Abstract

In hospitals, Step Down Units (SDUs) provide an intermediate level of care between the Intensive Care Units (ICUs) and the general medical-surgical wards. Because SDUs are less richly staffed than ICUs, they are less costly to operate; however, they also are unable to provide the level of care required by the sickest patients. There is an ongoing debate in the medical community as to whether and how SDUs should be used. On one hand, an SDU alleviates ICU congestion by providing a safe environment for post-ICU patients before they are stable enough to be transferred to the general wards. On the other hand, an SDU can take capacity away from the already over-congested ICU. In this work, we propose a queueing model of patient flow through the ICU and SDU in order to determine when an SDU is needed and what size it should be. Using first and second order analysis, we examine the tradeoff between reserving capacity in the ICU for the most critical patients versus gaining additional capacity achieved by allocating nurses to the SDU due to the lower staffing requirement. Despite the complex patient flow dynamics, we leverage a dimensionality reduction result in our analysis to establish the optimal allocation of nurses to units. We find that under some circumstances the optimal size of the SDU is zero, while in other cases, having a sizable SDU may be beneficial. The insights from our work provide rigorous justification for the variation in SDU use seen in practice.

Download PDF

Citation

Chan, Carri, Mor Armony, and Bo Zhu. "Critical care in hospitals: When to introduce a Step Down Unit?" Columbia Business School, 2016.

Each author name for a Columbia Business School faculty member is linked to a faculty research page, which lists additional publications by that faculty member.

Each topic is linked to an index of publications on that topic.