Gordon Bradley D, Flottemesch Thomas J, Asplin Brent R
Regions Hospital Department of Emergency Medicine, St. Paul, MN, USA.
Ann Emerg Med. 2008 Nov;52(5):504-11. doi: 10.1016/j.annemergmed.2007.11.036. Epub 2008 Mar 7.
Managers use timestamps from computerized tracking systems to evaluate emergency department (ED) processes. This study was designed to determine how accurately these timestamps reflect the actual ED events they purport to represent.
An observer manually timestamped patient and provider movement events during all hours. The observed timestamps were then systematically matched to equivalent timestamps collected by an active tracking system (timestamps created by staff with keyboard/mouse) and a passive tracking system (timestamps created by sensor badge worn by staff members). The deviation intervals between the matched timestamps were analyzed.
The observer noted a total of 901 events; 686 (76%) of these were successfully matched to active system timestamps and 60 (6.7%) were matched to passive system timestamps. For the active system, the median event was recorded 1.8 minutes before it was observed (interquartile range 30.7 minutes before to 2.9 minutes after). Protocol execution difficulties limited the study of the passive system (low number of successfully matched events). The median event was recorded by the passive system 1.1 minutes before it was observed (interquartile range 1.3 minutes before to 0.9 minutes before) (n=60).
The timestamps recorded by both active and passive tracking systems contain systematic errors and nonnormal distributions. The active system had much lower precision than the passive system but similar accuracy when large numbers of active system observations were used. Medians should be used to represent timestamp and interval data for reporting purposes. Site-specific data validation should be performed before use of data in high-profile situations.
管理人员使用计算机化跟踪系统的时间戳来评估急诊科（ED）流程。本研究旨在确定这些时间戳在多大程度上准确反映了它们声称代表的实际ED事件。
一名观察者在所有时间段手动记录患者和医护人员的移动事件时间戳。然后将观察到的时间戳与主动跟踪系统（工作人员通过键盘/鼠标创建的时间戳）和被动跟踪系统（工作人员佩戴的传感器徽章创建的时间戳）收集的等效时间戳进行系统匹配。分析匹配时间戳之间的偏差区间。
观察者共记录了901个事件；其中686个（76%）与主动系统时间戳成功匹配，60个（6.7%）与被动系统时间戳匹配。对于主动系统，事件中位数在观察到之前1.8分钟被记录（四分位间距为观察到之前30.7分钟至观察到之后2.9分钟）。协议执行困难限制了对被动系统的研究（成功匹配事件数量少）。被动系统记录的事件中位数在观察到之前1.1分钟（四分位间距为观察到之前1.3分钟至观察到之前0.9分钟）（n = 60）。
主动和被动跟踪系统记录的时间戳都存在系统误差和非正态分布。主动系统的精度远低于被动系统，但在使用大量主动系统观察数据时准确性相似。在报告时，应使用中位数来表示时间戳和间隔数据。在高关注度情况下使用数据之前，应进行特定地点的数据验证。
