Access block and overcrowding in emergency departments: an empirical analysis

To quantify the determinants of the duration of time spent in an emergency department (ED) for patients who need admission to hospital.

A retrospective analysis of a year of administrative data on all patients presenting to 38 public hospital EDs in Victoria, Australia in 2005/2006. Individual administrative data on patient care time, defined as the time in the ED from first being seen by a treating doctor to admission, were analysed using parametric survival analysis (generalised gamma model). Patient times were regarded as censored if the patients died in the ED or were transferred to another hospital. The outcome measure was the elasticity of patient care time, calculated as the percentage change in time for a 1% change in continuous variables and a unit change in dichotomous variables.

The mean patient care time was 396 min (95% CI 395 to 398). Reduced time in ED was associated with the number of nurses (elasticity=-2.38%; 95% CI -2.31 to -2.45); the number of beds (elasticity= -2.99%; 95% CI, -2.89 to -3.08); the number of doctors (elasticity=-0.235%; 95% CI -0.232 to -0.237). There was significant variation in the time spent in the ED across hospitals after adjustment for observable differences in patient and hospital characteristics. Overall an increase in hospital resources, as measured by the number of nurses, doctors and physical beds, is associated with a significant reduction in patient care time in the ED.

Increasing hospital capacity is likely to reduce overcrowding in the average ED, but factors that determine congestion in individual hospitals need to be further investigated.