Characteristics and outcomes of patients who "did not wait" after attending Perth public hospital emergency departments, 2000-2003.

OBJECTIVE: To determine characteristics and outcomes of patients who did not wait to see a doctor in emergency departments (EDs). DESIGN AND
SETTING: Population-based outcome study using probabilistically linked ED and Western Australian death records, with ED records from all seven Perth public hospitals that have EDs from 1 July 2000 to 30 June 2003. MAIN OUTCOME MEASURES: Rates of "did not wait" (DNW) presentations, overall and for individual hospitals; characteristics of DNW patients; mortality rates among DNW patients at 2, 7 and 30 days.
RESULTS: DNW rates varied from 2.6% to 6.3% (average, 4.1%) and were generally lower in tertiary teaching hospitals. DNW patients had conditions of lower urgency, predominantly Australasian Triage Scale category 4 (67.1%) and 5 (23.4%). The DNW rates in these categories were 5.8% and 10.6%, respectively (P < 0.001). Patients referred by health care providers had lower DNW rates (0.5%; P < 0.001). DNW patients were more frequently male (4.4% v 3.8%; P < 0.001), and young to middle-aged adults (15-44 years; 5.8%; P < 0.001). Patients with a higher than average DNW rate were more likely to arrive by private transport (5.0%; P < 0.001) or with police (5.8%; P < 0.001), re-present for review (8.6%; P < 0.001) or have social or behavioural problems (7.7%; P < 0.001). Most patients (91.9%) did not wait on only one occasion. The 30-day mortality rate among DNW patients was significantly lower than for patients seen by a doctor and discharged (0.14 v 0.20%; P = 0.026), and for all patients seen in the ED (1.28%; P < 0.001).
CONCLUSIONS: Patients who did not wait for medical assessment in Perth EDs had conditions of lower acuity and had lower mortality rates than those who waited for assessment.