Clinical Trial Feasibility Assessment: How to Evaluate a Study Before You Commit

A sponsor sends you a feasibility questionnaire. You fill it out, estimate your patient volume, and agree to an enrollment target. Then the study opens — and the patients aren't there.

This is the most common failure mode in clinical trial enrollment, and it's almost entirely preventable. Not because the site lacked patients, but because no one modeled how many patients would actually qualify under the protocol criteria, within the timeline, in that geography.

This guide is written for research sites — PIs, directors, coordinators — who want to run an internal assessment before committing to a study. The kind of assessment that tells you whether a target is realistic before it's in an agreement, not after you're already behind.

Two Kinds of Feasibility — and Why Most Sites Only Run One

There are two distinct feasibility processes in every clinical trial, and they serve opposite purposes.

The first is the sponsor's assessment of your site: your staff experience, infrastructure, regulatory history, patient volume, and PI qualifications. This is what the questionnaire is for. The sponsor is deciding whether your site is capable of running the study.

The second is your assessment of their study: whether the protocol's eligibility criteria match your real patient population, whether the visit burden fits your capacity, and whether the enrollment target is achievable within the timeline. This one is entirely your responsibility — and almost no one covers it.

Every published guide on clinical trial feasibility is written to help sponsors evaluate sites. The site-side assessment has no established process, no published template, and no industry standard. That's the gap. And it's where most enrollment commitments go wrong.

Four Things Worth Assessing Before You Commit

Why Sites Consistently Overcommit

These are not random failures. They follow a predictable pattern, and the root cause usually traces back to the same moment: when the site agreed to a target.

Sponsor feasibility questionnaires are designed to identify interest and capability, not to pressure-test enrollment projections. They ask whether you have relevant experience, a qualified PI, and a patient population in the relevant condition area. Sites that answer yes to all three are considered feasible. The actual enrollment calculation is rarely done rigorously.

There's also a social dynamic. Sites that express cautious projections may lose the study to a more optimistic competitor. The incentive structure rewards confidence, not accuracy. So sites project high, win studies, and then spend months trying to close a gap they could have anticipated.

An internal site-side assessment changes that dynamic. When you know what your realistic monthly enrollment rate is, you negotiate from data rather than intuition. Sponsors respond well to sites that come with their own numbers — it signals operational maturity, and it makes eventual enrollment performance more predictable for both sides.

The Three Numbers Every Site Should Know

Before answering any sponsor feasibility questionnaire, a site should be able to state these three numbers with reasonable confidence:

1. 1Your eligible patient pool — how many patients in your EMR and catchment area meet the core inclusion and exclusion criteria for this protocol.
2. 2Your realistic monthly enrollment rate — based on your historical screen-fail rates for similar indications and your current coordinator capacity, how many patients per month can you realistically move from inquiry to randomization.
3. 3The required monthly rate implied by the sponsor's target and timeline — the number you need to hit to fulfill the commitment.

If your realistic monthly rate is lower than the required rate, you have three options: negotiate the target down before signing, add recruitment resources that can close the gap, or decline the study. All three are better outcomes than committing to a number you cannot hit.

How to Run a Quick Internal Feasibility Assessment

You don't need a CRO or a data science team to run this. A working version takes a few hours and uses data your site already has.

What Sites That Consistently Hit Their Targets Do Differently

High-performing sites treat the sponsor's feasibility process as a trigger for their own assessment, not a substitute for it. They fill out the questionnaire, then run the internal calculation independently — and they use the result to negotiate.

Sponsors respond well to sites that come with data. A site that says "our EMR analysis gives us 65 eligible patients; based on our screen-fail history, we project 8 to 12 randomizations over 10 months" is a different kind of site than one that commits to 15 based on general impressions. The realistic number is more useful to the sponsor even if it's lower.

This same posture applies to recruitment partnerships. Sites that have run their own feasibility assessment can evaluate whether a recruitment vendor's projection is realistic, rather than accepting a lead volume estimate that doesn't account for local eligibility rates or competition.

The guide on clinical trial enrollment challenges covers what to demand from recruitment partners and how to structure accountability before a campaign starts. The feasibility assessment is what tells you whether any partner's projected outcome is achievable before you commit.