The use of acute care hospitals is a significant factor in the increasing cost of health care in many developed countries. The modelling of hospital beds should lead to better decision-making in relation to this expensive resource. The average length of stay is inappropriate for such modelling. Millard and others have shown that compartmental models can be used for bed modelling. These models are plausible and easily interpreted. Little work in relation to generalization and predictability has been undertaken. The purpose of this paper was to consider which methodology is likely to provide the best predictive decision-making in relation to hospital bed use for medical patients based upon the work of Millard and his colleagues. Our results showed that the annual average model performed best and offers a superior predictive capability over one-day census models. Model creation should be based upon the consideration of as many points as necessary to capture the variation within the data. Improvement in model performance may be obtained by the creation of more complex models. Consideration about the method of optimisation used to create the models is also required to ensure that it coincides with the goals of the users.
Keywords: hospital beds, occupancy, length of stay, modelling, prediction The Authors:
Mark Mackay BSc(Hons) BEc BComm
PhD Candidate, Department of Psychology
University of Adelaide
Principal Project Officer
Department of Human Services
Ph: 61 8 8463 6130
Fax: 61 8 8226 8910
Dr Michael Lee BSc(Ma) BA(Hons) Grad Dip Ed PhD
Department of Psychology
University of Adelaide
Ph: 61 8 8303 6096
Fax: 61 8 8303 3770
Compartmental models of hospital bed occupancy and choice of data Introduction
In recent years the Australian public health sector has seen increasing pressure to do more with the same or reduced levels of expenditure. At the same time, the number of beds in public acute care hospitals has been declining, while the level of demand and patient expectation is increasing. Consequently, the provision of public health care has become a political risk, often with debate not progressing beyond the number of hospital beds provided by the different political parties.
The percentage of the gross domestic product expended on the health sector in Australia has increased since 1972. While there was a slight reduction in the level of expenditure as a percentage of GDP during the early to mid 1980s, growth has continued during the 1990s, as shown in Table 1. This phenomenon, however, is not unique to Australia, but has occurred across countries with which Australia is often compared in relation to health care, such as the United States of America, the United Kingdom and New Zealand. Table 1: Health Expenditure Trends in Australia, New Zealand, United Kingdom and the United States of America. Based upon OECD data 2001.
During the same time, the percentage of expenditure that relates to provision of public health care services in Australia has grown. Similar growth has occurred in the USA, but not in New Zealand or the United Kingdom.
It is widely acknowledged in journals and numerous reviews (e.g., Generational Health Review, 2003; Barclay, 2003) that, particularly in view of the ageing society, which is likely to result in increased demand for services, workforce issues and rising costs, the current level of health care provision is not sustainable.
1972 1977 1982 1987 1992 1998
Australia 5.7 7.5 7.3 7.4 8.2 8.5
New Zealand 5.3 6.6 6.1 5.9 7.6 8.1
United Kingdom 4.7 5.4 5.8 6 6.9 6.7
United States of America 7.3 8.4 10 10.9 13.6 13.6
Australia 62.1 61.6 60.3 69.6 66.9 69.5
New Zealand 77.3 76.3 88 87.2 79 77.1
United Kingdom 87.8 90 87.6 84.9 85.3 83.7
United States of America 37.2 40 40.7 40.5...