Volume 193 - Issue 1
Myths of ideal hospital occupancy
Authors: David Mountain, Daniel Fatovich and Sally McCarthy
Med J Aust 2010; 193 (1): 61-62. || doi: 10.5694/j.1326-5377.2010.tb03751.x
Published online: 5 July 2010
Published online: 5 July 2010
To the Editor: Many of the arguments put forward by Bain and colleagues about modelling hospital occupancy1 are true in an academic sense. We agree that many acute care models use simplified inputs and outputs, without accounting for rapid daily fluctuations in occupancy. Occupancy definitions are often misleading and subject to gaming. We agree with the work by Bain, Taylor and others that highlights as a problem “the inability to move patients from the [emergency department] to a ward” and that hospitals should “engage procedures to free inpatient beds well in advance” of access block occurring.2 The capacity of a hospital must have flexibility to deal with demand fluctuations.1
However, we do not agree that the “85% occupancy” figure for optimal efficiency is a candidate for myth status. This threshold is used in various systems around the world. Efficiency is a well recognised concept in queuing theory and depends on setting the utilisation (occupancy) rate at a level where the costs of “underutilised” resources (beds, staff not fully used, etc) are shown to acceptably match the “costs” from delayed care (mortality, morbidity, economic, political, prolonged stay, etc). In particular, quoted occupancy figures often look better than reality because of unopened, unusable beds or data manipulation to improve reported occupancy. The more complex and variable the inputs into a system with multiple competing queues (such as hospitals, where acute admissions may be > 70% of the workload), the greater the need for additional capacity to avoid deferred service. Major acute care hospitals show dramatic daily fluctuations in bed use, with changes between low and high occupancy rates in the order of 15%–20%.3 As inputs and variation increase, the likelihood of marked performance deterioration increases exponentially.
Real life (or “clinical modelling”) shows that reported occupancies around or above 85% routinely lead to loss of access to care. No benefits of emergency department or hospital overcrowding have been reported in the medical literature, only harm.4 Relying on developing complex mathematical models before accepting that we are already beyond the acceptable “efficient” occupancy of our current health systems is not a realistic way forward, when patients are dying due to the lack of available appropriate beds.4
Garling, in the overview of his report referred to by Bain and colleagues, states “my recommendations should make more beds available and reduce access block”, but that even with more efficient bed usage “the addition of 350 beds each year” will be required.5 Action is required now and shouldn’t be delayed or subverted by searching for perfect mathematical models. Our hospitals have demonstrably inadequate capacity, resulting in overcrowding with devastating effects. As we have repeatedly stated, it’s all about available beds.
References
- Bain CA, Taylor PG, McDonnell G, Georgiou A. Myths of ideal hospital occupancy. Med J Aust 2010; 192: 42-43. 0_CBBIIGDB
- Au L, Byrnes GB, Bain CA, et al. Predicting overflow in an emergency department. J Management Math 2009; 20: 39-49. 0_CBBDGCBH
- Cooke MW, Black S, Fletcher A, Jennings M. Flows through beds not occupancy. [e-letter in reply to “Total time in English accident and emergency departments is related to bed occupancy”]. Emerg Med J [internet] 2005. Epub 2005 Jan 17. http://emj.bmj.com/content/21/5/575.extract/reply#emermed_el_446 (accessed Mar 2010).
- Richardson DB, Mountain D. Myths versus facts in emergency department overcrowding and hospital access block. Med J Aust 2009; 190: 369-374. 0_CBBCHFJA
- Garling P. Final report of the Special Commission of Inquiry. Acute care services in NSW public hospitals. Overview. Sydney: New South Wales Government, 2008. http://www.lawlink.nsw.gov.au/lawlink/Special_Projects/ll_splprojects.nsf/vwFiles/E_Overview.pdf/$file/E_Overview.pdf (accessed May 2010, link no longer available). 0_CBBGEJED