Proceedings of the 2014 Winter Simulation Conference
A. Tolk, S. Y. Diallo, I. O. Ryzhov, L. Yilmaz, S. Buckley, and J. A. Miller, eds.
THE IMPACT OF HOURLY DISCHARGE RATES AND PRIORITIZATION ON TIMELY
ACCESS TO INPATIENT BEDS
Asli Ozen Patricia Samra
Hari Balasubramanian Mike Ehresman
Haiping Li
Todd Fairman
Joan Roche
University of Massachusetts, Amherst Baystate Medical Center
160 Governors Drive 759 Chestnut Street
Amherst, MA 01002, USA Springfield, MA 01199, USA
ABSTRACT
We develop an empirically calibrated hospital-wide simulation model to represent a time-varying, multiserver
queuing network with multiple patient classes. The focus is on quantifying the impact of discharge profiles
to alleviate inpatient bed congestions. A discharge profile is defined by (a) discharge window, which
specifies hours of the day discharges are allowed; and (b) the maximum capacity for discharges in each
hour of the window. Results of our simulation model show that a more responsive policy that prioritizes
discharges in units with longer admission queues can significantly reduce waiting times (40% reduction
in queues). In comparison, an early in the day discharge policy has a lower impact on improving bed
congestions; we also find that early in the day discharges are very hard to realize in practice. Further,
expanding the discharge windows by only 2 hours in the evening (7-9 PM) creates the same benefit, and
is more realistic.
1 INTRODUCTION
Inability to satisfy bed requests in a timely manner causes hospital wide congestions. These effects include
but are not limited to: patients waiting long hours in the ED or a surgical area for an inpatient bed; patients
not being placed in their primary unit (i.e. off-service placement); urgent patients bumping less critically
sick patients from ICUs to “step-down units”; and refusing transfers from other hospitals.
In this paper, we use an empirically calibrated hospital-wide simulation model to quantify the impact
of discharge profiles on timely access to inpatient beds. We define a discharge profile by (a) discharge
window, which specifies the hours of the day discharges are allowed; and (b) maximum discharges a hospital
can manage in each hour of the window. The discharge process is typically complex and involves many
moving parts; it requires the timing of physician rounds; availability of nurses, case managers and social
workers; and coordination with families and post-hospitalization facilities to all come together. Rather
than considering these individual aspects, which are quite difficult to estimate, we instead use discharge
profiles to model the hospital’s aggregate hourly capacity. Timely access in our model is measured by the
average number of patients waiting for an inpatient bed (average queue length) in any hour. This queue
size includes all patients waiting in the Emergency Department (ED), Post-Acute Care Unit (PACU) or
other locations after the physician has made a request for an inpatient bed.
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