site feasibility and patient feasibility. Site feasibility assesses whether a study site meets the structural and personnel requirements for conducting a study. This includes the team’s GCP experience, existing infrastructure (e.g., equipment, laboratory, emergency equipment), capacities for the required patient volume, and the availability of the Principal Investigator. Patient feasibility, on the other hand, estimates how many suitable patients a site can realistically enroll. This involves evaluating patient data from hospital information systems, interviewing physicians, and in some cases, analyzing pre-screening data. Both analyses together enable a realistic recruitment forecast—incidentally, one of the most common criticisms in feasibility assessments is a systematic overestimation of recruitment potential by the sites.
Methods and Tools
Feasibility studies are generally conducted as questionnaire-based surveys (feasibility questionnaires) or as structured interviews with investigators and study coordinators. Digital platforms such as CTMS systems, site intelligence databases, or specialized feasibility tools (e.g., from IQVIA, Medidata, or Veeva) support the evaluation and comparison of multiple sites. The sponsor and CRO systematically evaluate the collected data and create a site ranking, which serves as the basis for site selection. In addition to quantitative criteria, qualitative factors are also considered, such as the motivation of the PI team, the historical reliability of the site, or the existing patient network.
Feasibility in a Regulatory Context
Although feasibility studies are not formally required by regulation, their implementation is viewed by authorities and ethics committees as a sign of diligent planning. Within the framework of EMA Scientific Advice procedures or meetings with authorities (e.g., End-of-Phase II meetings with the FDA), sponsors may be asked to explain their recruitment strategy and feasibility assessment. Well-documented feasibility data strengthen the credibility of the timeline and budget within clinical development plans (CDPs). For CROs, feasibility assessments are also a tool for bid calculation: realistic recruitment forecasts prevent contractual penalties due to delays and strengthen the sponsor’s confidence in the CRO’s operational competence.
Common Errors and Best Practices
Common errors in feasibility studies include unrealistic assessment of patient potential by sites, neglecting competing trials at the same location, and a lack of validation of the stated patient numbers through database queries. Best practices include standardizing the questionnaire across all sites, using benchmark data from comparable studies, and conducting a structured follow-up with potential study sites before final site selection is made. Open communication with sites regarding realistic expectations—rather than suggesting inflated numbers—improves the long-term partnership between the sponsor, CRO, and study sites.
Another underestimated aspect of feasibility is the cultural and linguistic dimension in international studies. In countries with different healthcare systems, varying standard-of-care treatments, or linguistic hurdles in the consent process, even well-structured protocols can fail. An interculturally sensitive feasibility analysis that takes national characteristics into account is therefore a decisive success factor, especially for global Phase III studies. CROs with an international network can provide valuable support here. Likewise, feasibility for decentralized clinical trial (DCT) elements should be assessed early: Are patients willing to use digital devices? Do sites have the technical infrastructure for remote monitoring and eConsent? These questions are increasingly becoming part of every feasibility assessment in modern study designs.
Frequently Asked Questions
When should a feasibility study be conducted?
A feasibility study should begin as early as possible, ideally during protocol development. This allows insights from the feasibility analysis to flow directly into the design of inclusion and exclusion criteria, the visit schedule, and site selection. Later corrections after the study has started are significantly more complex, time-consuming, and costly.
Who conducts a clinical feasibility study?
Feasibility studies are usually conducted by the sponsor or a commissioned CRO. Clinical operations teams contact potential study sites, collect data, and evaluate it. In some cases, specialized site intelligence service providers are involved, offering database analyses on patient populations and site experience.
How are feasibility results formally documented?
The results are summarized in a feasibility report, which contains the site ranking, recruitment forecast, identified risks, and recommendations for site selection. This report is filed in the Trial Master File and serves as the basis for sponsor decisions regarding site selection and resource planning. During regulatory inspections, it can be used as evidence of diligent study planning.