Pedal cycle injuries in NSW: A comparison of data sources

Road & Transport Research, Dec 2003 by Voukelatos, Alex, Rissel, Chris, Campbell, Fiona

Abstract

In NSW, police data are used as the basis for Roads and Traffic Authority (RTA) accident and injury statistics (after filtering and removal of inconsistencies). These RTA data are the primary data on which decisions regarding motor vehicle and traffic injury prevention policies and programs are based. For a variety of reasons, the RTA injury data are not consistent with comparable motor vehicle accident data from the NSW hospital Inpatient Statistics Collection (ISC). To understand the degree of inconsistency between the RTA and ISC databases and policy implications, we analysed injury data for 1999-2000 for pedal cycle and motor vehicle accidents, applying the same filters. We found that the RTA data consistently over-represented the number of injuries for motor vehicle drivers and passengers, and underestimated the injuries for pedal cycles when compared with hospital data. This finding suggests that the RTA is likely to focus more injury-prevention resources on motor vehicle crashes, and pedal cycle injury prevention is likely to receive fewer resources than is warranted.

INTRODUCTION

The Roads and Traffic Authority (RTA) is the peak agency in New South Wales (NSW) with responsibility for reporting transport-related injuries and deaths. In Australia, routinely collected data on road crashes and injury indicate that a peak in the annual number of road users killed was reached in 1970, with 3798 deaths, after a steady rise since the turn of the century (Bellew et al. 2002). Following a series of road safety campaigns, the national figure has been more than halved since 1970, despite a 51% increase in the national population, and an increase of more than 50% in motor vehicle registrations between 1970 and 2000 (Bellew et al. 2002). Similarly, in NSW RTA statistics report a peak in motor vehicle occupant fatalities of 1080 in 1978, with a decrease of about 50% in recent years (RTA 2001).

The total number of injuries to motor vehicle occupants in NSW has also decreased by about 40%, since a peak in 1978 of 35 000 injuries (RTA 2001). In contrast, the number of road accident-related injuries to pedal cyclists in NSW steadily increased, with a peak in 1988 (1949 injuries) and a slow decrease since then (RTA 2001).

There are several sources of information to describe transport-related morbidity and mortality. The RTA draws on mortality data derived from one of the databases managed by the Registry of Births, Deaths and Marriages and collated by the Australian Institute of Health and Welfare (RTA 2001). For injuries, the RTA uses data collected by police reports of traffic accidents. These data are directly entered by the reporting officer into a computerised database, and forwarded to the RTA on a weekly basis. The data are then entered into an RTA database for enhancement and validation (RTA 2001).

However, the hospital system provides an alternative source of information about transport-related morbidity and mortality. It has been shown that there is considerable variation in the number of accidentrelated injuries when reports made to the road transport authorities are compared with reports made to the hospital system. For example, in Western Australia, according to the Office of Road Safety, the ratio of pedal cycle accident-related injuries to motor vehicle accident-related injuries is approximately 1:25, whereas according to hospital admission data this ratio is 1:2 (Legge, Kirov & Cercarelli 2000). In NSW the equivalent ratio of pedal cycle accident-related injuries to motor vehicle accident-related injuries from the RTA is approximately 1:20 (RTA, 2001). However, when the primary injury database used by health services to report injuries is examined, the conclusion reached in the Chief Health Officer's 2002 report is that the RTA assessment of pedal cycle injuries "appears tobe a considerable underestimate" (NSW Department of Health 2002) when RTA figures for the year 2000 are compared with the data in the Inpatient Statistics Collection (ISC) for the year 1999-2000 (HOIST 2002).

In this study we re-analyse the NSW transport-related injury data from the RTA and the ISC to investigate comparability and to identify any disparities between the databases for pedal cycle injuries.

METHOD

Traffic-related injury data published by the RTA (RTA, 2001) and hospitalisation data collected by the NSW Health Department and accessible from the Inpatients Statistics Collection were re-analysed and compared.

RTA data

Data from the RTA were taken from the report Road Traffic Accidents in NSW 2000, More specifically, casualty data from table 27b,p.65, (RTA2001) were retabulated, separating injuries into injuries to pedal cyclists and motor vehicle occupants. As previously mentioned, all RTA accident data is obtained from police reports. Reporting of road accidents to the RTA conform to the national guidelines for reporting road vehicle accidents, the main criteria of which are (1 ) the accident was reported to the police, (2) the accident occurred on a road open to the public, (3) the accident involved at least one moving road vehicle, and (4) the accident involved at least one person being killed or injured or at least one motor vehicle being towed away (RTA 2001). Despite these guidelines, it is acknowledged that current methods of reporting road accidents are ineffective in capturing non-fatal pedal cyclist accidents. Nevertheless, RTA data of road vehicle accidents involving pedal cycles versus motor vehicles for the year ending 31 December 2000 are shown in Table 1.