Introduction. Frontline nurses who care for trauma-exposed patients face indirect exposure and heightened risk for secondary traumatic stress (STS). STS has been linked to sleep problems and broader functional impairment in Western settings, however, relevant studies in Asian contexts is still limited. Specifically, the mechanisms underlying the STS-sleep relationship remain unclear among Hong Kong nurses.


Purpose. To estimate the strength of the STS-insomnia association in Hong Kong nurses and identify two main mechanisms— emotional distress (psyhological distress) and work functioning (work impairment).


Methods. Hong Kong nurses (N=427) who cared for trauma-exposed patients were recruited to complete an online survey (Dec 2024-Feb 2025). Measures included 20-item Secondary Traumatic Stress Scale(STSS), insomnia (Insomnia Severity Index-3) and two primary mediators— psychological distress and work impairment. Age and gender were included as covaraties.


Results. STS was positively associated with insomnia (β_total = .42, p < .001). Parallel mediation indicated a sizable total indirect effect (β = .30; 95% CI [0.31, 0.58]), carried primarily by psychological distress (β = .23; [0.20, 0.49]) and secondarily by work impairment (β = .07; [0.05, 0.16]). After accounting for mediators and covariates (age, gender), the direct effect remained significant (β_c′ = .12; 95% CI [0.02, 0.34]). The model explained 36% of the variance in insomnia (R² = .36). Covariates showed no significant direct associations with insomnia.


Conclusions. Among Hong Kong nurses caring for trauma-exposed patients, the link between STS and insomnia appears to operate primarily through emotional distress, with additional contributions from work functioning. These pathways can guide targeted sleep interventions for healthcare workers experiencing STS. Future work should test and refine this model in longitudinal or intervention studies.