A 2-round Delphi survey was conducted from February 2005 to April 2005, with a multi-disciplinary group of 38 Canadian experts in various aspects of ED operations who rated the relevance of 36 measures and ranked their relative importance as indicators of ED overcrowding.
The response rates for the first and second rounds were 84% and 87%, respectively. The most important indicator identified by the experts was the percentage of the ED occupied by in-patients (mean on a 7-point Likert-type scale 6.53, standard deviation [SD] 0.80). The other 9 indicators, in order of the importance attributed, were the total number of ED patients (mean 6.35, SD 0.75), the total time in the ED (mean 6.16, SD 1.04), the percentage of time that the ED was at or above capacity (mean 6.16, SD 1.08), the overall bed occupancy (mean 6.19, SD 0.93), the time from bed request to bed assignment (mean 6.06, SD 1.08), the time from triage to care (mean 5.84, SD 1.08) the physician satisfaction (mean 5.84, SD 1.22), the time from bed availability to ward transfer (mean 5.53, SD 1.72) and the number of staffed acute care beds (mean 5.53, SD 1.57).
Ten clinically important measures were prioritized by the participants as relevant indicators of ED overcrowding. Indicators derived from consensus techniques have face validity, but their metric properties must be tested to ensure their effectiveness for identifying ED overcrowding in different settings.