Exploring the role of flexible use of bed capacity in acute stroke pathways: a computer modelling study

Sound and evidence-based decision making on bed capacity options along patient pathways is essential to avoid pressure building in different parts of the healthcare system, and to help ensure best patient outcomes and financial sustainability. Yet, routine decision support methods typically use only average arrival rate and lengths of stay, which are well known to underestimate the number of beds required. This study investigates the extent to which averages-based estimates can be augmented by a robust assessment of additional ‘flex capacity’ requirements, to be used at times of peak demand. The setting is a major healthcare system in England, which has been working towards a centralised acute stroke pathway. Numerical experiments using an open-source pathway simulation tool recently developed by our team (PathSimR) showed that, to ensure delay for only 1% of presentations at the hyper-acute stroke unit, flex capacity would be needed at 45%, 45% and 36% of the allocated averages-based bed requirement for the hyper-acute, acute and rehabilitation units respectively. Some amount of flex capacity would be required 30%, 20% and 18% of the time. This study demonstrates the importance of appropriately capturing variability within capacity plans, and provides a practical and economical approach which can complement commonly-used averages-based methods. Results of this study have directly informed the healthcare system’s new configuration of stroke services.