RECRUITment In randomized clinical Trials


RECRUIT-IT will help investigators to improve the planning and estimating of participant recruitment during trial conduct.

Poor recruitment is the main reason for premature discontinuation of RCTs, which raises a main question for trial investigators during the planning and conduct of RCTs: how long will it take to recruit the target number of patients? Or once a trial has already started, how long will it take to recruit the remaining number of patients until the target sample size is reached? Evidence-based guidance and tools are needed to predict and monitor participant recruitment in RCTs.

Therefore, we propose this project to provide empirical evidence on the patient recruitment process of 300 completed or discontinued RCTs, determine pivotal time points and criteria for the assessment of recruitment progress in RCTs, validate existing recruitment models, and develop a hands-on guidance and user-friendly tools to support participant recruitment in RCTs.

Study protocol:

Kasenda B, Liu J, Jiang Y, et al. Prediction of RECRUITment In randomized clinical Trials (RECRUIT-IT)-rationale and design for an international collaborative study. Trials. 2020;21(1):731. Published 2020 Aug 21. doi:10.1186/s13063-020-04666-8

Contact person:

Matthias Briel

Ala Taji Heravi



Study Center of the German Society of Surgery (SDGC), University of Heidelberg



German Chronic Lymphocytic Leukemia (CLL)



Swiss Group for Clinical Cancer Research (SAKK)



Bern Clinical Trial Unit



Clinical Study Data Request


The Virtual International Stroke Trials Archive (VISTA)


Derby Clinical Trial Support Unit