Online Resource for Recruitment Research in Clinical Trials

Welcome to the ORRCA project

The ORRCA project (Online Resource for Recruitment research in Clinical triAls) aims to bring together published and ongoing work in the field of recruitment research into a searchable database. 

When searching, please note the database is still being updated on a regular basis and currently contains 2650 articles. To see more about our the methodological approach and the latest progress click here.

Advanced Search

If you use the ORRCA database, please reference it in any reports or publications by including the following statement: Articles were identified through a search of the ORRCA recruitment research database (


To keep informed about the ORRCA project please sign up to our mailing list here.

If you are currently working on a project that you think is relevant then you can also submit this to ORRCA using the “tell us about a new project/study form”.

For more information  or to suggest an alternative classification for an article please email us using our contact page