A review of social media methods and lessons learned from the National Children's Study.

Introduction: Given the reach and influence of social media, the National Children's Study Vanguard Study evaluated the feasibility, acceptability, and cost of using social media to support participant retention.

Methods: We describe a social media experiment designed to assess the impact of social media on participant retention, discuss several key considerations for integrating social media into longitudinal research, and review factors that may influence engagement in research-related social media.

Results: User participation varied but was most active when at launch.