How well do you know your clinical trial patients? Crohn’s disease

The clinical trial patient can sometimes be different from the patient found at a typical doctor’s office. Looking at patients with Crohn’s disease that responded to a Clariness ad about a clinical trial, we can see some differences.

We recently ran online advertisements seeking patients with Crohn’s disease. Patients from Australia, Belgium, Canada, Czechia, Denmark, Germany, Hungary, Poland, Netherlands, United Kingdom and United States responded to the ads.

After reading the trial information, the patients completed an online screener with questions related to the protocol criteria.

For this exercise, we are using the names “Study Patient” for those patients that completed the online screener and “Clinic Patient” for which we used data from medical literature. Understanding the differences between the two groups could help when drafting a protocol by ensuring that the patient population exists to meet the trial’s enrollment goal.


Although the disease affects males and females equally in the clinic setting, more women (66%) responded to the study ads.

Location of Crohn’s disease:

Clinic Patients and Study Patients have similar rates of colon and small intestine involvement 92% vs 91%, respectively.

History of resection:

It is estimated that 3/4 of patients will eventually require surgery. About 1/3 of Study Patients reported having extensive colonic resection (partial or total colectomy).

Fig. 1

Short bowel syndrome

About 1/4 of Study Patients reported short bowel syndrome or more than 3 small bowel resections.

Active perianal fistula

There is a similar rate of perianal fistula between the groups: 25% of Clinic Patients vs 30% of Study Patients. Of those Study Patient with a fistula, 40% report that treatment is not successful.

TNF-a inhibitor treatment

In the Clinic Patient, the rate of biologic use varies by country, ranging from 8-25%. Only a small percentage of Study Patients are receiving TNF-α inhibitors for their Crohn’s disease. A third of  Study Patients don’t know what type of drug they are taking. It is not known how many of these Study Patients might in fact be currently treated with a TNF-α inhibitor.

Fig 2

Want to know how we can support your patient recruitment?