RT Journal Article SR Electronic T1 Access block causes emergency department overcrowding and ambulance diversion in Perth, Western Australia JF Emergency Medicine Journal JO Emerg Med J FD BMJ Publishing Group Ltd and the British Association for Accident & Emergency Medicine SP 351 OP 354 DO 10.1136/emj.2004.018002 VO 22 IS 5 A1 D M Fatovich A1 Y Nagree A1 P Sprivulis YR 2005 UL http://emj.bmj.com/content/22/5/351.abstract AB Objective: Access block refers to the situation where patients in the emergency department (ED) requiring inpatient care are unable to gain access to appropriate hospital beds within a reasonable time frame. We systematically evaluated the relationship between access block, ED overcrowding, ambulance diversion, and ED activity. Methods: This was a retrospective analysis of data from the Emergency Department Information System for the three major central metropolitan EDs in Perth, Western Australia, for the calendar years 2001–2. Bivariate analyses were performed in order to study the relationship between a range of emergency department workload variables, including access block (>8 hour total ED stay for admitted patients), ambulance diversion, ED overcrowding, and ED waiting times. Results: We studied 259 580 ED attendances. Total diversion hours increased 74% from 3.39 hours/day in 2001 to 5.90 hours/day in 2002. ED overcrowding (r = 0.96; 95% confidence interval (CI) 0.91 to 0.98), ambulance diversion (r = 0.75; 95% CI 0.49 to 0.88), and ED waiting times for care (r = 0.83; 95% CI 0.65 to 0.93) were strongly correlated with high levels of ED occupancy by access blocked patients. Total attendances, admissions, discharges, and low acuity patient attendances were not associated with ambulance diversion. Conclusion: Reducing access block should be the highest priority in allocating resources to reduce ED overcrowding. This would result in reduced overcrowding, reduced ambulance diversion, and improved ED waiting times. Improving hospital inpatient flow, which would directly reduce access block, is most likely to achieve this.