Intermedia Agenda-Setting of a Scientific Controversy in the Hybrid Media System: A Cross-Media and Cross-Platform Analysis of Hydroxychloroquine During COVID-19

Existing research on intermedia agenda-setting within the hybrid media system has primarily focused on political communication. This study extends prior work by examining how a scientific controversy circulated across legacy and social media platforms. Specifically, it investigates the debate over hydroxychloroquine (HCQ) as a potential COVID-19 treatment and explores whether, and how, legacy media and social media set each other’s agendas. We conducted a cross-media and cross-platform analysis using data from legacy media (broadcast, cable news, and national newspapers; N = 2,276) and social media (Twitter, N = 416,087; Facebook, N = 28,566). Combining time-series analysis with large language model-assisted framing analysis, the results reveal a complex relationship across platforms: overall, coverage of HCQ did not exhibit consistent agenda-setting effects between legacy and social media. However, framing patterns diverged significantly. Legacy media emphasized Conflict and Public-Risk frames, while social media discourse was dominated by polarized Conflict and Economic-Consequences frames. These findings contribute to the literature on networked agenda-setting in the hybrid media system by providing empirical evidence from science communication, extending the framework beyond its predominant focus on political communication.