A cohort study of 20,822 young drivers: the DRIVE study methods and population.

BACKGROUND AND OBJECTIVE: Research on young drivers directly linking risk factors to serious injury and death outcomes is required. The DRIVE Study was established to facilitate this aim. This paper outlines the study methods and describes the population that has been recruited, in order to demonstrate that the necessary heterogeneity in risk factors has been attained. DESIGN, SETTING AND PARTICIPANTS: Drivers aged 17-24 years holding their first-stage provisional driver's licence from New South Wales, Australia, were recruited into a prospective cohort study. The participants were contacted by mail and asked to complete the study questionnaire at an online site or via a mailed questionnaire. Baseline data collection involved a questionnaire with questions to drivers about their training, risk perception, driver behavior, sensation-seeking behavior and mental health. Participants gave consent for prospective data linkage to their data on licensing, crashes and injuries, held in routinely collected databases. RESULTS: 20 822 drivers completed the baseline questionnaire, of whom 45.4% were men, 74.3% resided in capital cities and 25.7% in regional or remote areas. The recruited study population showed a wide variation in the risk factors under examination. For example, almost 40% of drivers reported drinking alcohol at hazardous levels and about 32% of participants seemed to be at a high or very high risk of psychological distress. Participants reported a mean of 67.3 h (median 60 h) of supervised driver training while holding their learner's permit. CONCLUSIONS: The DRIVE Study has a robust study design aimed at minimizing bias in the collection of outcome data. Analyses of baseline data showed substantial heterogeneity of risk factors in the study population. Subsequent prospective linkages comparing relative differences in exposures at baseline with the outcomes of interest have the potential to provide important new information needed to develop targeted interventions aimed at young drivers.

The New Zealand Blood Donors' Health Study: baseline findings of a large prospective cohort study of injury.

INTRODUCTION: Cohort studies have contributed important scientific knowledge regarding the determinants of chronic diseases. Despite the need for etiologic investigations, this design has been infrequently used in injury prevention research. OBJECTIVES: To describe the baseline findings of the New Zealand Blood Donors' Health Study, a large prospective study designed to investigate relationships between lifestyle, psychosocial factors, and serious injury due to road crashes, falls, self harm, assault, work, sport, and recreation. METHODS: Participants were recruited from fixed and mobile collection sites of a voluntary non-profit blood donor program. Baseline exposure data (for example risk taking behaviors, alcohol and marijuana use, sleep habits, and depression) were collected using a self administered questionnaire. Outcome data regarding serious injury will be collected prospectively through computerized record linkage of participants' unique identifiers to national morbidity and mortality databases. RESULTS: In total, 22 389 participants enrolled in the study (81% response rate). The diverse study population included 36% aged 16-24 years, 20% rural residents, and large variability in exposures of interest. For example, in the 12 months before recruitment, 21% had driven a motor vehicle when they considered themselves over the legal limit for alcohol, and 11% had been convicted of traffic violations (excluding parking infringements). Twelve per cent had seriously considered attempting suicide sometime in their life. CONCLUSIONS: This is the first, large scale cohort study investigating determinants of serious injury in New Zealand and among the largest worldwide. Preliminary findings from prospective analyses that can inform injury prevention policy are expected within five years.

A decade of intensive care unit trauma admissions in Auckland.

AIMS: To describe the demographics, nature and severity of injury of trauma admissions to a New Zealand urban Intensive Care Unit (ICU) over a ten year period; to determine differences in injury characteristics between patients received from inside and outside the local trauma catchment area; and to calculate incidence rates in the local population served, to identify high risk groups of patients. METHODS: We carried out a cross-sectional analysis of a prospective ICU patient registry. Data on all trauma admissions from 1988 to 1997 to the ICU of a large New Zealand urban hospital were studied with respect to age, gender, ethnicity, injury type and severity, and referral status. National Census data for the ICU catchment area were used to calculate incidence rates for local admissions. RESULTS: A total of 2305 trauma patients were admitted over the period of the study, accounting for 25% of all ICU admissions. The median age was 28 years and 75% were males. Blunt trauma, mostly due to motor vehicle crashes, accounted for 95% of admissions and penetrating trauma was very rare. The median Injury Severity Score (ISS) was 26 and most life threatening injuries occurred in the head region. Referred admissions were more severely injured and had a higher prevalence of severe head injury than local admissions. The ICU trauma admission rate for local patients was 34.6 per 100,000 person-years. Males had a higher rate than females in all age groups. New Zealand Europeans made up the majority of admissions, but Maori and Pacific Island males had the highest incidence rates. CONCLUSIONS: This study identified trauma as a major component of the ICU population. ICU trauma admissions were characterised by young males with head injuries resulting from motor vehicle crashes. Referred admissions were more severely injured than local admissions and would thus distort the estimated incidence of trauma in the local geographic region served. Calculation of incidence rates highlighted a significantly higher risk of ICU trauma admission amongst Maori and Pacific Islands people than New Zealand Europeans.

