Peer accountability in patient safety: an under-examined determinant of team performance.

BACKGROUND: Patient safety has been pursued largely through systems, protocols and checklists, yet preventable harm remains common and effective interventions are often difficult to sustain or transfer between settings. A consistent observation is that the same intervention succeeds in one unit and fails in another, the difference lying less in the tool than in how the team functions. This review argues that an under-examined determinant of that difference is peer accountability: the lateral, reciprocal responsibility of team members to uphold shared standards and address departures from them. Distinct from vertical, blame-based accountability and related to but not identical with psychological safety and relational coordination, it is treated here as an integrative facet of team functioning rather than a wholly new construct. METHODS: This is a narrative, non-systematic review. Literature in organisational science, human factors, team sport and patient safety was identified through purposive searching of PubMed, Scopus and Google Scholar up to 2025, with citation tracking; material was selected to develop the central argument rather than to provide exhaustive coverage. RESULTS: Across several fields, the maintenance of shared standards by peers is associated with team performance, illustrated by analogy rather than direct evidence by small-group cohesion research and peer leadership in team sport. In healthcare, the same principle underlies crew resource management, the independent check, speaking-up behaviour and high-reliability organising. Two factors suppress peer accountability: steep authority gradients and a misreading of just culture as the absence of accountability. Acting earlier than disciplinary processes, peer accountability can interrupt the gradual normalisation of unsafe practice, which neither punitive blame nor an undifferentiated no-blame stance prevents. CONCLUSION: Peer accountability complements rather than competes with systems thinking. Any hospital service can strengthen it through small, stable, mutually visible teams; institutionalised independent checking; a reduced gradient for raising concerns; and a just culture that retains individual and shared responsibility. These organisational rather than technological measures require explicit measurement and study before they can be recommended as established practice.