Spill Over Effects of Inpatient Bed Capacity on Accident and Emergency Performance in England.

The English National Health Service (NHS) has failed to meet the four-hour waiting time target to admit, transfer or discharge 95 per cent of patients attending Accident and Emergency Departments (A&E) since 2013. A growing number of patients requiring inpatient care are waiting on trolleys longer than four hours before admission to a hospital bed. This study examines the role of bed occupancy in the deterioration of A&E performance in the NHS. Longitudinal panel data methods are used to analyse hospital data (n = 72,129,886) for 143 Trusts from 1st June 2016 to 31st October 2019. The average bed occupancy rate across the study period was 93.2%. A 1% increase in bed occupancy was associated with a 9.5 percentage point decrease in the Trusts' probabilitay of meeting the waiting target, and an approximately 6 patient increase in four hours to 12 -hs trolley waits per 1,000 admissions. These relationships became more pronounced with rising bed occupancy levels above a 90% threshold. Bed occupancy is associated with significant negative spill-over effects on A&E performance. We estimate a minimum investment in 3,861 additional inpatient beds across the NHS to improve A&E performance in England. Relevant lessons can be derived for health care systems that have observed similar trends in increasing bed occupancy and deteriorations in A&E performance, including Ireland, Canada and Israel.