Platform-Mediated Identity in Digital Societies: A Quantitative Analysis of Gendered Professional and Personal Expression Among Health Opinion Leaders

Research on social media-based health communication has largely focused on non-credentialed influencers or single platforms, leaving limited empirical insight into how credentialed health professionals negotiate professional and personal identity across platform environments. Addressing this research gap, the present exploratory pilot study examines how health opinion leaders (HOLs)—credentialed health professionals active on social media—express professional and personal identities across Instagram and TikTok, and how these expressions vary by gender. Using a quantitative, multiple-case design, the study analyzes 1237 posts and Stories from four Instagram accounts and two TikTok accounts belonging to Norwegian HOLs. Drawing on theories of platform affordances and identity performativity, the analysis traces content-level patterns in how expertise, authenticity, and engagement are staged within specific platform environments. Rather than offering generalizable platform effects, this study identifies contrasting tendencies within a small set of cases: Instagram content more frequently blends professional and personal narratives—especially among female HOLs—while TikTok content is oriented toward more streamlined, expert-focused presentation. Engagement dynamics further differ across platforms, suggesting that visibility and interaction are shaped by distinct platform logics. This study contributes theoretically by demonstrating that professional identity expression in health communication is platform-conditioned and gendered, extending dramaturgical perspectives to contemporary platform infrastructures. More broadly, this study demonstrates how data-based analysis of digital trace content can illuminate shifting boundaries of expertise and identity within digital societies. Finally, given the emergence of HOLs as a socio-professional phenomenon, these findings serve as a stepping stone for larger-scale research and raise practical concerns about trust, professional boundaries, and the adequacy of existing guidelines in increasingly hybrid professional–personal online practices.