In order to aid the assessment and inform judegements related to clinical trial feasibilties we have a proposed decision-making framework based on industry and site-specific intervals of confidence that outline principles of acceptance, the logic for such acceptance, and an examination of proactive measures in response to the conclusions you have reached.


Confidence Level 1 – “Predictable” 
Definition: It is reasonably certain that you will meet your maximum enrolment target
Total Clinical Trial Load = 10-20%


Definition (Some or all may apply):

  • You have a profound understanding of the enrollable population and can make explicit, evidence-based estimations about rates of expected recruitment into the study.
  • You have a profound understanding of the type of intervention used in the study, which enables precise estimation of interest and appeal for the intended intervention.
  • You have an identifiable and specifically quantifiable database of appropriate size, relative to enrolment target, that:
    I. Is easily and ethically accessible
    II. Meets a desired criterion for inclusion
    III. Can be communicated confidently and promptly.
  • The protocol presents no readily apparent barriers to enrolment.
  • Your standard recruitment methods and referral sources are either not required or exceed the requirements for the study.
  • Enrolment time is not a considered a barrier.
  • The amount or quality of competing sites or studies is not expected to impact your own enrolment potential.
  • The prevalence of the indication of interest is significant (% of population).
  • Inclusion in the study presents an opportunity of well-established importance for potential participants.
  • Your staff are not only sufficient in number and availability, they are intimately familiar with this type of study and require little to no training or preparation to contribute enrolments to target.

Management Strategy:

  • Proceed with the study feasibility.
  • Consider negotiation of a higher or fixed allocation of enrolments.
  • Consider negotiation of higher per participant fees.
  • Consider negotiating for a reduction in total sites if appropriate.

Confidence Indicators:

  • Level 1 studies should represent at least 10-20% of total clinical trial load at any one time.
  • The possible return on investment associated with these studies exceeds the cost of capital to a point where the likelihood of profit outweighs the chance of loss so disproportionately that the value of participation is reasonably assured.
  • Level 1 studies support those of a lesser confidence level and facilitate growth, investment, and diversification of service capacity.
  • Level 1 studies may be ideal studies to onboard new investigators or justify the hiring of new staff as you can provide definitive assurances that relate to consistency of workload, potential for income, and accelerated professional development due to an assumed volume.
  • Level 1 studies enable you to accumulate important evidence about your maximal outputs, and thus potential.
  • Level 1 studies allow the production of well-known metrics that can be advertised and used as a vehicle for new study lead generation. (E.g. You may have an opportunity to be the only enroller or highest enroller).

Confidence Level 2 = “Probable”
Definition: It is reasonably probable that you will meet maximum enrolment target
Clinical Trial Load = 30-40%


Definition (Some or all may apply):

  • You have an assured understanding of the enrollable population and can make informed estimations about rates of expected recruitment into the study.
  • You have an assured understanding of the type of intervention used in the study, which enables reasonable estimation of interest and appeal for the intended intervention.
  • You have an identifiable and reasonably quantifiable database of appropriate size, relative to enrolment target, that:
    I. Is ethically accessible
    II. Largely meets a desired criterion for inclusion
    III. Can be communicated confidently and promptly.
  • The protocol design presents mostly qualifiable and manageable barriers to enrolment.
  • Your standard recruitment methods and referral sources are required, although may be inadequate to meet maximum enrolment targets without additional support for the study.
  • Enrolment time is an influential but manageable factor.
  • The amount or quality of competing sites or studies is expected to pose a small limit to your own enrolment potential.
  • The prevalence of the indication of interest is substantial.
  • Inclusion in the study presents an opportunity of reasonably assumed importance for potential participants.
  • Your staff are sufficient in number and availability, and are reasonably familiar with this type of study, but may require new training or adoption of new competence to contribute enrolments to target.

Management Strategy:

  • Proceed with the study feasibility.
  • Consider cautious estimation of enrolment targets (e.g. Divide Level 1 feasibility enrolment estimates by 2).
  • Consider reducing your high-end enrolment targets to offset risk.
  • Per participant fees should represent your baseline or standard fees.
  • These studies may be profitable, but you may underperform against your maximum enrolment targets or industry peers.
  • These studies may be difficult to realise when and where corrective action needs to be taken.
  • You may need to employ advanced strategies to prevent underperformance issues associated with the study, such as:
    I. Motivation and production from coordinators.
    II. Complacent business management.
    III. Aggressive Recruitment strategies and advanced pre-screening.
    IV. Formalise mutual processes to assure efficiency with 3rd party providers that you depend upon.
  • Encourage protocol design input. There may be 1-2 inclusion criteria that affect enrolment projections that can be altered.

