New Zealand's Prospective Outcomes of Injury Study-10 years on (POIS-10): descriptive outcomes to 12 years post-injury.

BACKGROUND: The 'Prospective Outcomes of Injury Study-10 years on' (POIS-10) aims to contribute to improving long-term disability, health and well-being outcomes for injured New Zealanders. This brief report describes recruitment, characteristics and key outcomes to 12 years post-injury. METHODS: Between 2007 and 2009, the study recruited 2856 people, including 566 Maori, from New Zealand's Accident Compensation Corporation's entitlement claims register. People experienced a range of injury types, causes and settings; 25% had been hospitalised for their injury. POIS-10 data were primarily collected via interviewer-administered structured questionnaires. RESULTS: Of the original participants, 2068 (92%) were eligible for follow-up in POIS-10. Of these, 1543 (75%) people participated between March 2020 and July 2021, including 240 Maori. Half of the participants (n=757; 50%) reported ongoing problems attributed to their injury 12 years earlier. Most reported difficulties with items assessing disability (WHO Disability Assessment Schedule II). For health-related quality of life (HRQoL), measured using the EQ-5D-5L, the prevalence of problems was higher 12 years post-injury compared with 12 months post-injury for four of five dimensions. Importantly, the prevalence of problems did not reduce to pre-injury levels for any HRQoL dimension. DISCUSSION: POIS-10 highlights the importance of early post-injury interventions to improve health, disability and well-being outcomes of injured New Zealanders.

Life satisfaction 18 months and 10 years following spinal cord injury: results from a New Zealand prospective cohort study.

PURPOSE: To examine the life satisfaction outcomes after spinal cord injury (SCI) and to identify the factors associated with life satisfaction at 18 months and 10 years post-SCI in New Zealand (NZ). METHODS: Adults (16-64 years) were recruited between 2007 and 2009 from NZ's two spinal units following first admission for SCI. Interviews at 6 months, 18 months, and 10 years post-SCI examined demographic, physical, psychosocial, economic, and environmental characteristics. Multivariable regression models were used to identify predictors of life satisfaction at each timepoint. RESULTS: Overall, 118 people participated at 6 months, 103 at 18 months, and 63 at 10 years post-SCI. Pre-SCI, 90% of participants were satisfied with life, 67% were satisfied at 18 months, and 78% at 10 years. At 18 months post-SCI, participants who reported: never or sometimes using a wheelchair, no problems with self-care, no problems with anxiety or depression, no/lesser disability, or fewer secondary health conditions (SHCs) at 6 months post-SCI were more likely to be satisfied (p < 0.05), compared to those without these characteristics. Participants who experienced considerable disability at 6 months post-SCI were 22% less likely to be satisfied 10 years post-SCI compared to those experiencing no/lesser disability (p = 0.028). CONCLUSIONS: A higher proportion of participants were satisfied at both 18 months and 10 years post-SCI than not satisfied. To improve the likelihood of satisfaction with life, increased focus on reducing disability and providing supports for those using wheelchairs, experiencing anxiety/depression or problems with self-care, and effects of SHCs are promising for future potential interventions.

Predictors of EQ-5D-3L outcomes amongst injured Maori: 1-year post-injury findings from a New Zealand cohort study.

PURPOSE: Maori, the Indigenous population of New Zealand (NZ), are at higher risk of problems with health-related quality of life (HRQoL) 12 months following injury. This paper examines pre-injury sociodemographic and health characteristics and injury-related factors, including healthcare access, and their association with HRQoL outcomes 12 months after injury. METHODS: The Prospective Outcomes of Injury Study recruited 2856 injured New Zealanders aged 18-64 years from the entitlement claims register of the country's no-fault injury insurance agency. One-fifth (n = 566) of the cohort were Maori. Information on predictors and outcomes, with the exception of injury and hospitalisation, was obtained directly from participants at approximately 3 and 12 months post-injury. The outcomes of interest were responses to the five dimensions of the EQ-5D-3L and a dichotomous measure obtained by summing scored responses to each question. Modified Poisson regression was used to identify predictors of each outcome at 12 months post-injury. RESULTS: Predictors differed by outcome. Being female, experiencing EQ-5D-3L problems pre-injury, having ≥ 2 chronic conditions pre-injury, perceiving one's injury to be a threat of long-term disability, and having trouble accessing health services for injury were common predictors of EQ-5D-3L problems at 12 months post-injury for Maori. CONCLUSION: Opportunities exist to improve HRQoL outcomes by identifying individuals in the early stages of injury recovery who may benefit from further treatment and support.