Falls prevention over 2 years: a randomized controlled trial in women 80 years and older.

BACKGROUND: after 1 year, a home-based programme of strength and balance retraining exercises was effective in reducing falls and injuries in women aged 80 years and older. The exercise programme had been individually prescribed by a physiotherapist during the first 2 months of a randomized controlled trial. OBJECTIVE: we aimed to assess the effectiveness of the programme over 2 years. SUBJECTS: women from both the control group and the exercise group completing a 1-year trial (213 out of the original 233) were invited to continue for a further year. METHODS: falls and compliance to the exercise programme were monitored for 2 years. RESULTS: 81 (74%) in the control group and 71 (69%) in the exercise group agreed to continue in the study. After 2 years, the rate of falls remained significantly lower in the exercise group than in the control group. The relative hazard for all falls for the exercise group was 0.69 (95% confidence interval 0.49-0.97). The relative hazard for a fall resulting in a moderate or severe injury was 0.63 (95% confidence interval 0.42-0.95). Those complying with the exercise programme at 2 years had a higher level of physical activity at baseline, were more likely to have reported falling in the year before the study and had remained more confident in the first year about not falling compared with the rest of the exercise group. CONCLUSIONS: falls and injuries can be reduced by an individually tailored exercise programme in the home. For those who keep exercising, the benefit continues over a 2-year period.

One year follow-up of an emergency department protocol for abused women.

OBJECTIVE: To evaluate if the positive effects of an initially successful emergency department protocol of care for victims of partner abuse (PA) were maintained at one year follow-up. METHOD: A community intervention trial compared two public hospital EDs in Auckland, NZ, at baseline (BL), following implementation of a PA intervention (PI), and at one year follow-up (FU). The initial intervention involved training staff at one ED in a protocol for the identification and acute management of abused women. Later, an on-site protocol co-ordinator worked to ensure that new staff received training in protocol use. Outcomes were assessed by reviewing a random sample of women's medical records. Identification of PA was assessed for each record on a yes/no basis. Identified cases were classified as 'confirmed' or 'suspected' PA. Acute management was assessed by ascertaining staff use of interventions and documentation of abuse. RESULTS: Approximately equal numbers of records were reviewed at each ED at BL, PI and FU (total n = 10,961). Significant interactions were found for classification of PA and acute management offered to victims between EDs over the different study phases. However, the increase in identification of confirmed cases and the improved acute management offered to identified victims found at the intervention ED in the PI phase were not maintained at follow-up. CONCLUSION: Although staff training in the use of protocols for victims of partner abuse can result in improved care, these effects were not maintained. IMPLICATIONS: More intensive institutional efforts are needed if protocol benefits are to be maintained.

Trauma-related hospitalizations among urban adolescents in New Zealand: priorities for prevention.

PURPOSE: To: (a) determine the magnitude, characteristics, and in-patient costs of injury among hospitalized urban adolescents in New Zealand (NZ); (b) identify regional priorities for injury prevention and investigative research; and (c) compare the study findings with published data from other industrialized countries. METHODS: The 1989-1993 files of the NZ Hospital Discharge Database were accessed to identify and analyze trauma-related admissions of adolescents residing in NZ's largest metropolitan region. RESULTS: The estimated 9569 hospitalizations for injury accounted for one-fourth of all adolescent admissions in the region, a mean annual hospitalization rate of 1292/100,000 population and a minimum annual cost of NZ $5.8 million for in-patient care. Males and indigenous Maori youth had comparatively higher rates of hospitalizations for most major causes of injury. Falls, pedal cyclist injury, cuts, and piercing injuries were leading causes of hospitalization for trauma in early adolescence. Admission rates for motorcylist and other motor vehicle occupant trauma and self-inflicted injury increased substantially among older adolescents. Sport and recreational activities comprised at least one-sixth of injury admissions. CONCLUSIONS: The overall rates of injury resulting in hospitalization among Auckland adolescents were comparable to those reported from Australia and France, but higher than those from the United States, Canada, and Israel. By identifying priority issues and high-risk groups, this study provides a foundation for regional injury control initiatives. It also demonstrates the utility and limitations of E-coded hospital discharge registries in defining the burden of serious nonfatal trauma.

