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.

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.

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.

Dying to go on holiday.

OBJECTIVE: The Christmas period road toll is a highly publicized 'summary' of the number of road deaths that occur each year during New Zealand's summer holiday period. Our aims were to identify significant changes in the Christmas road toll during 1968-98, highlight the ability to detect changes and determine if focusing on the changes in the Christmas road toll provided a useful insight into trends in fatal crashes. METHODS: Regression modelling of the number of fatalities was used to examine trends in the Christmas road toll in New Zealand over time. A power analysis was used to investigate the ability to detect significant reductions in the Christmas road toll. RESULTS: The Christmas road toll has not decreased significantly in the past 30 years and has not improved significantly in contrast to the rest of the year. The number of deaths in any given year can be expected to vary 'naturally' between 10 and 39. The statistical power to detect a hypothetical 19% reduction in the Christmas road toll is minimal. CONCLUSIONS: Stochastic fluctuations in the Christmas road toll make it extremely difficult to identify underlying trends, even if substantial. Little insight can be gained from yearly comparisons of road tolls considered over short periods. More focus should be placed on road tolls that are calculated over longer periods, e.g. the previous six months. IMPLICATIONS: Natural fluctuations arising in small counts will make it difficult to highlight real improvements in road tolls.

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.

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 Zealand's 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 publicized 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.

The New Zealand Rugby Injury and Performance Project: V. Epidemiology of a season of rugby injury.

OBJECTIVE: To describe the incidence, nature, and circumstances of injury experienced by a cohort of rugby union players during a full competitive club season. METHODS: A prospective cohort study followed up 356 male and female rugby players throughout the 1993 competitive club season. Players were interviewed by telephone each week to obtain information on the amount of rugby played and the injury experienced. RESULTS: Detailed information was collected for 4403 player-games and 8653 player-practices. A total of 671 injury events were reported, of which 569 were rugby related. The injury rate for games was higher than that for practices (rate ratio 8.3). At 10.9 injuries per 100 player-games, males had a higher rate of injury than females at 6.1 injuries per 100 player-games (p<0.001). Injury rates varied by position, with male locks (13.0 injuries per 100 player-games) and female inside backs (12.3 injuries per 100 player-games) having the highest rate in their respective sexes. The lower limb was the body region most often injured in games (42.5%) and practices (58.4%). Sprains/strains were the most common type of injury in games (46.7%) and practices (76.1%). In games the tackle was the phase of play in which the most injuries occurred (40%), followed by rucks (17%) and mauls (12%). Thirteen per cent of game injury events were the result of foul play. CONCLUSIONS: Rugby injury was common among the study subjects and varied according to grade and gender. Identifying the causes of injuries in the tackle, lower limb injuries, and dealing with the issue of foul play are priority areas for the prevention of rugby injury.

Trends in motorcyclist and occupant fatalities and serious injuries due to traffic crashes.

AIM: To describe trends in motorcycle traffic crashes and compare these trends in other crashes and vehicle registrations. METHOD: National fatality and public hospital inpatient data were used to select cases. Relative changes in both deaths and hospitalisations, and vehicle registrations were examined in each year during the period 1980-98. RESULTS: The results show that deaths and serious injuries to motorcyclists have declined substantially over the period 1980-1995. The trend in serious injuries to motorcyclists closely followed the trend in motorcycle registrations. The association was less evident for motorcyclist fatalities and for occupants there was no clear association with trends in registrations for either outcome. CONCLUSIONS: The reduction in motorcycle injuries has contributed substantially to our improved road safety record. We need to protect these gains but in order to do this we need a clear understanding of how they were achieved. Such an understanding is currently lacking.

Determining first admissions in a hospital discharge file via record linkage.

The aim of this study was to identify first admissions in a public hospital discharge file with the greatest possible accuracy. Computerised data linkage was used to link injury events. This involved the use of "internal" data linkage (unduplication) which, in data linkage terms, is equivalent to matching two identical files. Admission status indicators obtained from deterministic and probabilistic linkages were compared with those obtained from a manual review. Small absolute reductions in error were obtained using a probabilistic linkage over a deterministic linkage. However, these reflected large relative reductions in error. A validity check confirmed initial results and discounted against possible bias due to the subjective nature of the probabilistic linking procedure.

Airgun injuries in New Zealand, 1979-92.

OBJECTIVES: To describe the epidemiology of serious airgun injury in New Zealand. METHODS: Cases were selected from the New Zealand Health Information Service's hospital inpatient morbidity data files for the period 1979 to 1992 inclusive. RESULTS: There were 718 airgun related injuries resulting in 1.56 injuries/100,000 population/year. Males and 10-14 year olds had higher than average rates of injury. The majority of the incidents were unintentional. There has been a marked decline in injury rates since 1989. CONCLUSIONS: Airgun injuries, while not as serious as powder firearm injuries, account for a significant personal and societal burden. The results suggest that strategies aimed at controlling these injuries, especially those pertaining to children, are in need of review.