Feasibility and Investigator Selection


Non-commercial trials that fail to meet their targets often result in a request for further funding or may not achieve a statistically significant result. It is important to ensure that feasibility assessment and recruitment planning are considered during the study design and planning stage of a trial. For larger trials, the sponsor should consider, during the funding process, whether a feasibility or pilot study should be undertaken.

The Association of Medical Research Charities and the NIHR Medicines for Children Research Network have produced Points to consider when assessing the feasibility of research.  The US Clinical Trials Transformation Initiative (CTTI) have published a suite of Recommendations and Tools for Recruitment Planning that provide a useful framework.

MRC Hubs for Trial Methodology Research (MRC HTMR)

The MRC HTMR have published a range of material relating to feasibility and recruitment including:

Investigator Selection

For multi-site trials, the careful selection and evaluation of investigator sites is critical for the successful completion of a trial within budget, timelines and to ensure the generation of high quality data. Factors that should influence investigator site selection include:

  • Interest in the research question
  • Experience and qualifications of the investigator
  • Sufficient staff to conduct the study and their experience and qualifications
  • Availability of suitable patient population:
    • Anticipated rate of patient recruitment (determined through feasibility assessments)
    • Conflicting studies (competing for the patient population and potentially introducing recruitment bias)
  • Adequate time to conduct and oversee the trial
  • Adequate facilities:
    • Availability of any specialised diagnostic or therapeutic equipment required by the protocol
    • Adequate space and storage conditions (including archive)
    • Available resources in NHS support departments
  • Track record with similar trials previously
  • Geographic location
  • Contractual and budgetary negotiations and arrangements.

When undertaking site selection, the preparation of ‘reserve’ investigator sites (so that the trial may be extended to these sites if recruitment issues arise) should be considered as part of proactive trial planning.

Patient and Public Involvement (PPI):

The CTTI recommendations above stress the importance of patient and public engagement to improve trial success. The initiative includes a Stakeholder Identification and Analysis Tool to support this process. One study from King’s College London, published in the British Journal of Psychiatry showed that trials with higher levels of PPI were 4.12 times more likely to recruit to target. PPI can help shape a number of factors that can improve trial feasibility and recruitment by addressing questions such as:

  • Will the proposed recruitment strategy work? 
  • How could it be made easier for a patient to participate?  
  • How likely are participants going to accept the study schedule/requirements?

Further reading: