Sustainability of Lean interventions in public hospitals after a national quality improvement programme: a multicentre mixed-methods study

Objectives: To evaluate the sustainability of Lean Healthcare practices after the implementation phase of a national quality improvement programme and to identify organisational factors associated with maintaining results over time. Design: Multicentre cross-sectional study with a mixed-methods approach. Setting: Twelve public and philanthropic hospitals in Brazil participating in Phase 2 of the Lean in Emergency Departments Project. Participants: Key respondents in managerial or leadership roles from participating hospitals (response rate: 75.0%). Outcome measures: Sustainability of Lean practices and organisational readiness, assessed through a structured survey and triangulated with operational indicators collected across successive implementation cycles at hospital level. Results: During one year of structured follow-up, 66.7% of respondents reported maintenance of Lean practices; this decreased to 33.3% after the end of structured follow-up. Although 66.7% considered professionals capable of maintaining results, only 58.3% positively evaluated institutional structure, indicating a discrepancy between individual capacity and organisational readiness. Operational indicators showed heterogeneous behaviour across hospitals, with no consistent pattern of sustained improvement. Qualitative analysis identified professional and managerial turnover, formal governance structures, and continuous monitoring as key factors associated with sustainability. Conclusions: The sustainability of Lean Healthcare practices is more strongly associated with institutional capacity to embed and sustain changes over time than with isolated individual training. Quality improvement programmes should incorporate structured strategies for the post-implementation phase. Keywords: Lean Healthcare; Sustainability; Quality improvement; Hospital flow; Health systems; Organisational factors