Psychotropic medication withdrawal and a home-based exercise program to prevent falls: a randomized, controlled trial.

OBJECTIVE: To assess the effectiveness of psychotropic medication withdrawal and a home-based exercise program in reducing falls in older people. DESIGN: A randomized controlled trial with a two by two factorial design. SETTING: Seventeen general practices in Dunedin, New Zealand. PARTICIPANTS: Women and men aged 65 years registered with a general practitioner and currently taking psychotropic medication (n = 93). INTERVENTIONS: Two interventions: (1) gradual withdrawal of psychotropic medication versus continuing to take psychotropic medication (double blind) and (2) a home-based exercise program versus no exercise program (single blind). MEASUREMENTS: Number of falls and falls risk during 44 weeks of follow-up. Analysis was on an intent to treat basis. RESULTS: After 44 weeks, the relative hazard for falls in the medication withdrawal group compared with the group taking their original medication was .34 (95% CI, .16-.74). The risk of falling for the exercise program group compared with those not receiving the exercise program was not significantly reduced. CONCLUSIONS: Withdrawal of psychotropic medication significantly reduced the risk of falling, but permanent withdrawal is very difficult to achieve.

A prospective cohort study of blood donors: methodological issues in the investigation of injuries and chronic diseases.

Blood donors have made important contributions to research, most notably in cross-sectional seroprevalence studies. The proposed New Zealand Blood Donors Health Study is a prospective cohort study of 30,000 New Zealand donors designed to investigate the determinants of common injuries, cardiovascular disease and cancer. While robust from an analytic perspective, the execution of prospective cohort studies in many settings is impeded by methodological, economic and organisational barriers. We examined the operational considerations of implementing a large-scale cohort study at a transfusion centre and evaluated measures taken to optimise data collection procedures. A pilot study of 1,000 participants revealed donor motivation to participate in this research was high (91% response rate). Comprehensive exposure data on lifestyle, behavioural and psychosocial factors were obtained from 95% of participants. Substantial heterogeneity in levels of potential risk factors was noted among respondents. Detailed dietary habit information and a study blood sample were obtained from 67% and 100% of participants, respectively. Study recruitment and baseline data collection was feasible during routine donor visits with minimal interruption to donor centre staff and procedures. We conclude the study design and characteristics of the regional donor program enhance the efficiency and significance of the proposed research.

Outcome evaluation of an emergency department protocol of care on partner abuse.

STUDY OBJECTIVE: To evaluate the impact of a protocol on partner abuse (PA) at increasing identification and improving acute management of abused women by emergency department (ED) staff. METHODS: A community intervention trial compared two public hospital EDs at baseline and following implementation of a PA intervention. The intervention involved training staff at one ED in a protocol for the identification and acute management of abused women. Outcomes were assessed by reviewing a random sample of women's medical records. Identification of PA was assessed for each record on a yes/no basis. Identified cases were classified as 'confirmed' or 'suspected' PA. Acute management was assessed by ascertaining staff documentation of abuse and use of interventions. RESULTS: Approximately equal numbers of records were reviewed at each ED, pre and post implementation (total n = 8,051). Eighty-nine per cent of ED staff were trained. No difference in the overall identification of PA was found (chi 2 = 0.13, p = 0.72), but logistic regression analyses showed other significant changes. At the intervention site, there was an increase in confirmed cases of PA (chi 2 = 7.6, p = 0.006), a trend towards increased documentation (chi 2 = 3.5, p = 0.06) and a significant increase in interventions offered (chi 2 = 13.8, p = 0.002). Changes at the comparison site failed to reach significance. CONCLUSION: Implementation of this protocol resulted in a moderate increase in confirmed cases of abuse and improved the acute management offered to identified victims. The findings reinforce recommendations for widespread implementation of training and protocols to address partner abuse.

Indicators of assault-related injuries among women presenting to the emergency department.

