Sustainability of performance improvements after 26 Kaizen events in a large academic hospital system : a mixed methods study

INTRODUCTION: Implementing Kaizen can improve productivity in healthcare but maintaining long-term results has proven challenging. This study aimed to assess improved performance achieved and sustained by Kaizen events and find explanatory factors for the persistence or decline of long-term results. METHODS: Kaizen events were conducted in 26 specialised healthcare units in a large academic hospital system in southern Finland. Primary data for mixed methods analysis was collected from each unit with 21 semi-structured interviews, Kaizen report files and performance metrics. RESULTS: Fifteen explanatory factors were found in this study. Work culture and motivation for continuous improvement stood out as the most important explanatory factor for the persistence of long-term results-lack of time for improvement activities and high workload for the decline. Success in preparation and follow-up was associated with sustained long-term results. Thirteen units achieved long-term results, three units could not sustain the performance improvements and five units struggled to make any improvements. CONCLUSIONS: This study explains the long-term sustainability of performance improvements, bringing new insights to Kaizen research. Our findings can guide organising successful Kaizen events. The events can be worth organising even though long-term performance improvements are not guaranteed. Units with supportive working culture and motivation for the Kaizen event will likely succeed. A unit should aim to create a supportive foundation for Kaizen before organising a Kaizen event. Units that lack the foundation can be identified, trained and guided to increase their chances of success. Pitfalls like high workload and insufficient follow-up should be proactively identified and appropriately managed by allocating the required time and resources for the development work.Peer reviewe