Effectiveness of mental health triage systems in reducing psychiatric emergency department admissions

Psychiatric emergency department (PEDs) face significant challenges such as overcrowding, prolonged wait times, and resource constraints, often resulting in suboptimal care. Mental health triage systems have been developed to prioritize urgent cases, optimize resource allocation, and reduce unnecessary admissions, yet their effectiveness remains variably reported. This scoping review aimed to systematically synthesize empirical evidence on the effectiveness of mental health triage systems in reducing psychiatric emergency department admissions and identify factors influencing their success. Following Arksey and O'Malley's framework and PRISMA-ScR guidelines, a comprehensive search was conducted across PubMed, PsycINFO, Scopus, and Web of Science for studies published between 2000 and 2025. Included studies evaluated triage interventions in psychiatric emergency settings with reported outcomes on admission rates. Data were extracted and synthesized narratively. Twenty-three studies from diverse international settings met inclusion criteria. Findings indicate that structured triage systems, particularly nurse-led models employing validated assessment scales, contribute to reductions in avoidable PED admissions. Multi-disciplinary approaches further enhanced decision-making complexity and patient outcomes. Key facilitators included rigorous staff training and integration with community mental health services. Barriers such as inconsistent triage application, limited alternative care options, and staff resistance impeded effectiveness. Mental health triage systems show promise in optimizing psychiatric emergency care by reducing unnecessary admissions and improving prioritization. Their effectiveness depends on standardized protocols, comprehensive training, and strong community linkages. Future research should focus on rigorous, longitudinal evaluations to inform evidence-based triage frameworks.