Delayed discharge, commonly known as ‘bed blocking’, presents a significant and persistent challenge for the NHS. This issue arises when patients that a considered medically fit for discharge, remain hospitalised due to delays in arranging essential social care or community nursing support.     

The consequences are far-reaching, severely straining the availability of acute beds and negatively impacting patient well-being.  According to NHS England data, in February 2024, there were between 13,200 and 14,200 patients remaining in hospital each day who did not meet the criteria to stay. This represents over one in eight general and acute beds in England.    

There are also concerns that the number of people delayed in hospital for more than three weeks has increased.  

The IPACS Project: a collaborative solution 

This issue has been prevalent for several years and to tackle it, the Improving Patient Flow between Acute, Community, and Social Care (IPACS) project was initiated in 2020. This ambitious three-year initiative was funded by Health Data Research UK (HDRUK), an independent, registered charity specialising in health data research that tackles pressing healthcare issues. To deliver the project, a diverse team of experts from the University of Bath, the University of Exeter Medical School, and the Bristol, North Somerset, and South Gloucestershire (BNSSG) Integrated Care Board (ICB) came together.     

The team’s mission was to develop an open-source computer simulation model to analyse patient flow complexities, offering a potential solution for healthcare organisations facing similar challenges with delayed discharges.  

Utilising Operational Research (OR) techniques, which involve applying analytical models to solve complex problems, the team sought to address the intricate factors contributing to these delays. Several team members were highly experienced in OR and affiliated with the Operational Research Society, a professional body dedicated to advancing the field. This project demonstrated the application of OR methodologies to improve healthcare efficiency.

A multidisciplinary team of experts 

The strength of the IPACS project lay in its multidisciplinary team. Dr. Richard Wood and Dr. Paul Forte from NHS BNSSG ICB provided invaluable on-the-ground healthcare expertise and direct access to decision-makers, ensuring the model’s relevance to real-world challenges.  Professor Christos Vasilakis, founding director of the Centre for Healthcare Innovation and Improvement (CHI2), and Dr. Zehra Onen Dumlu at the University of Bath, worked in close collaboration with Professor Martin Pitt and Dr. Alison Harper from the University of Exeter Medical School. Together, they undertook the complex task of modelling, developing, and implementing the simulation framework, bringing academic rigor and practical insight to the project.  

Focusing on the ‘Discharge to Assess’ service 

A key focus of the IPACS project was the seamless transition of patients from acute care to community care, particularly through the ‘Discharge to Assess’ (D2A) service. This service, designed to facilitate efficient patient flow out of acute hospitals, uses three distinct pathways:  The first is Pathway 1 (P1), which focuses on enabling patients to return home with domiciliary visits, promoting independence in familiar surroundings.    

Pathway 2 (P2) provides bed-based rehabilitation for patients requiring more intensive support, aiding recovery, and preventing readmissions.  

Pathway 3 (P3) involves complex care assessments, often leading to care home placements, ensuring appropriate long-term care for vulnerable individuals. The IPACS project aimed to optimise capacity allocation across these critical pathways.  

The BNSSG region: a real-world laboratory 

The Bristol, North Somerset, and South Gloucestershire (BNSSG) region, serving a population of approximately one million, provided a real-world laboratory for the IPACS project. Its diverse demographic mix, encompassing the urban landscape of Bristol, rural North Somerset, and South Gloucestershire, mirrored many of the challenges faced across the UK. The region’s D2A pathways were under immense pressure, with near-full occupancy and significant discharge delays, highlighting the urgent need for innovative solutions and providing invaluable real-world data for the model.

Operational research and simulation modelling 

Professor Vasilakis and Dr Wood identified the core challenge as the complex interplay between acute, community, and social care services.     

Delays in community and social care provision create bottlenecks that ripple through the entire care system, impacting emergency department overcrowding and ambulance delays.  The team began by gathering real-time data on patient occupancy and discharge delays, establishing a baseline and generating “what if” scenarios by varying lengths of stay and arrival rates.    

Central to the IPACS project was the use of computer simulation modelling, a powerful Operational Research technique.     

This approach allowed the team to simulate patient flow through D2A pathways, capturing the intricacies of each stage; testing various intervention scenarios to evaluate their impact; optimising resource allocation to reduce discharge delays; and analysing time-varying demand to account for fluctuations in patient needs. The model incorporated time-varying demand, capacity constraints, and statistical distributions, using the open-source ‘R’ programming language for accessibility and transparency.  

Real-world impact and future directions 

The model’s outputs highlighted the significant impact of strategic changes, particularly achieving target pathway splits and lengths of stay. Notably, model estimates were used to support a £13 million business case for local D2A system development, demonstrating the project’s real-world influence.    While IPACS provides a powerful tool, the team acknowledged its limitations. The model does not encompass all discharge aspects, such as specific social care inputs, palliative care pathways, or post-D2A placements.     

Data completeness also poses challenges. Future research could expand the model to include social care, examine the impact of acute blockages, optimise home-based care, and develop less computationally intensive analytical solutions.     

The ongoing challenge and steps forward 

 As recent data has evidenced, delayed discharge remains a significant issue today. However, the IPACS project represents a big step towards addressing this persistent crisis. By providing a data-driven approach to optimise patient discharge pathways, the team demonstrated the transformative power of Operational Research in healthcare delivery. Through careful analysis and simulation, a more efficient and compassionate healthcare system can be created, ensuring patients receive timely care and restoring dignity.