Chepenik Lara, Pinker Edieal
Dr. Chepenik is with the Department of Psychiatry and the Department of Emergency Medicine and Dr. Pinker is with the School of Management, Yale University, New Haven, Connecticut (e-mail:
Psychiatr Serv. 2017 May 1;68(5):470-475. doi: 10.1176/appi.ps.201600202. Epub 2017 Jan 3.
The study illustrates the use of approaches based on queuing theory to understand bottlenecks in patient flow. A queuing simulation was used to predict the potential benefits of additional clinical personnel on patient flow through a psychiatric emergency service (PES).
A discrete-event simulation model was calibrated on the basis of two months of data collected in a PES. This model examined the effects of adding between .5 (half-time) and three additional providers to the 8 a.m. to 4 p.m. shift.
The model showed that an addition of a half-time clinician produced the biggest change in patient flow metrics. Average length of stay was predicted to drop from 38.1 hours to 33.2 hours for patients who were awaiting hospitalization and from 13.7 to 9.0 hours for patients who were eventually discharged. The number of patients waiting to see a provider decreased by two-thirds between 8 a.m. and 4 p.m., and it decreased by one-half during the rest of the day, even though the number of clinical staff remained the same. Adding more providers failed to reduce these numbers much further. Adding more than a half-time provider also failed to significantly reduce boarding (remaining in the PES while awaiting hospitalization).
Queuing simulation predicted a dramatic benefit to patient flow with a fairly small addition in clinician time, a benefit that persisted beyond the time during which the additional staff was on duty, especially when this staff was added during a period of high demand.
本研究阐述了运用基于排队论的方法来理解患者流程中的瓶颈问题。采用排队模拟来预测增加临床人员对通过精神科急诊服务（PES）的患者流程可能产生的益处。
基于在一个PES收集的两个月数据校准了一个离散事件模拟模型。该模型研究了在上午8点至下午4点的班次增加0.5个（兼职）至3名额外医护人员的影响。
该模型显示，增加一名兼职临床医生对患者流程指标产生了最大变化。预计等待住院的患者平均住院时间将从38.1小时降至33.2小时，最终出院的患者平均住院时间将从13.7小时降至9.0小时。上午8点至下午4点之间等待看诊的患者数量减少了三分之二，当天其余时间减少了一半，尽管临床工作人员数量保持不变。增加更多医护人员未能进一步大幅降低这些数字。增加超过一名兼职医护人员也未能显著减少滞留（在等待住院期间留在PES）情况。
排队模拟预测，在临床医生工作时间增加相当少的情况下，对患者流程有显著益处，这种益处会持续到额外工作人员值班时间之后，尤其是在需求高峰期增加工作人员时。
