Rapid response systems in hospital settings: an umbrella review

To synthesise review-level evidence on rapid response systems (RRS; encompassing rapid response teams [RRTs], medical emergency teams [METs], and critical care outreach [CCO]), evaluate the effectiveness-implementation gap, and identify multilevel activation barriers, nursing roles, and organisational determinants.

Following PRISMA 2020 and Joanna Briggs Institute umbrella review methodology, five databases were searched to January 2025. Review articles examining RRS in acute care hospitals were eligible. Methodological quality was assessed with A MeaSurement Tool to Assess systematic Reviews 2 (AMSTAR 2); primary-study overlap was quantified via corrected covered area (CCA).

Forty-eight reviews (2006-2025) were included, with publication accelerating in 2021-2025 (37.5%). AMSTAR 2 of 24 systematic reviews yielded high (n = 8), moderate (n = 9), low (n = 4), and critically low (n = 3) confidence. CCA indicated very high overlap (31.0%) among seven traditional meta-analyses, attenuated to 19.5% with an automated-alert meta-analysis. Meta-analyses showed consistent cardiac-arrest reductions (RR 0.60-0.73) and mortality reductions (RR 0.80-0.96; significant in five of eight estimates). Hierarchical interprofessional culture was identified in 14 of 15 barrier-focused reviews (93.3%).

Convergent evidence supports RRS effectiveness, yet persistent multilevel barriers produce a substantial effectiveness-implementation gap. We propose a Multilevel Escalation Failure Model integrating individual, interprofessional, and organisational determinants to guide targeted strategies addressing the structurally paradoxical position of nurses within RRS.

Findings support targeted nursing interventions: simulation-based escalation training, role clarification, policies enabling nurse-initiated activation without mandatory physician endorsement, and multi-component strategies addressing interprofessional power dynamics and culture.