Missing cases of injury death: use of quantitative methods and case reviews to inform future improvements in case definition.

BACKGROUND: Knowledge of fatal injuries is required to inform prevention activities. Where hospital patients with an injury principal diagnosis (PDx) died and were certified to a medical underlying cause of death (UCoD), there is the potential to underestimate injury mortality. We sought to characterise injury/non-injury (NI) mismatches between PDx and UCoD by identifying which subgroups had small/large mismatches, and to understand why mismatches had occurred using informative examples. METHOD: Hospital records (n=10 234) with a PDx of injury were linked to the mortality collection using a unique personal identifier. Percentages UCoD coded to a NI were tabulated, for three follow-up periods and by selected variables. Additionally, we reviewed a sample of 70 records for which there was a mismatch. RESULTS: %NIs were 39%, 66% and 77% for time from injury to death of <1 week, <90 days and <1 year, respectively. Variations in %NI were found for all variables. Illustrative examples of 70 medical UCoD deaths showed that for 12 cases the injury event was unequivocally judged to have resulted in premature death. A further 16 were judged as injury deaths using balance of probability arguments. CONCLUSION: There is variation in rates of mismatch between PDx of injury and UCoD of NI. While legitimate reasons exist for mismatches in certain groups, a material number of injury deaths are not captured using UCoD alone; a new operational definition of injury death is needed. Early solutions are proposed. Further work is needed to investigate operational definitions with acceptable false positive and negative detection rates.

Prevalence and predictors of post-traumatic stress symptoms in 2200 hospitalised and non-hospitalised injured New Zealanders.

OBJECTIVE: Post-traumatic stress disorder following injuries unrelated to mass casualty events has received little research attention in New Zealand. Internationally, most studies investigating predictors of post-injury post-traumatic stress disorder focus on hospitalised patients although most survivors are not hospitalised. We compared the prevalence and predictors of symptoms suggestive of post-traumatic stress disorder 12 months following injury among hospitalised and non-hospitalised entitlement claimants in New Zealand's Accident Compensation Corporation. This government-funded universal no-fault insurance scheme replaced tort-based compensation for injuries in 1974 since when civil litigation (which can bias post-traumatic stress disorder estimates) has been rare. METHODS: A total of 2220 Accident Compensation Corporation claimants aged 18-64 years recruited to the Prospective Outcomes of Injury Study were interviewed at 12 months post-injury to identify symptoms suggestive of post-traumatic stress disorder using the Impact of Events Scale. Multivariable models examined the extent to which baseline sociodemographic, injury, health status and service interaction factors predicted the risk of post-traumatic stress disorder symptoms among hospitalised and non-hospitalised groups. RESULTS: Symptoms suggestive of post-traumatic stress disorder were reported by 17% of hospitalised and 12% of non-hospitalised participants. Perceived threat to life at the time of the injury doubled this risk among hospitalised (adjusted relative risk: 2.0; 95% confidence interval: 1.2-3.2) and non-hospitalised (relative risk: 1.8; 95% confidence interval: 1.2-2.8) participants. Among hospitalised participants, other predictors included female gender, Pacific and 'other' minority ethnic groups, pre-injury depressive symptoms, financial insecurity and perceived inadequacies in healthcare interactions, specifically information and time to discuss problems. Among non-hospitalised survivors, predictors included smoking, hazardous drinking, assault and poor expectations of recovery. CONCLUSION: One in six hospitalised and one in eight non-hospitalised people reported post-traumatic stress disorder symptoms 12 months following injury. Perceived threat to life was a strong predictor of this risk in both groups. Identifying early predictors of post-traumatic stress disorder, regardless of whether the injury required hospitalisation, could help target tailored interventions that can reduce longer-term psychosocial morbidity.

