Diana L. Rosman

AGE RELATED CHANGES IN DRIVERS' CRASH RISK AND CRASH TYPE

Age and gender differences in the rates of crash involvement of Western Australian drivers were examined using the Road Injury Database of the Road Accident Prevention Research Unit at the University of Western Australia. The population examined was all drivers of cars, station wagons and related vehicles involved in property damage, injury and fatal crashes reported to the police in Western Australia from 1 January 1989 to 31 December 1992. It was found that drivers aged < 25 years were involved in ca 35% of crashes, compared with 3% for drivers 70 years and over. Drivers under 25 years had the highest rates on a population and licence basis, but when the distance travelled was taken into account, rates of crash involvement for the 75 or more age group were as high as those of the youngest age group. Females had higher rates of crash involvement than males in all age groups. Drivers over 70 years were involved in relatively more crashes involving fatalities and hospital admissions than younger drivers, although the number of such crashes was small. The youngest groups of drivers had proportionately more single vehicle crashes, drivers 30-59 years had more same direction crashes, and drivers over 60 years, particularly those over 75 years, had more direct and indirect right angle crashes. There were also age related patterns in the movements associated with these crashes. Drivers under 30 years were associated with swerving and swinging wide, drivers 30-59 years were stopped at the time of the crash disproportionately often, and drivers over 60 years were associated with turning movements. The percentage of crashes in daylight ranged from ca 64% for drivers under 20 years to a maximum of over 90% for those 80 years and over. These patterns are consistent with changes in exposure to risk of crash involvement with age, and also with changes in ability, experience and psychological function, which are also related to age.

THE WESTERN AUSTRALIAN ROAD INJURY DATABASE (1987-1996): TEN YEARS OF LINKED POLICE, HOSPITAL AND DEATH RECORDS OF ROAD CRASHES AND INJURIES

Accurate information about injuries and their causes is essential to road safety research, policy development and evaluation. Such information is most powerful when it is available for all road crashes within a jurisdiction. The Western Australian Road Injury Database achieves this through the on-going linkage of crash details from reports to police with the details of injuries to casualties contained in hospital and death records. Over the 10-year period 1987-1996, 386,132 road crashes involving 142,308 casualties were reported to the police in Western Australia. There were also 47,757 hospital discharge records and 2,906 death records related to road crashes during this period. Of the 142,308 police casualties, 17 848 had a matching hospital discharge record and 2,454 had a matching death registration. Linkage within the hospital records revealed that the 47,757 discharge records involved 43,179 individuals, of whom 39,073 were admitted to hospital once, 3,653 were admitted twice, 374 were admitted three times and 78 were admitted more than three times. Of the 43,179 hospitalised casualties, 817 had a matching death record. Linked police, hospital and death records of road crash casualties provide accurate outcome information for casualties in crashes reported to the police. In addition, estimates of under reporting of crashes for different road user groups can be made by comparing hospital records with and without a matching police record. This article demonstrates the power of a linked system to answer complex research questions related to outcome and under-reporting.

Public good through data linkage: measuring research outputs from the Western Australian Data Linkage System

Objective: To measure the ‘public good’ by retrieving, collating, reviewing and assessing outputs from projects using information supplied from the Western Australian Data Linkage System (WADLS) during 1995‐2003.

Comparison of accident and emergency with police road injury data

This paper examines the consistency of police and hospital reporting of outcomes of road traffic crashes using a database of linked police crash reports and accident and emergency department data. The database used consisted of linked records of road traffic crashes in Western Australia for the period of October 1, 1987 to December 31, 1988 from police reported casualty crashes, the discharge records from all hospital admissions in Western Australia, the Registrar-Generals death records, and records for each ambulance trip as a result of a road crash in the metropolitan area of Perth. The results suggest that police records of hospital admissions from the group of accident and emergency attendances underestimated the total by approximately 15%.

Complementing police road-crash records with trauma registry data--an initial evaluation.