Confidence Indicators:

  • Level 2 studies should represent at least 30-40% of clinical trial load at any one time.
  • Level 2 studies support those of a lesser confidence level and provide the most regular source of income, security, and largely ensure sustainability.
  • Through repetition, Level 2 studies will become Level 1 opportunities.
  • Competition in enrolment is often healthy in multisite Level 2 studies and you can learn a great deal about superior management strategies and potential of other stakeholders.
  • Assume that your staff may need to undertake specific training that may be new or completely distinct from previous experience or study involvement.
  • Level 2 studies may still be ideal to onboard new investigators or staff as you can provide reasonable assurances that relate to consistency of workload, potential for income, and professional development due to an assumed volume.
  • Level 2 studies enable you to accumulate important evidence about your most common outputs, and thus justification of standard operating processes.
  • Level 2 studies allow the production of well-known industrial metrics that can be advertised and used as a vehicle for new study lead generation

Confidence Level 3 = “Possible”
Definition: It is reasonably possible that you meet maximum enrolment target
Clinical Trial Load = 20-30%


Definition (Some or all may apply):

  • You have a modest understanding of the enrollable population and can make plausible estimations about rates of expected recruitment into the study.
  • You have a modest understanding of the type of intervention used in the study, which enables limited estimation of interest and appeal for the intended intervention.
  • You have a limited but identifiable and reasonably quantifiable database relative to enrolment target, that:
    I. Is ethically accessible
    II. Partially meets a desired criterion for inclusion
    III. Can be communicated confidently and promptly.
  • You may reserve responsible safety concerns associated with the therapy and wish to measure your enrolment targets accordingly to offset or control the risk potential.
  • The protocol design presents a combination of mostly known and quantifiable barriers to enrolment but also some unknown and unqualifiable potential barriers for enrolment.
  • Your standard recruitment methods and referral sources are required but are inadequate to meet maximum enrolment targets without additional support for the study.
  • Enrolment time is expected to restrict capacity to enrol to maximum target.
  • The amount or quality of competing sites or studies is expected to pose a significant limit to your own enrolment potential.
  • The prevalence of the indication of interest is modest.
  • Inclusion in the study presents an opportunity of limited importance for potential participants.
  • Your staff are likely insufficient in number and/or availability, and they are reasonably unfamiliar with this type of study and require new training or adoption of new competence to contribute enrolments to target.

Management Strategy:

  • You may consider not proceeding with these feasibilities due to risk profile.
  • Be upfront, transparent, and constructively critical with your enrolment concerns with study sponsors. This will serve you well in difficult or slow recruiting studies, particularly in the long-term.
  • The presence and study load of higher confidence level feasibilities may provide responsible rationale for acceptance.
  • Consider reducing your high-end and minimum enrolment targets to offset risk.
  • Consider cautious estimation of enrolment targets (e.g. Divide Level 1 feasibility enrolment estimates by 3).
  • Per participant fees should represent your baseline or standard fees.
  • You may need to employ advanced strategies to prevent underperformance issues associated with the study, such as:
    I. Motivation and production from coordinators
    II. Complacent business management
    III. Aggressive Recruitment strategies and advanced pre-screening
    IV. Formalise mutual processes to assure efficiency with 3rd party providers that you depend upon.
  • Encourage protocol design input. There are likely multiple inclusion/exclusion criteria that affect enrolment projections that can be altered.

Confidence Indicators:

  • These feasibilities should represent no more than 20-30% of clinical trial load at any one time as a counter measure to conceivable overburden of liability.
  • Level 3 studies support those of a lesser confidence level and represent a modest level of income, support growth of trial diversity, exposure to new areas of interest for investigators, and involvement in investigations for unique indications.
  • Through repetition, Level 3 studies will become Level 2 opportunities.
  • Competition for enrolment may be healthy in multisite Level 3 studies and you can learn a great deal about superior management strategies and potential of other stakeholders.
  • Assume that your staff require specific training that may be new or completely distinct from previous experience or study involvement.
  • Level 3 studies may be investigations that you are attempting for the first time, such as a completely new indication or unfamiliar intervention, you may be working with a new investigator for the first time, you may be employing a new trial coordinator.
  • It is reasonable to assume at least some inconsistency of workload, inhibition of income potential, and difficulty using these studies as a regular means of internal professional development.
  • Level 3 studies enable you to accumulate important evidence about some of your weakest areas of competence and thus help to identify measures and improvements that may be implemented to develop and grow strength.
  • Level 3 studies may or may not allow the achievement of well-known industrial metrics that can be advertised and, as a result, may not be an effective vehicle for new study lead generation.
  • These are not ideal studies to stimulate organisational growth or justify hiring more staff.