Predictors of subsequent injury at work: findings from a prospective cohort of injured workers in New Zealand.

OBJECTIVES: People who have experienced a work-related injury can experience further work injuries over time. This study examines predictors of subsequent work-related injuries over 24 months among a cohort of injured workers. METHODS: Participants were those recruited to the earlier Prospective Outcomes of Injury Study (POIS) who had a work-related injury (the 'sentinel' injury). Data from POIS participant interviews were combined with administrative data from the Accident Compensation Corporation (New Zealand's no-fault universal injury insurer) and hospital discharge data. Modified Poisson regression modelling was used to examine whether presentinel injury sociodemographic and health, sentinel injury or presentinel injury work-related factors predicted subsequent work-related injuries. RESULTS: Over a third of participants (37%) had at least one subsequent work-related injury in 24 months. Factors associated with an increased risk of work-related subsequent injury included being in a job involving carrying or moving heavy loads more than half the time compared with those in jobs that never involved such tasks (RR 1.42, 95% CI 1.01 to 2.01), having an inadequate household income compared with those with an adequate household income (RR 1.33, 95% CI 1.02 1.74) and being aged 50-64 years compared with those aged 30-49 years (RR 1.25, 95% 1.00 to 1.57). CONCLUSION: Subsequent work-related injuries occur frequently, and presenting with a work-related injury indicates a potentially important intervention point for subsequent injury prevention. While the strength of associations were not strong, factors identified in this study that showed an increased risk of subsequent work-related injuries may provide a useful focus for injury prevention or rehabilitation attention.

Use of mixed methods to investigate case definitions to improve the identification of serious injury cases from hospital episode data.

INTRODUCTION: It has been commonplace internationally, when using hospital data, to use the principal diagnosis to identify injury cases and the first external cause of injury code (E-code) to identify the main cause. Our purpose was to investigate alternative operational definitions of serious non-fatal injury to identify cases of interest for injury surveillance, both overall and for four common causes of injury. METHODS: Serious non-fatal injury cases were identified from New Zealand (NZ) hospital discharge data using an alternative definition: that is, case selection using principal and additional diagnoses. Separately, identification of cause used all E-codes on the discharge record. Numbers of cases identified were contrasted with those captured using the usual definition. Views of NZ government stakeholders were sought regarding the acceptability of the additional cases found using these alternative definitions. Views of international experts were also canvassed. RESULTS: When using all diagnoses there was a 7% increase in 'all injury' cases identified, a 17% increase in self-harm cases and 8% increase in falls cases. Use of all E-codes resulted in a 4% increase in self-harm cases, 2% increase in assault cases and 1% increase in both falls and motor vehicle traffic crash cases. DISCUSSION: A case definition based solely on principal diagnosis fails to count a material number of serious non-fatal injury cases that are of interest to the injury prevention community. There is a need, therefore, to use an alternative case definition that includes additional diagnoses. Use of multiple E-codes to classify cause of injury should be considered.

Recruitment and participant baseline characteristics in the dialysis outcomes in those aged 65 years or older study.

