J. C. Alsop

Under-reporting of motor vehicle traffic crash victims in New Zealand

Our aim was to ascertain the extent of under-reporting of seriously injured motor vehicle traffic crash victims, as recorded by police in New Zealand, and to what extent this coverage was biased by crash, injury, demographic, and geographic factors. Hospital data and police records were linked using probabilistic methods. During 1995, less than two-thirds of all hospitalised vehicle occupant traffic crash victims were recorded by the police. Reporting rates varied significantly by age, injury severity, length of stay in hospital, month of crash, number of vehicles involved, whether or not a collision occurred, and geographic region, but not by gender, ethnicity or day of the week of the crash. Those using these police files for prioritization, resource allocation and evaluation purposes need to be aware of the extent and nature of these biases contained within these databases.

The New Zealand rugby injury and performance project. VI. A prospective cohort study of risk factors for injury in rugby union football

Objectives—Although the nature of rugby injury has been well documented, little is known about key risk factors. A prospective cohort study was undertaken to examine the association between potential risk factors and injury risk, measured both as an injury incidence rate and as a proportion of the playing season missed. The latter measure incorporates a measure of injury severity. Methods—A cohort of 258 male players (mean (SD) age 20.6 (3.7) years) were followed through a full competitive season. At a preseason assessment, basic characteristics, health and lifestyle patterns, playing experience, injury experience, training patterns, and anthropometric characteristics were recorded, and then a battery of fitness tests were carried out. Results—A multiple regression model identified grade and previous injury experience as risk factors for in season injury, measured as an injury incidence rate. A second model identified previous injury experience, hours of strenuous physical activity a week, playing position, cigarette smoking status, body mass index, years of rugby participation, stress, aerobic and anaerobic performance, and number of push ups as risk factors for in season injury, measured as proportion of season missed. Conclusions—The findings emphasise the importance of previous injury as a predictor of injury incidence and of missing play. They also show the importance of considering both the incidence rate and severity of injury when identifying risk factors for injury in sport.

HEAD INJURIES TO BICYCLISTS AND THE NEW ZEALAND BICYCLE HELMET LAW

The purpose of this study was to examine the effect of helmet wearing and the New Zealand helmet wearing law on serious head injury for cyclists involved in on-road motor vehicle and non-motor vehicle crashes. The study population consisted of three age groups of cyclists (primary school children (ages 5-12 years), secondary school children (ages 13-18 years), and adults (19+ years)) admitted to public hospitals between 1988 and 1996. Data were disaggregated by diagnosis and analysed using negative binomial regression models. Results indicated that there was a positive effect of helmet wearing upon head injury and this effect was relatively consistent across age groups and head injury (diagnosis) types. We conclude that the helmet law has been an effective road safety intervention that has lead to a 19% (90% CI: 14, 23%) reduction in head injury to cyclists over its first 3 years.

Impact of graduated driver licensing restrictions on crashes involving young drivers in New Zealand

Objective—To determine the impact on young driver crashes of the three main driving restrictions in the New Zealand graduated driver licensing (GDL) system: night-time curfew, no carrying of young passengers, and a blood alcohol limit of 30 mg/100 ml. Method—The database for this study was created by linking police crash reports to hospital inpatient records (1980–95). Multivariate logistic regression was used to compare car crashes involving a young driver licensed before GDL (n=2252) with those who held a restricted graduated licence (n=980) and with those who held a full graduated licence (n=1273), for each of the main driving restrictions. Results—Compared with the pre-GDL group, the restricted licence drivers had fewer crashes at night (p=0.003), fewer involving passengers of all ages (p=0.018), and fewer where alcohol was suspected (p=0.034), but not fewer involving young casualties (p=0.980). Compared with the pre-GDL drivers, those with the full graduated licence had fewer night crashes (p=0.042) but did not differ significantly for any of the other factors examined. Conclusion—These results suggest that some of the GDL restrictions, especially the night-time curfew, have contributed to a reduction in serious crashes involving young drivers.

An evaluation of the general effect of the New Zealand graduated driver licensing system on motorcycle traffic crash hospitalisations

In 1987, New Zealand introduced a comprehensive Graduated Driver Licensing System (GDLS) which was designed to allow new drivers to gain driving experience while being excluded from high risk situations. This study sought to evaluate the impact of the GDLS on motorcycle traffic crashes that resulted in serious injury. Injury crash data were obtained from the New Zealand Health Information Services national public hospital inpatient data files for the years 1978-1994, inclusive. Cases were disaggregated into three age groups, 15-19 years, 20-24 years, and 25 years or older, for which injury trends were obtained. In order to determine whether trends in motorcycle traffic crashes simply followed national trends in other injury events, two non-traffic comparison groups for the main target group (15-19 years) were included. Using time series analyses, the introduction of the GDLS was found to be closely followed by a significant reduction (22%) in motorcycle traffic crash hospitalizations for the 15-19 year age group. An examination of vehicle registration and driver licensure data suggests that the reduction in injury crashes may, largely, be attributable to an overall reduction in exposure to motorcycle riding.

Temporal patterns of injury during a rugby season.