Confidence Level 4 = “Exploratory”
Definition: It is highly unlikely that you meet minimum enrolment target
Trial Load = 10-20%


Definition (Some or all may apply):

  • You have a minimal understanding of the enrollable population and can only make very basic or vague estimations about rates of expected recruitment into the study.
  • You have a minimal understanding of the type of intervention used in the study, which prevents accurate estimation of interest and appeal for the intended intervention.
  • You have a database that is difficult to identify and appropriately quantify relative to enrolment target.
  • You are largely unable to pre-qualify potential participants against the desired criterion for inclusion.
  • You may reserve responsible safety concerns associated with the therapy and wish to measure your enrolment targets accordingly to offset or control the risk potential.
  • The protocol design presents a combination of both known and many unknown or unqualifiable potential barriers for enrolment.
  • Your standard recruitment methods and referral sources are expected to be largely inadequate to meet minimum enrolment targets without additional support for the study.
  • Enrolment time is expected to restrict capacity to enrol to minimum target.
  • The amount or quality of competing sites or studies is expected to pose a drastic restraint to your own enrolment potential.
  • The prevalence of the indication of interest is less than 5% of the population.
  • Inclusion in the study presents an opportunity of obscure importance for potential participants.
  • Your staff are likely insufficient in number and/or availability, and they are completely unfamiliar with this type of study and require considerable training or adoption of new competence to contribute enrolments to minimum target.

Management Strategy:

  • You should only consider proceeding with these feasibilities for reasons of exclusivity, exploratory or verification reasons.
    I. You may have a unique relationship with the developer or sponsor that allows acceptance of such a feasibility
    II. You may want to explore a new therapy or indication
    III. You may want to verify or test internal trial management systems.
  • Be upfront, transparent, and constructively critical with your enrolment concerns with study sponsors. This will serve you well in these difficult or slow recruiting studies, particularly in the long-term.
  • The presence and study load of higher confidence level feasibilities may provide responsible rationale for acceptance.
  • Consider reducing your high-end and minimum enrolment targets to offset risk.
  • Consider cautious estimation of enrolment targets (e.g. Divide Level 1 feasibility enrolment estimates by 4).
  • Per participant fees may need to be proportionally higher than standard fees due to the limited capacity to enrol.
  • You will need to employ advanced strategies to prevent underperformance issues associated with the study, such as:
    I. Motivation and production from coordinators
    II. Complacent business management
    III. Aggressive Recruitment strategies and advanced pre-screening
    IV. Formalise mutual processes to assure efficiency with 3rd party providers that you depend upon.
  • Encourage protocol design input. There are likely multiple inclusion/exclusion criteria, follow up schedule and other interventions that affect enrolment projections that can be altered.

Confidence Indicators:

  • These feasibilities should represent no more than 10-20% of clinical trial load at any one time as a counter measure to conceivable overburden of liability.
  • Level 4 studies provide an insignificant level of income, allow unique examination of noteworthy trials, promote exposure to new areas of interest for investigators, and involvement in investigations for uncommon or rare indications.
  • Although difficult, through repetition, Level 4 studies will become Level 3 opportunities.
  • Competition for enrolment may be extreme in multisite Level 4 studies or comparably limited across all sites
  • Assume that your staff require comprehensive and specific training that may be new or completely distinct from previous experience or study involvement
  • Level 4 studies may be investigations that you are attempting for the first time, such as a completely new indication or unfamiliar intervention, you may be working with a new investigator for the first time, you may be employing a new trial coordinator.
  • Level 4 studies represent inconsistent workloads, low income potential, and difficulty developing management acumen.
  • Level 4 studies enable you to accumulate important evidence about completely distinct areas of clinical trials and thus help to identify measures and improvements that may be implemented to develop and grow competence.
  • Level 4 studies provide a very low chance of achieving industrial metrics and, as a result, are not an effective vehicle for new study lead generation.
  • These are not ideal studies to stimulate organisational growth or justify hiring more staff.

Dom Bailey