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 Medici Global model, showed 38% lower relative risk of drop out across four studies compared to those who were recruited by sites, with divergence across visits in all four studies. Since increasing sample size is typically associated with an increase in the statistical power of the study, the loss of subjects over the course of a trial can result in missed endpoints and negatively impact the outcome of the study. Engaging subjects that actively seek clinical trial participation results in a reduction of study withdrawals or patient dropout rates; the effect of which eliminates the need for over-enrollment of patients to offset expected retention loss. Increased retention rates accelerate enrollment timelines and result in saving time and money.