A Model to Assist Planning the Provision of Hospital Services

One of the most important health service issues concerns the level of provision of acute hospital beds. To assist resolution of this issue, a model is proposed which simulates how hospital beds are used in terms of admission rates and lengths of stay for different categories of disease. The model can be used to predict the likely effects of changes in the provision of beds. Thus if it is proposed to increase the supply of beds the model will estimate, by disease type, how much of an increase this will cause in admission rates and lengths of stay. The ability of the model to accurately simulate this type of behavior is illustrated by an application in Quebec Province, Canada

Modeling Health Care Systems

The biomedical task at IIASA is part of the Research Area, Human Settlements and Services. The aim of the task is to build a national health care system model and to arrange for it to be applied at national centers so as to assist decision makers there. The proceedings of this workshop represent part of the continuing efforts in international cooperation with research institutes involved in health care modelling. It relates the IIASA experience in this field, national efforts, and suggests future needs for health care modelling

Dram Balances Care

In many developed countries the problem of allocating resources within the Health Care System is perennial. Health Care planners wish to know the consequences of changing the mix of resources. The Balance of Care (BOC) Model, designed to help Health Care Planners answer this question, has been successfully applied over the past few years in the Department of Health and Social Security, UK. The Disaggregated Resource Allocation Model (DRAM), developed at IIASA, is also designed to help Health Care planners answer the above question. This paper compares the performance of both models in two respects. Firstly, it indicates that DRAM is likely to be able to cope with problems of the same size and complexity as the BOC model. Secondly, the paper demonstrates that DRAM can more accurately model the use of alternative modes of care within treatment categories. Data collected for the allocation of care for the elderly in Devon, UK are used in the comparisons

A Disaggregated Health Care Resource Allocation Model

The planning of health services can be viewed as occurring in two stages--the estimation of the amounts of health care resources that would be needed if the Health Care System (HCS) were to test all sick individuals at clinically desirable standards, and the downward revision of these estimates in order to comply with economic constraints. To assist in the second stage a model is proposed which includes sub-models for population, disease prevalence, resource supply, and resource allocation and which could be used interactively by the planner to explore resource options. The role of the resource allocation sub-model in this design is to simulate how the HCS allocates limited resources between competing demands. To perform this role a sub-model is proposed which derives from a resource allocation model which is being used in health service planning in the UK. The sub-model as proposed here can be applied to only one sector of the HCS at a time whereas the UK model can be applied to several sectors simultaneously. However, it is more easy to use than the UK model and its computational requirements are considerably lighter. The sub-model is described in terms of its application to the hospital in-patient sector and its performance is illustrated by a hypothetical application to the South Western Region of England

The IIASA Health Care Resource Allocation Sub-Model: Mark 1

Within the context of the IIASA Health Care System model the function of the resource allocation sub-model is to simulate how the HCS allocates limited supplies of resources between competing demands. The principal outputs of the sub-model should be the numbers of patients treated,in different categories, and the modes and standards of treatments they receive. The Mark 1 version of the sub-model is described in this paper. It simulates the allocation of one resource within one mode of treatment but it should be possible to use the approach to develop further versions to cover more general cases. The main assumption of the model is that in allocating its resources the HCS attempts to optimise a utility function whose parameters can be inferred from data on past allocations. Depending upon the type of data that is available different procedures for parameter estimation are required. The procedures for parameter estimation can be incorporated with the algorithm for solving the model into a computer programme whose main inputs consist solely of empirical data. The programme is fairly small and can readily be installed on most scientific computer installations. The use of the sub-model is illustrated by a hypothetical application using hospital data from England

