Abstract: In a clinical trial program screening method, potential clinical trial candidates are driven to a screening website by, for example, banner ads, text messages, or other electronic advertisements. When a respondent clicks the advertisement, a multiple level screening method is conducted to screen qualified candidates for participation in a clinical trial program. Diagnostic, demographic and/or geographic data are collected from respondents and used to screen for predetermined clinical trial participation criteria. The effectiveness of the recruitment method is periodically evaluated and optimized to realize maximal recruitment efficiency.