Background Overcrowding of emergency departments (EDs) adversely affects the delivery of emergency care and results in increased patient mortality.

Objective and methods To examine what contributes to the ED crowd and to specifically examine the patient associated population. The ED in which the research was performed is consistently one of the most overcrowded in Ireland.

Results On average 66.7% of the patients in the ED during the study period were boarded awaiting a hospital bed following full processing by the ED staff and agreement by the on-call team that admission was required. The most overcrowded part of the department was the majors area. In this area 55.5% of those present were patients, visitors accounted for 16.6% of occupants, nursing staff 11%, on-call teams 7% and the ED doctors 6.3%.

Conclusions Knowing who the people in the crowd are helps to guide management decisions about how the crowd might be reduced. Our department now has a strict accompanying person/visitor policy that limits the number of visitors to patients and limits visiting times for those relatives with a patient who is experiencing a prolonged stay in the ED.