STUDY OBJECTIVE: We sought to determine whether women presenting for treatment of assault-related injuries at a public hospital emergency department differed from those presenting for unintentional injuries with regard to a variety of demographic and presentation characteristics, nature and anatomic site of injury, and admission or follow-up treatment for injury. METHODS: We conducted a random-sample retrospective medical record review of women aged 15 years and older who presented at either of 2 24-hour public-hospital emergency departments in Auckland, New Zealand. The characteristics of women identified as presenting with assault-related injuries on the basis of the record review were compared with those of women who presented for treatment of unintentional injuries. We also assessed the sensitivity and predictive value of nature and anatomic site of injury as markers of assault. RESULTS: We reviewed 8,051 records, of which 2,966 (37%) involved an injury at presentation. Two hundred sixty patients (9%) were identified as victims of assault. Of those women who presented with assault-related injuries and had known assailants, most were likely injured by a partner or former partner. Women with assault-related injuries were more likely to be younger and of Maori or Pacific Islands origin. They were also more likely to present between the hours of 6 PM and 6 AM on Friday, Saturday, or Sunday and to have a greater history of prior presentations to the emergency department. Compared with patients who presented with unintentional injuries, women with assault-related injuries had a greater likelihood of presenting with contusions (odds ratio, 3.54; 95% confidence interval, 2.57 to 4.88); ill-defined signs and symptoms (odds ratio, 3.20; 95% confidence interval, 1.95 to 5.24); internal injuries (odds ratio, 2.48; 95% confidence interval, 1.46 to 4.18); fractures of the head, spine, or trunk (odds ratio, 2.09; 95% confidence interval, 1.23 to 3.53); and open wounds (odds ratio, 1.90; 95% confidence interval, 1.39 to 2.61). Assault-related injuries most commonly involved the head (odds ratio, 12.8; 95% confidence interval, 9.33 to 17.68). Despite the strength of these associations, however, with regard to nature of injury the sensitivity and positive predictive value of these indicators were limited (sensitivity < or = 26.5%, positive predictive value < or = 24.3%). The maximum sensitivity for anatomic site as a marker for assault was found for injuries to the head (63.7%), but the positive predictive value was still low at 35.7%. Women with assault-related injuries were more likely than women with unintentional injuries to be discharged from the emergency department without referral for follow-up treatment and were more likely to leave the department without completing treatment. CONCLUSION: Women identified as presenting with assault-related injuries differ from those who present with unintentional injuries in terms of their demographic and presentation characteristics, as well as the nature, anatomic site of injury, and follow-up treatment for injuries. Although some of this information has implications for service delivery to abused women, the use of clinical indicators such as nature and anatomic site of injury have limited predictive value. Therefore we recommend that health care providers routinely screen patients for assault, particularly assault by intimate partners, so that they may respond appropriately by providing better treatment and referral.

Randomised controlled trial of a general practice programme of home based exercise to prevent falls in elderly women.

OBJECTIVE: To assess the effectiveness of a home exercise programme of strength and balance retraining exercises in reducing falls and injuries in elderly women. DESIGN: Randomised controlled trial of an individually tailored programme of physical therapy in the home (exercise group, n = 116) compared with the usual care and an equal number of social visits (control group, n = 117). SETTING: 17 general practices in Dunedin, New Zealand. SUBJECTS: Women aged 80 years and older living in the community and registered with a general practice in Dunedin. MAIN OUTCOME MEASURES: Number of falls and injuries related to falls and time between falls during one year of follow up; changes in muscle strength and balance measures after six months. RESULTS: After one year there were 152 falls in the control group and 88 falls in the exercise group. The mean (SD) rate of falls was lower in the exercise than the control group (0.87 (1.29) v 1.34 (1.93) falls per year respectively; difference 0.47; 95% confidence interval 0.04 to 0.90). The relative hazard for the first four falls in the exercise group compared with the control group was 0.68 (0.52 to 0.90). The relative hazard for a first fall with injury in the exercise group compared with the control group was 0.61 (0.39 to 0.97). After six months, balance had improved in the exercise group (difference between groups in change in balance score 0.43 (0.21 to 0.65). CONCLUSIONS: An individual programme of strength and balance retraining exercises improved physical function and was effective in reducing falls and injuries in women 80 years and older.

Nonfatal firearm injuries in New Zealand, 1979-1992.

STUDY OBJECTIVE: To describe the epidemiology of serious non-fatal firearm injury in New Zealand. METHODS: Cases of nonfatal firearm-related injury were extracted from the hospital inpatient data files of the New Zealand Health Information Service for the period 1979 to 1992 inclusive. RESULTS: There were 1,239 firearm-related injuries, or 2.7 injuries per 100,000 population per year. Males, persons aged 15 to 24 years, certain occupational groups, and persons living in rural environments had higher rates of injury. Unintentional incidents accounted for 64% of the injuries. At least 25% of the incidents involved shotguns, and a further 20% involved rifles. CONCLUSION: The results presented here serve to support the attention that has been given to prevention of firearm injuries in New Zealand. Priority should be given to establishment of a surveillance system that would provide uniform data on firearm-related mortality and morbidity to aid in risk factor research and development and evaluation of intervention programs.