This paper examines the consistency of hospital and police reporting of outcomes of road traffic crashes using a database of linked police crash reports and trauma registry records. Criteria for inclusion into the trauma registry include trauma-related causes with subsequent stay of more than 24 h or death due to injuries. During the 1997 calendar year there were 497 cases of road-related injuries within the combined trauma registry of Sir Charles Gairdner and Fremantle Hospitals, of which only 82% had matching police records. Linkage rates were associated with gender, injury severity and the number of vehicles involved. Within the road user category, pedestrians were least likely to link. Of the linked records, police classification of injury severity was correct in 78% of cases. Male casualties were more likely to be correctly classified than females, after adjustment for related variables including injury severity. Correct classification of injury by police was also closely related to severity of injury. Identification and targeting of these groups of casualties is vital in refining the road-crash reporting system. Increased crash reporting and availability of data from these two sources will provide road authorities with more reliable measures of injury outcome.

Prevalence and Familial Association of Atopic Disease and its Relationship to Serum IgE Levels in 1,061 School Children and Their Families

The prevalence of asthma, hay fever, wheezing bronchitis, and eczema was found to be independent of age and sex in 1,598 school children aged 6–17 years who were resident in Busselton, Western Australia. Prevalence studies show that both asthma and hay fever are inherited diseases but that the mode of inheritance differs, since there is evidence in hay fever but not asthma of a cumulative effect resulting from both parents expressing the disease. The serum IgE levels of children with all categories of allergic disease reported in this study were significantly elevated above those of control children of similar age. The mother’s serum IgE concetration was more closely related to that of her son than to that of her daughter. The converse relationship existed for girls. These findings are interpreted on the basis that the X-chromosome of man carries genes which influence IgE synthesis.

The construction of a road injury database

In order to effectively examine possible causes and determinants of road trauma, reliable information on the participants, circumstances, and resultant injuries and deaths must be available. Characteristics of participants (persons and vehicles) and the circumstances of road accidents are routinely collected by police and road authorities, whereas details of the injuries and medical care provided to casualties are collected by hospital and ambulance services. A road injury database, linking data collected by the Health, Police, and Main Roads Departments of the Government of Western Australia with records of the St. John Ambulance Association and the Death Register, has been established. This paper describes the procedures used to link the various sources of data and discusses the design, construction, and quality of the resultant relational database.

Novice drink drivers, recidivism and crash involvement.

A group of drink drivers with no prior arrest for drink driving was selected from drink driving arrest records originating in Western Australia between 1987 and 1995. These drink-driving records were linked to road crash records for the same period. The analysis of these combined records focussed on the sequence of driving events (i.e., arrests, crashes and arrests resulting from crashes) and the present article explores the relationship in time between known drink driving incidents and crash involvement. Using multi-variate survival analysis, it was found that if a drivers first drink driving offence resulted from a road crash, especially if this occurred at a younger age, he/she was significantly more likely to drink, drive and crash again.

Does health assessment improve health outcomes in Indigenous people? An RCT with 13 years of follow-up

Objective: To examine the impact of a multi‐component health assessment on mortality and morbidity in Kimberley Aboriginal residents during a 13‐year follow‐up.

AN EVALUATION OF ROAD CRASH INJURY SEVERITY MEASURES

Reliable and consistent measures of injury severity are necessary for the study of environmental, crash and personal factors involved in road traffic crashes. This study was designed to evaluate measures of injury severity derived from computerized hospital discharge records, using 3609 road crash casualties admitted to hospital in Western Australia in 1988. External cause of injury codes were used to identify injuries from road traffic crashes. The ICDMAP software was used to convert the diagnosis codes into Abbreviated Injury Scale (AIS) scores for each body region. The maximum AIS values were derived using (1) all 12 diagnosis codes; (2) the first six diagnosis codes; and (3) the principal diagnosis code alone. Other measures of injury severity evaluated were the number of body regions with at least one injury; the number of regions with Abbreviated Injury Severity score of three or more; and total number of days spent in hospital. Discriminant analysis suggested that the AIS could be separated into minor and major injuries at a score of three and the Injury Severity Score at a score of nine. The measures derived from the AIS were all strongly correlated with each other and with the length of hospital stay and the dichotomized values gave similar results to the other scores when used in regression analyses of the injury experience of different types of road users. It was concluded that measures incorporating elements of both severity and number of injuries were preferable but length of hospital stay would be a suitable proxy if no other injury information was available.