[Tuncated abstract] This research thesis consists of five sections. Section one provides the background information (chapter 1) and a description of characteristics of the cohort and the methods of analysis (chapter 2). The Acute Physiology and Chronic Health Evaluation (APACHE) II scoring system is one of commonly used severity of illness scoring systems in many intensive care units (ICUs). Section two of this thesis includes an assessment of the performance of the APACHE II scoring system in an Australian context. First, the performance of the APACHE II scoring system in predicting hospital mortality of critically ill patients in an ICU of a tertiary university teaching hospital in Western Australia was assessed (Chapter 3). Second, a simple modification of the traditional APACHE II scoring system, the 'admission APACHE II scoring system', generated by replacing the worst first 24-hour data by the ICU admission physiological and laboratory data was assessed (Chapter 3). Indigenous and Aboriginal Australians constitute a significant proportion of the population in Western Australia (3.2%) and have marked social disadvantage when compared to other Australians. The difference in the pattern of critical illness between indigenous and non-indigenous Australians and also whether the performance of the APACHE II scoring system was comparable between these two groups of critically ill patients in Western Australia was assessed (Chapter 4). Both discrimination and calibration are important indicators of the performance of a prognostic scoring system. ... The use of the APACHE II scoring system in patients readmitted to ICU during the same hospitalisation was evaluated and also whether incorporating events prior to the ICU readmission to the APACHE II scoring system would improve its ability to predict hospital mortality of ICU readmission was assessed in chapter 10. Whilst there have been a number of studies investigating predictors of post-ICU in-hospital mortality none have investigated whether unresolved or latent inflammation and sepsis may be an important predictor. Section four examines the role of inflammatory markers measured at ICU discharge on predicting ICU re- 4 admission (Chapter 11) and in-hospital mortality during the same hospitalisation (Chapter 12) and whether some of these inflammatory markers were more important than organ failure score and the APACHE II scoring system in predicting these outcomes. Section five describes the development of a new prognostic scoring system that can estimate median survival time and long term survival probabilities for critically ill patients (Chapter 13). An assessment of the effects of other factors such as socioeconomic status and Aboriginality on the long term survival of critically ill patients in an Australian ICU was assessed (Chapter 14). Section six provides the conclusions. Chapter 15 includes a summary and discussion of the findings of this thesis and outlines possible future directions for further research in this important aspect of intensive care medicine.
|Qualification||Doctor of Philosophy|
|Publication status||Unpublished - 2008|