Replacing Study Subjects

Case Studies


Figures presented at a recent North Carolina pharmaceutical conference show that 50% of the clinical sites selected to conduct a clinical trial will enroll zero or only one subject.  Even with the advent of social media initiatives and other creative new ways to boost recruitment, enrolling an adequate number of subjects in a timely fashion remains a critical issue for the drug development industry.  Eligible subjects, in a word, are precious.

Precious, too, are randomization schedules and statistical design. A second wave dilemma comes after an eligible subject is finally enrolled, assigned to the next slot in the randomization schedule, and then turns out to be, for one reason or another, a case of early withdrawal.  Not only does this impact the goal of a treatment group’s minimum number of subjects, but –importantly - it impacts the balances and ratios built into the study randomization schedule at study startup.

Is there any way Interactive Response Technology (IRT/IWR/IVR) can help?


When vetting an IRT system, be sure it includes as one of its core offerings a validated Subject Replacement functionality.

Veracity Logic’s VLIRT® system provides a user-friendly option for easily replacing early withdrawers with a new subject assigned to the same treatment group. The Subject ID and RandID for the new subject are unique, drawn from a replacement pool within the randomization structure – but the treatment assignment is the same. The integrity of the randomization design is maintained, without additional manipulations and negative impact on biostatistical analyses.

Contact Us Today to Learn More!

Share this Post