Patient recruitment is the process of recruiting patients for a clinical study. CROs (Clinical Research Organizations) generally outsource a patient recruitment company do the job of getting patients. The recruitment company employ diverse mechanisms to advertise the study they are conducting. Most companies also have their own database from there they can cull the required numbers and sell it to the CROs. But at the heart of all this is the recruitment company to patient communication. How can the recruitment company be in constant contact with the patients?