Most clinical trials fail to meet their enrolment timeline, causing research studies to be delayed due to recruitment problems. The costs associated with delaying a drug is estimated to be 40,000 USD per day of delay. So how come the pharmaceutical industry hasn’t fixed the problem?

How do I ensure my clinical trial meets the enrolment target and timeline? This is probably one of the most frequently asked questions among clinical operations staff in the pharmaceutical industry.

They are aware of the high risk of ending up among the majority of clinical trials being delayed due to recruitment problems.

They are also aware of the negative consequences that follow with the delay of the clinical trial.

So, if they know the bad odds, the risks and the negative consequences of not being successful with the enrolment of trial participants, why is it that nothing has significantly changed?

To explain this, we will have to look at how clinical trials traditionally have found participants.

Sites Taking Care of Recruitment and Enrolment

Clinical trials sites have historically been the primary resource for sponsors to find trial participants. Outside of clinical trials, sites most often function as clinics in which they are in daily contact with the patients and help with their everyday treatment of their diagnosis.

This has been, and is also still today, the most frequently used method to find clinical trial participants. But it’s rarely sufficient to reach the enrolment target of trial participants within the enrolment timeline.

The performance of each trial site can differ based on different variables such as resources, capacity, specialty, priorities etc. But clinical trial sites risk overestimating their capability to meet the sponsors’ enrolment target over time.

This is because the projection of the enrolment is often projected to be linear but more often results in a saturation curve that over time flattens out or stagnates.

This misalignment between the enrolment projection and actual recruitment development is due to the fact that most sites start out with enrolling the patients with the highest likelihood to enroll in the clinical trial. These patients are also the ones who are in the easier cohort of potential trial participants with less strict inclusion and exclusion criteria.

To put in plain words; clinical trial sites start out with recruiting the ones with the highest chance of enrolling in to the clinical trial, leaving the more difficult ones for later, ending up overestimating their long-term deliverability of trial participants.

This often results in a flattening recruitment curve and the clinical trial sponsor ending up in a recruitment pickle because according to their projection the start pace should have continued to develop linear but are now stagnating.

As seen in the picture below from q1 year upon til Q2 Year 2, which was where the recruitment vendor was introduced as a rescue.

A graph displaying the recruited randomized patients for a clinical trial which James Lind Care was hired to support from year 2, Q2.

Digitalization Has Changed the Dynamic

So how do you ensure not to end up in the stagnation of enrolling trial participants?

Before answering this question, I want to expand the focus broader to how our society has changed drastically throughout the last 30 years due to digitalization.

Imagine what you do when you are looking to fix a problem in your everyday life?

I bet you search and browse online, correct? You might even ask ChatGPT for advice.

Well surprisingly enough, most patients do the same.

There are studies showing that 90% have never discussed participation in clinical trials with their GP., making it clear that there is a huge, untapped potential in reaching patients who haven’t been in dialogue about clinical trials via the healthcare system.

Meanwhile, more than 30% of US adults have already prompted ChatGPT about receiving and seeking health and treatment advice.

But even more importantly, a study from 2025 surveying patients’ insights showed that patients mainly hear about clinical trials online.

from CISCRPs 2025 Patients Insights Study

All of this clearly points in the direction that when you are looking to recruit patients for your clinical trials, you can’t solely rely on sites to find them and you have be present online and use digital advertising to recruit participants.

Before digitalization of society, sponsors had few options other than to approach trial sites when searching for potential trial participants. However, thanks to digitalization, it is now possible to reach most potential trial participants who have never discussed taking part in clinical trials with their GP or the healthcare system.

Today, patient recruitment for clinical trials is largely about understanding how to advertise on digital and social media.

So as a clinical trial sponsor you have to prioritize and allocate resources to patient recruitment companies that understands how to recruit online.

Enrolment and Recruitment Are Two Separate Disciplines

In my experience, sites are experts in enrolment, but they are not experts in recruitment.

They are excellent at screening potential trial participants, having dialogues with eligible patients and supporting clinical trial participants.

But I have never heard a clinical trial site say they enjoy developing trial advertisements or spend time on running and optimizing online recruitment campaigns. It’s a completely different discipline that requires different skills. But in many clinical trials, it seems that these two disciplines are not being distinguished.

Enrolment and recruitment are two separate pieces in the clinical trial puzzle that fit together when each of them is being carried out professionally and with respect for each other’s importance.

Understanding, acceptance and execution of the distinction between the two disciplines also offer an important lesson for providers of patient recruitment services.

Good recruitment should ease the enrolment of trial participants for the clinical trial sites. Good recruitment isn’t about reaching a high number of referrals. It’s about the quality of the referrals to the sites.

Sites don’t want to collaborate with patient recruitment companies that don’t understand enrolment. This lack of understanding is reflected in how recruitment ends up overburdening the sites with bad referrals.

These referrals might match the initial in-/exclusion criteria, but when screened by medical staff, they do not meet the specific medical criteria, or they turn out to be less motivated because they have not been properly informed about participation in the clinical trial.

These examples results in failed enrolment due to overburdening the sites with low-quality referrals. And these examples are, unfortunately, something many sites have experienced which have made them hesitant to partner with a patient recruitment service provider.

Patient recruitment companies must realize that good patient recruitment is based on an understanding of enrolment as a discipline. Good recruitment is tailored to meet the needs of sites so they are in a better position to perform successful enrolment.

Sponsors must consider recruitment and enrolment as two separate disciplines that require different professional skills, while ensuring that all parties involved understand and respect both disciplines.

The Recipe for Successful Patient Recruitment

Answering how to perform successful patient recruitment, relies on an understanding of the enrolment discipline and where problems can arise if too much emphasis is placed on a patient-centric approach and not on a site-centric approach.

The clinical trial sponsor should prioritize selecting patient recruitment companies that are experts in digital engagement and recruitment of patients in clinical trials but also display a professional understanding and respect for the enrolment discipline.

Furthermore, the sponsor should prioritize selecting and activating sites that are open to collaborate with recruitment vendors that can support and boost each sites’ enrolment to ensure the sponsor doesn’t end up with the saturation recruitment curve, and ultimately risk ending up where the vast majority does with a clinical trial that is delayed.

If you need the recipe simply put:

- 1 X Sponsor accepting that enrolment and recruitment are two different disciplines and therefore allocates resources to hire a patient recruitment company for the clinical trial

- 1X Patient Recruitment Company that are experts in digital engagement and recruitment for clinical trials, but more importantly understands and respect the enrolment discipline and performs site-centric recruitment.

- Add own choice of number of Sites that are willing to collaborate with a patient recruitment company to improve their enrolment of trial participants.

Ensure to mix these three ingredients together via shared dialogues, and let it stur for some time, and you will end up with a very successful patient recruitment for your clinical trial that is completed on time.