What can emergency medicine learn from kinetics: Introducing an alternative evaluation and a universal criterion standard for emergency department performance

This research focuses on developing an improved and robust measurement for emergency department (ED) performance and a criterion standard for global use via kinetic analysis. Based on kinetic approach, the input-throughput-output conceptual model of ED crowding is compared to the procedure of enzyme catalysis. All in average, the retented patients in EDs are defined as substrate (S), whereas the patients who depart the EDs as product (P). Therefore, the average ED departure velocity (V) can be presented as P divided by a given time (t) of the ED length of stay (LOS). The S-V and S 2-V plots are depicted hourly for the kinetic analysis. The long-term stability of the kinetic parameters is ascertained by the method of coefficient of variation (CV). The participants collected for this study are from the EDs of Changhua Christian Medical Center and the five branched hospitals, all located in Taiwan. Based on the S-V plot analysis, the results clearly show 2 curves, an upper and a lower curve. The timeline of the lower curve includes approximately the total ED busy hours, and thus it can be used for the subsequent kinetic analysis. In order to explore the adequate kinetic parameters for ED performance, the try-and-error process was followed in this study. As a result, the S²-V plots adapted from the lower curves show the best linear regression of S² on V with a good coefficient of determination (R²). The Pan-Wen constant (PW),which is the slope of the liner regression line, and the ED medical personnel unit turnover number (EDMPU TON) were deduced from the kinetic meanings of S²-Vplots. In this research, the 2 kinetic parameters, PWand EDMPU TON were applied for the ED performance evaluations. An innovative relationship between the ED retented patients and the ED departure velocity is verified asPW;whereas, a feasible kinetic parameter, theEDMPUTONexplicates the teamwork efficiency of theEDproviders.Moreover, theEDMPUTON may not only be a reliable universal criterion standard for the ED performance, but also a valuable reference for both ED providers and payers.