Trauma-Related Symptomatology in Horizontal Nurse-to-Nurse Bullying: An Integrative Review of Direct and Indirect Exposure Pathways.

AIMS: This integrative review synthesized empirical and conceptual literature on horizontal nurse-to-nurse bullying and trauma-related symptomatology, with particular attention to how secondary traumatic stress has been theoretically conceptualized and operationalized in relation to direct versus indirect exposure pathways.

METHODS

Guided by Whittemore and Knafl, an integrative review was conducted. Searches were completed on 6 May 2026 across three databases. Empirical and theoretical studies examining horizontal bullying and trauma-related symptoms in nurses were included. Methodological quality was appraised using Joanna Briggs Institute tools. Data were analyzed using a constant-comparative approach, with reporting aligned to PRISMA 2020.

RESULTS

The literature represented over 3,000 nurses across multiple countries. Four themes emerged: (1) measurement-exposure misalignment, with secondary traumatic stress instruments frequently applied to directly victimized nurses despite the construct's grounding in indirect exposure; (2) aggregation of horizontal bullying within broader workplace violence constructs, limiting relational specificity; (3) under-measurement of witnessing, despite its role as a plausible indirect trauma pathway that may intensify symptoms when combined with direct victimization; and (4) contextual vulnerabilities, particularly among novice and critical care nurses. Common limitations included cross-sectional designs, reliance on self-report, and inconsistent definitions of trauma exposure.

CONCLUSIONS

Horizontal bullying is associated with trauma-consistent symptom patterns, but conceptual and measurement precision remains limited. Distinguishing direct and indirect exposure pathways, explicitly measuring witnessing, and implementing trauma-informed leadership are critical to protecting nurse well-being and supporting patient safety.