Understanding the current state of patient flow in a hospital.

The challenge of generating bed availability is constant in most NHS acute trusts. Building on previous work applying queue theory, this paper now takes operational data from one NHS trust, collected over a period of more than a year, to provide an evidence base and to establish the practical challenges associated with demand variation and managing length of stay. The problem is split into three separate parts. Daily bed shortages are mostly influenced by the timing of arrival and discharge of patients with a short length of stay. Patients who stay for longer than one to two days contribute most significantly to the observed weekly bed availability problem. The problems associated with bed shortages around Christmas time and into the New Year are not simply issues of increased demand. A reduction in discharge capacity is a major contributory factor that results in unnecessary increases in length of stay.