Patient recruitment methods can have a significant effect on the retention of subjects in clinical trials; these effects can result in considerable cost implications. Subjects that actively sought clinical trial involvement through an online pre-screener (in response to online clinical trial advertising) using the MediciGlobal model, showed 38% lower relative risk of drop out across four studies compared to those who were recruited by sites [95% Confidence Interval (CI) 19%–53%], with divergence across visits in all four studies. Clare Jackson Strategic Program Manager, Utku Ozdemir Director of Business Analytics, and Liz Moench President at MediciGlobal deal with Clinical Trial Retention Meta-Analysis and Patient Recruitment methods.