The Critical Issues Sites Need to Track During a Clinical Trial – Part Three – Enrollment

Congratulations! You have gone through all the necessary steps to launch a clinical trial. Now it’s time to move on to the next one, right? Wrong! A successfully managed clinical trial requires ongoing tracking throughout its duration. Careful tracking ensures your research organization remains compliant and that your site is compensated properly for the study.

Follow our series on the key critical issues you need to track throughout a clinical trial.

Part Three — Enrollment

One of the most pressing reasons why clinical trials are delayed is low enrollment. According to a Tufts University study, nearly half of clinical trials do not meet their participant enrollment goals.

Many of these challenges need to be addressed before a site determines that they will participate in a clinical trial. A realistic assessment, or feasibility study, of a site’s enrollment potential can minimize the risk of low enrollment later. The assessment may include an evaluation of your patient population, community demographics, prevalence of the disease being studied, and so on.

Enrollment and Sponsor Billing

Accurate enrollment tracking is directly tied to the ability to invoice study sponsors, which has an impact on cash flow for your site.

Typically sites provide data to study sponsors in real time when they enroll participants and when participants complete study visits and procedures throughout the course of their participation in the study. Sites should also be tracking their enrollment information internally at least monthly, and comparing  the actual number of participants enrolled against what was originally estimated. Regular tracking allows a site to notify the study sponsor of possible problem areas early in the process, when enrollments seem to be falling behind original targets.  If other sites are experiencing difficulty meeting enrollment targets an intervention, such as a protocol amendment, may be necessary. Coaching on recruitment techniques could also be helpful.

Include “Screen Failures”

The number of enrolled study participants is not the only critical metric. Sites should also track the number patients who go through the screening process, but for some reason are not qualified to participate in the study. These are called “screen failures.” Often sponsors will include a certain amount of reimbursement in the study budget for screen failures, Therefore it is important to track and invoice sponsors in accordance with the study budget.

Additionally, a high number of screen failures can signal an issue with the protocol’s inclusion and exclusion (eligibility) criteria. A screening log that includes information about the reason for exclusion can be important in a “root cause analysis” if enrollment goals are not being met.


Not only is it important to track initial enrollment, but sites need to monitor retention, or when a patient drops out of a study for any reason. Dropout rates can have implications for analysis. Having an “early warning” system in place to identify high dropout rates gives sites the opportunity to mitigate the problem.

Tracking the study procedures for participants who may terminate from the study early is also important. Sites should be paid for all study procedures performed up to the point of termination.

Besides the budget implications, a site can gain critical insights in tracking detailed enrollment data, which can then aid them in making future decisions about participating in trials. These “lessons learned” can assist a site in being more successful in future clinical trials.