Hospital’s instability wedges

ABSTRACT

In this study, we define a hospital congestion episode as a situation where the number of new patients needing admission is greater than the number of available beds in the hospital, and investigate the likelihood that the current day’s midnight occupancy will exceed any specified threshold level. We demonstrate that this measure of risk exhibits a characteristic sensitivity phenomenon that we have named as hospital’s instability wedge. In particular, it is seen that frequently even small changes in the numbers of patients admitted or discharged can dramatically change the risk of exceeding the threshold, thereby changing the risk of subsequent congestion episodes. While this finding captures a salient difficulty of operating a modern public hospital, it also opens up an opportunity for monitoring and alleviating the above defined risk with only small changes in admission, discharge, and cancellation rates. A case study with recent patient journey data from Flinders Medical Centre in South Australia is presented.

KEYWORDS:

• Hospital congestion
• risk
• hospital capacity planning
• instability

Acknowledgments

This work was supported by the ARC linkage grant LP130100323, jointly awarded to Flinders University, the Southern Adelaide Health Service (Flinders Medical Centre) and the Central Adelaide Local Health Network (Royal Adelaide Hospital). The authors thank Professor Leonid Churilov for his advice on presenting these results to the healthcare research community. They are also grateful to editors and referees for their constructive comments which further helped improve this paper.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Australian Research Council [LP130100323].