Health Care Resource Allocation Models - A Critical Review

The purpose of a resource allocation sub-model, within the IIASA National Health Care System (HCS) model, is to represent the interaction between the demand for and the supply of health care resources. The overall model can then be used to examine the consequences of alternative health care policies, particularly policies concerned with the production of new resources. The HCS resource allocation models in the literature can be classified into three types: macro-econometric, behavior simulation, and system optimization. For each type some examples are described and the strengths and weaknesses of the approach are assessed. The macro-econometric approach has many advantages; it is well-tried and has standard methods, terminology, and computer programs. But it has the important limitation that its results are only strictly valid over the ranges of the variables that exist in the data from which the econometric equations are estimated. Thus the domain of its valid application is normally limited to small variations around the status quo. By contrast, the behavior simulation approach lacks many of the advantages of the macro-econometric approach but is, in principle, capable of exploring a wider range of situations; provided that the behavioral hypotheses are sound, such a model can be used to explore situations which are radically different from the status quo and in which variables may lie outside the ranges observed to date. In theory the optimization approach produces the ideal solution but in practice, if applied to the HCS, the approach is likely to founder on the difficulty of defining an objective function that both expresses reasonable objectives for the HCS as a whole and, at the same time, takes adequate account of the practice of the actors in the HCS. Accordingly the behavior simulation approach is recommended for the IIASA Task

Computer programs for the IIASA health care resource allocation sub-model, MARK 1- a user's guide

the functions of the different files used in running DRAM Mark 1 are described. the definitions of the variables used int he programs are listed in a dictionary. Flow diagrams and listings of the programs are displayed. Some guidance is given on suitable values for the input date. Input and output for some illustrative runs of the programs are displayed. finally a description is given of the error messages that ca be encountered and appropriate remedial action is presented

Use of A Collagen/Elastin Matrix As Transport Carrier System to Transfer Proliferating Epidermal Cells to Human Dermis in Vitro

This in vitro study describes a novel cell culture, transport, and transfer protocol that may be highly suitable for delivering cultured proliferating keratinocytes and melanocytes to large open skin wounds (e.g., burns). We have taken into account previous limitations identified using other keratinocyte transfer techniques, such as regulatory issues, stability of keratinocytes during transport (single cell suspensions undergo terminal differentiation), ease of handling during application, and the degree of epidermal blistering resulting after transplantation (both related to transplanting keratinocyte sheets). Large numbers of proliferating epidermal cells (EC) (keratinocytes and melanocytes) were generated within 10-14 days and seeded onto a three-dimensional matrix composed of elastin and collagen types I, III, and V (Matriderm®), which enabled easy and stable transport of the EC for up to 24 h under ambient conditions. All culture conditions were in accordance with the regulations set by the Dutch Central Committee on Research Involving Human Subjects (CCMO). As an in vitro model system for clinical in vivo transfer, the EC were then transferred from Matriderm onto human acellular dermis during a period of 3 days. After transfer the EC maintained the ability to regenerate into a fully differentiated epidermis containing melanocytes on the human dermis. Proliferating keratinocytes were located in the basal layer and keratin-10 expression was located in differentiating suprabasal layers similar to that found in human epidermis. No blistering was observed (separation of the epidermis from the basement membrane). Keratin-6 expression was strongly upregulated in the regenerating epidermis similar to normal wound healing. In summary, we show that EC-Matriderm contains viable, metabolically active keratinocytes and melanocytes cultured in a manner that permits easy transportation and contains epidermal cells with the potential to form a pigmented reconstructed epidermis. This in vitro study has produced a robust protocol that is ready for clinical studies in the future

Drainage behavior of sports pitches–A case study review

The drainage behavior of sports pitches has traditionally been designed from experience with hydraulic performance rarely measured in detail. Within the wider industry and regulatory bodies there is a perception that storm water and increased drainage rates from sports pitches contribute to local flood risk. Empirical observations have suggested that in reality pitch drainage systems may discharge water at low volumes and rates and there is often limited surface run-off. Furthermore it appears that lack of technical guidance on the discharge of water from sport pitch drainage systems may have led to misunderstanding their drainage behavior and possible benefits they could bring to water management as opposed to perceived dis-benefits. This paper summarizes selected results of a case study which included field measurements of weather and discharge behavior on a range of natural turf sports pitches in England. The findings from this study indicate that natural turf sports pitches can provide resistance to flow and hence advantageous attenuation of rainfall and storm water. Additionally sports pitches can store large volumes of water within the pervious materials used in their design. The study has confirmed that sport pitches demonstrate the key functions that are reflected in the design requirements of Sustainable Urban Drainage Systems (SuDs) such as pervious pavements providing source control of surface rain water