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.

Motor vehicle occupant injuries in New Zealand children, 1981-90.

AIM: To determine the incidence of motor vehicle occupant injuries in New Zealand children and to consider future directions for prevention. METHODS: The Ministry of Health's national mortality and morbidity files for the years 1981-1990 were examined to identify all deaths and hospital discharges for motor vehicle occupant injuries in children between the ages of 0-14 years. RESULTS: Over the 10 year period, there was an average of 26 deaths and 433 hospitalisations annually. Fatality rates were highest for the age group 0-2 years, whereas hospitalisation rates were highest for those aged 3-4 years. Although mortality rates were similar for Maori and nonMaori children, the hospitalisation rate for Maori children was more than three times that for nonMaori children. No significant trends in either fatality or hospitalisation rates were evident. DISCUSSION: Motor vehicle occupant injury is an important public health problem in New Zealand children. Reductions in the numbers of motor vehicle occupant deaths and hospitalisations will require not only legislative changes aimed at increasing restraint use, but also the development of strategies to ensure compliance with the legislation. The identification of barriers to the use of child restraints is likely to facilitate the development of effective strategies aimed at increasing occupant restraint use.

Injury surveillance in public hospital emergency departments.

AIMS: To identify existing surveillance initiatives and to seek and reach consensus on a national minimum data set for injury surveillance in public hospital emergency departments in New Zealand. METHODS: Every public hospital emergency department was visited to obtain information on current surveillance initiatives. At the same time, guidelines for a national minimum data set for injury surveillance were considered. National organisations who might use the information were contacted and also asked to consider the guidelines. RESULTS: Of the 43 public hospital emergency departments visited, five had on-site computerised information systems, the majority collecting data manually. Basic demographic data and information in a narrative form were the only data recorded consistently by all hospitals. A national minimum data set for injury surveillance was adopted by general agreement at a consensus forum, held in Wellington, in March, 1992. Current developments indicate that the minimum data set for injury surveillance, as adopted at the forum will become a component of the National Minimum Data Set within the proposed Health Information Strategy for New Zealand. CONCLUSIONS: Injury data collection will, in time become mandatory. However, the promotion of the minimum data set for injury surveillance by health professionals, national organisations and community groups will be essential to ensure its implementation and utilisation for the prevention and control of injuries.

Mortality from interpersonal violence in Great Britain.

Data accessed from both death certificates and police reports show that mortality from interpersonal violence is extremely uncommon in Great Britain, particularly in comparison with other countries; in 1985, it accounted for only 0.1 per cent of all deaths and 0.4 per cent of deaths among individuals under 65 years of age. Despite a steady increase in the rate of homicide over the past 20 years, homicide can only be considered to be a minor public health issue in Great Britain. In contrast, data accessed from the British Crime Surveys and from studies conducted both in accident and emergency departments and among individuals hospitalized with head injuries, show that morbidity associated with interpersonal violence may be relatively common in Great Britain. However, until more valid estimates of morbidity can be made, the overall importance of interpersonal violence as a public health issue in Great Britain cannot be assessed with accuracy.

The role of alcohol in mortality and morbidity from interpersonal violence.

Alcohol is regarded widely as a causal factor in interpersonal violence in Great Britain. However, much of the evidence used to support this association is anecdotal, or at best, based on descriptive studies. Data calculated from cross-sectional, case-control and cohort studies, undertaken in Great Britain, show that individuals who consume alcohol are several times more likely to perpetrate violence, or to be the victims of violence, than individuals who do not consume alcohol. If criteria for causality are used to assess these findings, then it would appear that alcohol is likely to be a causal factor in both violence perpetration and violence victimization. However, the proportion of interpersonal violence caused by alcohol and the levels of alcohol consumption associated with significantly increased risks of involvement in interpersonal violence cannot be identified from the data available to date.

Improving information on the role of alcohol in interpersonal violence in Great Britain.

In Great Britain, at present, no valid or reliable estimate can be made of the proportion of interpersonal violence caused by alcohol, nor can an assessment be made of the levels of alcohol consumption associated with an increased risk of involvement in interpersonal violence. A critical review of existing British studies and surveillance systems has been undertaken, which indicates that the role of alcohol in interpersonal violence could be defined more precisely, if new and better analytical studies were conducted, if ongoing logitudinal studies and existing surveillance systems were improved or better exploited, and if new surveillance systems were implemented.