When patients present at EDs, they are assigned a triage category, which indicates how urgently they should be treated. Scores on the Australian Triage Scale (ATS) range from 1 (immediately life-threatening) to 5 (less urgent).
Although designed as a measure of clinical urgency, this is now used as a performance indicator for EDs, with the percentage of patients treated within national benchmark waiting times for each triage category compared across jurisdictions.
In order to determine if there were any real differences in ED waiting times across Australia, the researchers analysed data on ED presentations in public hospitals between 1 July 2009 and 30 June 2010 and discussed the results with a national stakeholder workshop.
Associate Professor Green and her colleagues found that, as expected, ED waiting times varied by triage category. Triage category 1 patients were seen the fastest, with patients in triage category 5 waiting the longest.
Using the raw data and with all triage categories combined, the shortest waiting time was in NSW, with an average of 38.5 minutes and the longest in the ACT, with an average of 65.7 minutes. When category 2 and 3 were examined separately, the ACT had the shortest waiting time by far, with an average of 7.5 minutes for patients in triage category 2.
However, there were also jurisdictional differences in other factors. The key finding of the study was that there were no consistent differences in ED waiting times between the jurisdictions after these other factors were taken into account in the analysis. There were, however, jurisdictional differences in the way triage was assessed.
According to the researchers, "no clear effect of socioeconomic status or indigenous status on waiting times was observed. There were small differences by age, with slightly shorter waiting times for adults as age increased and for children."
The lesson highlighted by researchers in this study is "raw waiting time statistics can be misleading. Although one jurisdiction may appear to be the best performer when measured by raw waiting times, this is not the case when differences in the mix of patients and the mix of hospitals are taken into account.
"In the context of current health reform agenda, further research is required to better understand the reasons for differences in triage practices.
"Subsequent to that, a national strategy is required to improve the consistency of triage assignment across the country. Until this occurs, we urge caution in interpreting raw triage waiting times as measures of performance."
"The comparison of hospital performance data must always be undertaken with caution due to variability in the data collection and reporting processes and differences in the patient mix," said Australian Healthcare & Hospitals Association chief executive, Alison Verhoeven.
"For emergency departments many of the factors influencing demand and waiting times arise outside of the emergency department due to high occupancy of in-patient services and availability of community-based primary care services. These external factors must also be considered when evaluating emergency department performance."
