Low speed vehicle run over (LSVRO) incidents have been identified as a significant cause of transport pedestrian fatalities in young children. Most – if not all - of these deaths are preventable. While literature exists describing the various contributing factors towards fatal and non-fatal LSVROs there is little current research that describes this mechanism of injury in detail, at a population level. Methodological limitations of previous publications have resulted in a lack of adequate information about the true burden surrounding LSVROs. I postulate that this information is crucial in informing effective prevention strategies to reduce the burden of LSVRO incidents. The primary aim of this thesis was to investigate the epidemiology of LSVRO incidents, and identify possible prevention strategies.
Four thesis aims were:
1. To review current literature on LSVRO incidents to assess understanding of morbidity and mortality and risk factors from LSVROs.
2. To estimate the incidence of fatal and non-fatal LSVROs in Queensland involving children aged 0-15yrs for the 11 year period, January 1999 to December 2009.
3. To identify the characteristics of children involved in LSVROs and to define the associated patterns of injury.
4. To determine whether the incidence of LSVROs, characteristics of children sustaining these events, or injury characteristics differed with respect to geographical remoteness or Aboriginal or Torres Strait Islander status.
This thesis involved three sub - studies:
1. Systematic Literature Review:
Current knowledge of the incidence of LSVRO events was investigated through a systematic review of the literature. The recommendations of the United Kingdom (UK) Centre for Reviews and Dissemination were implemented regarding search methods. From my search results the Power Frank “Quality Assessment Checklist” was used for quality appraisal, data extraction and analysis to complete this review .
2. Retrospective Cohort:
A total population-based retrospective cohort study was completed to ascertain the best estimate possible for fatal and non-fatal LSVRO events among children aged 0-15 years in Queensland between 1999-2009. Data were obtained independently from five separate data bases. This array of data sets represents the continuum of care available in Queensland, capturing the sequence of events (including pre-hospital care; emergency care; injury surveillance, hospital admission; death), which were manually linked. Crude Incident Rates (IR) were calculated using population data for: each year of age per calendar year of the study, fatal and nonfatal events; all LSVRO events; males and females; and for the total population, Indigenous Australian and non-Indigenous Australian children; and for geographical remoteness. Descriptive analyses were used to analyse the sample characteristics in relation to demographics, health service usage, incident characteristics; and injury characteristics.
Between 1999-2009 there were 1,611 LSVRO incidents among 0-15 year old Queensland residents (IR 16.87 per annum; male=IR 20.97, female = IR 12.55). Non-fatal events were 61.5 times more frequent than fatal LSVRO events during this period. Incidence rates were highest among children aged 0-4yrs – 21.45 per 100,000 per annum. Differences in incidence, injury characteristics (severity and type), and event characteristics, were observed in relation to age, gender, socio-economic status, Indigenous status, and geographical remoteness.
Over half the children involved in an LSVRO required admission to hospital (56%, n=921); mean length of stay was 3.4 days. Consequences of LSVRO events were worse for children who lived outside major cities (an inverse association between remoteness and severity), and children who were identified as Indigenous (longer stays in hospital). Parents were most commonly the vehicle drivers in fatal incidents. While larger vehicles such as four-wheel drives (4WD) were most frequently involved in LSVRO events resulting in fatalities, cars were most frequently involved in non-fatal events.
This is the most comprehensive population-based epidemiological study on fatal and non-fatal LSVRO events to date. This study highlights that children most at risk of being involved in a LSVRO event are aged 0-4 years, male, reside in outer regional or rural and remote areas or are Indigenous Australian children.