The aim of this study was to describe temporal patterns in the frequency, nature and circumstances of injuries occurring among a cohort of 356 rugby players during a club rugby season in New Zealand. It was found that the rate of injury in games decreased significantly over time in both males and females. The reduction in injury rate over the season was more pronounced in some grades, but no differences were found when examined by gender. playing position, age, ethnicity or by health and fitness types. Trends in injury rate were consistent over the rugby season and did not appear to be the result of a bias involving under-reporting of end-of-season injuries. The types and severity of injury remained relatively constant, but the proportion of injuries occurring in back play fell significantly over the season and injuries were more likely to occur in the trunk body region as the season progressed. This study supported the hypothesis that higher rates of injury occur at the start of the rugby season and decrease over the course of the season. This reduction is consistent over time and across player types, and is not attributable either to decreasing injury severity or to increasing player fitness.

Achieving compliance with pool fencing legislation in New Zealand: a survey of regulatory authorities

Objectives—To identify the status of compliance and enforcement of New Zealands Fencing of Swimming Pools Act (FOSP Act), 10 years after its introduction, and to identify methods for improving both compliance with the act and the process of enforcement. Methods—A postal questionnaire was sent to all 74 authorities in New Zealand in which they were asked questions about their enforcement of the FOSP Act. Semistructured telephone interviews were conducted with 12 authorities to supplement the data obtained in the postal survey. Results—Based on responses to the survey, it was estimated that there are over 59 000 domestic swimming pools in New Zealand, giving rates of 46 pools/1000 dwellings and 16 pools/1000 persons. The authorities reported that 44% of pools complied with the act, and a further 4% had been granted exemptions. Nineteen per cent of pools were reported to not comply with the act, and the compliance status of a further 33% was not known, or not stated by the authority. Only 9% of authorities had procedures for locating and inspecting pools, while 28% had a programme of reinspection to ensure that pools continued to comply. Pool owner resistance was considered to be the main difficulty with enforcing the act, and nearly half of the authorities believed publicity or education was needed to overcome these barriers. Fifty two per cent of authorities had publicised the act during the 12 months preceding the survey. Conclusions—Due to ambiguities within the legislation, and differing levels of commitment by authorities to locate pools and monitor compliance, compliance with the FOSP Act is not consistent nationally. If the act were less ambiguous, there would be greater consistency and more enforcement.

A LONGITUDINAL INVESTIGATION OF PSYCHOLOGICAL AND SOCIAL PREDICTORS OF TRAFFIC CONVICTIONS AMONG YOUNG NEW ZEALAND DRIVERS

The study aimed to determine whether young drivers with traffic conviction records differed from those without, with respect to prior personal characteristics measured around the minimum age of licensure (presently 15 years in New Zealand). From a broad range of psychological and social factors, the strongest and most stable predictors were male gender, part time work, rural residence, marijuana use, estimated driving exposure during the follow up period, and early motorcycle riding. Experiences of riding as a passenger with young drivers or with an alcohol intoxicated adult driver were also significant predictors. Some possible countermeasures are considered. (a) For the covering entry of this conference, please see IRRD abstract no. E200232.

Playing conditions, player preparation and rugby injury: a case-control study

This paper investigates the effect of player preparation, ground conditions and weather conditions upon the injury risk for Rugby Union players. A population-based case-control study was performed using a sample (n= 1043) of New Zealand Rugby Union players aged 16 y and above. Details concerning game preparation (warm-up and usual position), and ground and weather conditions (precipitation, wind and temperature) were obtained from the players. If players were injured during the season (n= 624) they were asked to provide details about the game in which they were last injured. Uninjured players (n= 419) provided details about the last game in which they played. Injuries were more likely to occur when games were played on hard grounds or in calm or warm conditions. Playing out of position and the duration of warming up did not significantly alter the risk of injury. When player preparation, ground and weather conditions, grade, age, playing position and rugby experience were simultaneously controlled for, hard ground and the absence of wind were associated with increased risk. The influence of these factors may be indirect, through adaptation to the conditions in which a game is played.

Tractor Fatalities and Injury on New Zealand Farms

The aim of the research was to describe the epidemiology of tractor incidents on New Zealand farms which resulted in death or hospital inpatient treatment. Fatalities were identified from three independent data files for the period 1986-1991. Hospitalizations were selected from national hospital inpatient files for the period 1980-1989. There were 51 deaths, an average of 8.5 per year, or an estimated rate of 1 per 100,000 rural residents per year. Only 47% of the cases were recorded on all three databases. Those in the 60+ age group had the highest number and rates of fatal injury. There were 1,151 incidents requiring inpatient treatment, an average of 115 per year, or an estimated rate of 22 per 100,000 rural residents per year. Males in the 15 to 19 age group had the highest gender specific rate. At least 23% of the fatalities and 45% of the non-fatal injuries occurred to persons whose primary occupation was other than farming. When specific events were examined as a proportion of all events, there had been a significant decline in non fatal overturns. Our analyses also show that this was not due to other types of crash increasing over time. While overturns were an important cause of fatalities and non-fatal injury, the non-fatal injury analyses highlights the fact that the majority of tractor incidents did not appear to involve overturns. Efforts to reduce mortality and morbidity associated with tractors would be greatly facilitated by: an enhancement of national surveillance systems; in-depth studies into specific classes of events with priority being given to ?overturns?; and consideration of the elderly, children, and those whose primary occupation is not related to farming. In addition, existing and proposed legislation needs to be reviewed to ensure that it comprehensively addresses protection for all tractor users and roll over protection.