ABSTRACT Key words: major trauma, mortality, emergency pre-hospital, performance indicators. Australian and New Zealand Standard Research Classifications: Division 11 (Medical and Health Sciences); Group 1117 (Public Health and Health Services) Background Response times are a common performance measure for many ambulance services and emergency medical response systems and are considered to be a standard measure of emergency medical services quality. The development of formalised Emergency Medical Systems in Australia and internationally have almost universally assumed a link between shorter response times and improved patient outcome measured by survival. While the evidence to support time-criticality for patients who experience a cardiac arrest is considered unequivocal, the assumption that response and scene times are universally important across all patient groups is not consistently supported by the research evidence. Little is known about whether or not the importance of time-dependent performance measures vary as a function of the Emergency Medical System arrangements to which they apply, the skill set of attending paramedics or the epidemiology of the target population. Despite this, response times continue to be one of the key performance measures for ambulance services regardless of the wider health services system in which they operate. Given the significant investment in paramedic training and increasing levels of clinical responsibility witnessed in the last decade, the development of a robust body of evidence about whether this investment and expertise alters outcomes for patients is yet to develop and there has been little shift in measures of performance. Major traumatic injury is associated with significant disease burden in Australia as elsewhere in the world. An estimated 1,500 Queenslanders die each year as a result of major traumatic injury and injury remains the single most common cause of death in Queenslanders between the ages of 1 and 35 years. As such, injury has a massive impact on the health of Queenslanders. Each year, around 10% of Queenslanders will suffer from an injury of some kind and it is known that injury results in 10% of all hospital admissions and 40-60% of attendances at hospital Emergency Departments. In Australia, injury is recognised as one of the seven National Health Priority Areas by the Australian Government. While this document provides for the setting of broad targets for reduction in injury and its social, economic and health corollaries, little advice is provided regarding health service performance with this target group. The emergency pre-hospital environment is absent in this and most strategic policy documents of this ilk in Australia. This thesis has two core aims: • to provide for the first time a descriptive analysis of major trauma in Queensland for the period 1998-2001 including description of the systemic factors influencing patient mortality; and in the light of these findings to • examine the utility of emergency pre-hospital time-dependent performance indicators as predictors of mortality in this patient group. The period of interest 1998-2001 was selected to provide a baseline for the development of the Queensland Trauma Plan implemented by government in 2007. Methods This thesis involved three key activities: (1) a review of the literature on the basis for time-dependent measures of pre-hospital performance in trauma, impacts of system design and emergency pre-hospital skill set on mortality from major trauma; (2) a descriptive quantitative analysis of linked patient data over a four year period (1998-2001) of the relationship between pre-hospital time and mortality; and (3) the theoretical development of alternative emergency pre-hospital performance measures for trauma. Results Of the 23,462 patients in the study population, 29.0% (n= 6,793) died as a consequence of their injuries. Fifteen percent (15.0%) of the patients died in the pre-hospital environment. After adjustment for age, sex and severity (GCS<9) and the presence or absence of co-morbidities, a response interval in excess of 10 minutes (the State benchmark for high acuity cases) did not affect all-cause, all-age mortality from major trauma (OR 1.03; 95%CI 0.93-1.13) compared to response times < 10 minutes. Similarly, no significant effect of response interval >10 minutes (OR 1.11; 95%CI 0.98-1.26) was noted in the pre-hospital period. Scene time >20 minutes (OR 0.75; CI 0.65-0.86) improved the chance of survival to hospital by comparison to scene times <20 minutes. At all times in the pre-hospital care continuum, the presence of an Intensive Care Paramedic improved survival (OR 1.29; 95%CI 1.13-1.48) when compared to solely Advanced Care Paramedic crews, however this effect was not sustained for overall mortality. Conclusions Traditional time-dependent emergency pre-hospital performance measures are not associated with pre-hospital survival from major traumatic injury in Queensland. This finding differs from the experience of similar systems in Canada and elsewhere and may be due to differences in trauma profile, system arrangements, skill sets and funding models. Alternatively, the system operating in Queensland may in fact be optimised in terms of response, scene and transfer times given the size and geography of the State. This study has confirmed the positive survival benefit associated with highly skilled paramedics in the field and demonstrates that time-dependent performance measures should not be considered proxy measures of survival. New performance indicators specifically targeted to patient outcomes need to be developed to monitor the performance of trauma systems in the pre-hospital sector.

No / Aim To review the recent evidence that has resulted from experiences in and out of conflict in relation to improving imaging in cases of major trauma. Method A search of electronic databases, the internet and Cochrane library was undertaken to identify relevant publications which were analysed in terms of quality. Evidence that has emerged from civilian and military practice that could influence the practice of major trauma imaging in future was discussed. Results The importance of speed in assessing patients suffering major trauma is becoming more recognised. There is growing evidence that the use of portable ultrasound at the site of major trauma as first line investigation has potential. In more stable patients, the evidence for whole body CT at the expense of radiography is also growing. The concern regarding availability and radiation dose related to CT scanning remain significant but with the outcome of the recent Major Trauma Review and improvements in CT scanning techniques, such concerns are being addressed. There is limited research in the use of MRI in relation to major trauma. Conclusion Ultrasound at the sight of major trauma has potential but further research will be needed. Factors such as operator training in particular need to be considered. CT scanning remains an important diagnostic tool for patients suffering major trauma and this is borne out by the Major Trauma Review and NICE guidelines. The availability of CT scanning in relation to accident and emergency scanning is a factor the Major Trauma Review has highlighted and the close proximity of new CT scanners to accident and emergency is a factor that will need to be taken into account in strategic planning. Given the growing evidence of CT involvement, the continued practice of cervical spine and pelvic radiography in cases of major trauma should be questioned.