Introduction [back to top]
People with asthma seek health care for non-urgent reasons, such as routine review and prescription of usual asthma therapy, or for urgent management of disease exacerbations or ‘attacks’. This chapter presents analyses of data on the use of health-care services by people with asthma. In particular, there is a focus on the application of these data to investigate the nature of exacerbations of asthma at a population level.
Clinicians monitor markers of asthma control to guide management and changes in medication. Well-controlled asthma indicates that the disease is mild or well managed and poor asthma control may indicate poor management. Hence, knowledge of the overall level of asthma control in the population provides some information on the effectiveness of the management of asthma in the community and the need for further efforts in improving asthma management. Most markers of disease control require clinical measures that are not readily available at a population level. However, exacerbations are one marker of poor asthma control that can be measured using urgent health-care utilisation data as a proxy for the occurrence of exacerbations. Therefore, these data can be used to monitor levels of asthma control in the population.
There is empirical support for the interpretation of health-care utilisation as a population-based indicator of the level of control of asthma (Cowie et al. 2001; de Marco et al. 2003; Herjavecz et al. 2003; Vollmer et al. 2002). Factors predisposing to poorly controlled asthma, such as poor knowledge about asthma (Goeman et al. 2004; Radeos et al. 2001), absence of an asthma management plan (Adams et al. 2000; Fernandes et al. 2003; Radeos et al. 2001), poor self-management skills (Kennedy et al. 2003; Soriano et al. 2003) and limited access to primary care (Christakis et al. 2001), are also associated with greater health-care utilisation. Furthermore, interventions that are aimed at improving asthma control through self-management plans and education have been shown to reduce urgent health-care utilisation (Castro et al. 2003; Cote et al. 2001). However, the occurrence of exacerbations does not always indicate the presence of severe or poorly controlled asthma. Viral respiratory tract infections cause disease exacerbations, even in people with otherwise well-controlled asthma (Reddel et al. 1999). Hence, the incidence of exacerbations of asthma is an imperfect marker of the potential for improved control of asthma at a population level.
The nature of the health care is related to the severity of the exacerbation. People with asthma who experience exacerbations of their disease may self-manage the episode or seek urgent medical care from their general practitioner. In more severe cases, they may seek care from a hospital emergency department. There is a relationship between severity of the exacerbation and type of health care used. General practitioners provide the largest volume of care, however this includes maintenance and review care for asthma as well as management of asthma exacerbations. Hospitals are generally only used for the management of exacerbations of asthma, although some people do attend emergency departments for care that could best be described as ’maintenance’. Generally, people with more severe exacerbations require admission to hospital for a period of one or more days. At the most severe end of the spectrum of exacerbations are those associated with acute ventilatory failure, for which mechanical ventilation is required. Hence, there is a spectrum of intensity of health-care interventions, which approximately corresponds to the severity of the exacerbation.
Health-care use attributable to exacerbations of asthma is an indicator, albeit imperfect, of the level of control of asthma in the community. The nature and intensity of health service use gives a further indication of disease control by reflecting the severity of the exacerbations of asthma. In this chapter, we investigate general practice encounters, hospitalisations and emergency department (ED) visits for asthma as well as hospital admissions which required invasive mechanical ventilation. Furthermore, we examine health-care expenditure associated with asthma.
© Australian Institute of Health and Welfare 2008
This work is copyright. Apart from any use as permitted under the Copyright Act 1968, no part may be reproduced without prior written permission from the Australian Institute of Health and Welfare. Requests and enquiries concerning reproduction and rights should be directed to the Head, Media and Publishing, Australian Institute of Health and Welfare, GPO Box 570, Canberra ACT 2601.