Principal Investigators' Perceptions on Factors Associated with Successful Recruitment in Clinical Trials.

Participant recruitment continues to be a challenge to the success of randomized controlled trials, resulting in increased costs, extended trial timelines and delayed treatment availability. Literature provides evidence that study design features (e.g., trial phase, study site involvement) and trial sponsor are significantly associated with recruitment success. Principal investigators oversee the conduct of clinical trials, including recruitment. Through a cross-sectional survey and a thematic analysis of free-text responses, we assessed the perceptions of sixteen principal investigators regarding success factors for participant recruitment. Study site involvement and funding source do not necessarily make recruitment easier or more challenging from the perspective of the principal investigators. The most commonly used recruitment strategies are also the most effort inefficient (e.g., in-person recruitment, reviewing the electronic medical records for prescreening). Finally, we recommended actionable steps, such as improving staff support and leveraging informatics-driven approaches, to allow clinical researchers to enhance participant recruitment.