BACKGROUND: Despite an increasing number of older people commencing dialysis the impact of dialysis on their quality of life and survival, remains unclear. The Dialysis Outcomes in those aged over 65 years or older study is an accelerated prospective cohort longitudinal design study, designed to obtain sufficient health related quality of life data, linked to clinical data, to inform clinicians' and patients' decision-making with respect to end stage kidney disease (ESKD), outcomes, and options for management in New Zealand (NZ). METHODS: The study has an accelerated prospective cohort longitudinal design, comprised of cross-sectional and longitudinal components. We report the baseline data on the 225 participants enrolled in the study. Dialysis duration was grouped in tertiles from less than one year (incident patients), 1-3 years and greater than 3 years. Health related quality of life data was obtained from self-reported questionnaires including KDQoL-36, EQ-5D-3 L, FACIT, WHODAS II, and the Personal Well-being Score. RESULTS: The median age of the cohort was 71 years and two thirds were male. Three quarters of the participants were on dialysis at the baseline, with 42% of those on home dialysis (haemodialysis or peritoneal dialysis). Maori and Pacific people were over represented (20% Maori and 24% Pacific) in the sample, when compared to the general NZ population of the same age group (where 5% are Maori and 2% are Pacific). At baseline, there were no differences observed in sociodemographic, quality of life or health characteristics between the dialysis groups either by modality or duration of dialysis. CONCLUSIONS: We report the baseline characteristics of participants enrolled prospectively into a longitudinal cohort observational study examining health related quality of life factors with clinical characteristics on dialysis outcomes in a group of New Zealanders aged 65 years or older who are either on dialysis or have been educated about dialysis (BMC Nephrol 14:175, 2013). Subsequent publications are planned, analysing the prospective longitudinal data to identify key factors that determine both outcome and quality of life for individuals of this age group. TRIAL REGISTRATION: ACTRN12611000024943 .

Seasonal and gestational variation in perinatal depression in a prospective cohort in New Zealand.

BACKGROUND: Perinatal depression has wide-ranging impacts on the health of mothers, babies and their families. Previously published data suggest seasonal variation in the prevalence of perinatal depression, as well as possible variation with gestation. AIMS: To describe the prevalence of perinatal depression in a New Zealand population; to describe the trend in depression over gestational age; and to assess the influence of season on perinatal depression. MATERIALS AND METHODS: We performed a secondary analysis of data from a prospective cohort of 260 women in Dunedin, New Zealand. Edinburgh Depression Scores were collected at four antenatal time points and at six months postpartum. RESULTS: Prevalence of depression decreased from 8.1% to 4.6% antenatally, and to 6.6% postnatally, but the variation was non-significant. Prevalence was significantly higher in winter and spring antenatally (odds ratio (OR) 3.15, 95% CI 1.01-9.82 and OR 3.16, CI 1.05-9.55), and in spring postnatally (OR 8.40, 95% CI 1.01-69.52) compared to autumn. Antenatal depression was associated with poor sleep quality (OR 4.27, 95% CI 1.22-14.93), while postnatal depression was associated with caesarean delivery (OR 5.03, 95% CI 1.29-19.64). CONCLUSIONS: This is the first NZ cohort to assess depression over multiple antenatal and postnatal time points. A significantly higher rate of depression was identified in winter and spring antenatally and in spring postnatally, corresponding to a higher risk of postnatal depression with autumn deliveries. These findings should prompt greater awareness at these higher risk time periods.

Injury upon injury: a prospective cohort study examining subsequent injury claims in the 24 months following a substantial injury.

OBJECTIVES: This study examines subsequent injuries reported to the Accident Compensation Corporation (ACC), New Zealand's universal no-fault injury insurer, in the 24 months following an ACC entitlement claim injury event. Specific aims were to determine the: (1) 12 and 24 month cumulative incidence of at least one ACC-reported subsequent injury (ACC-SUBS-Inj), (2) characteristics of participants with and without ACC-SUBS-Inj, (3) frequency of ACC-SUBS-Inj, (4) time periods in which people are at higher risk of ACC-SUBS-Inj and (5) types of ACC-SUBS-Inj. METHODS: Interview data collected directly from participants in the Prospective Outcomes of Injury Study (POIS) were combined with ACC-SUBS-Inj data from ACC and hospital discharge datasets. A subsequent injury was defined as any injury event resulting in an ACC claim within 24 months following the injury event for which participants were recruited to POIS (the sentinel injury). All ACC-SUBS-Inj were included irrespective of whether they were the same as the sentinel injury or not. RESULTS: Of 2856 participants, 58% (n=1653) experienced at least one ACC-SUBS-Inj in 24 months; 31% (n=888) had more than one ACC-SUBS-Inj. The time period of lowest risk of ACC-SUBS-Inj was the first 3 months following the sentinel injury event. Spine sprain/strain was the type of injury with the greatest number of ACC-SUBS-Inj claims per person. CONCLUSIONS: More than half of those with an ACC entitlement claim injury incurred further injury events that resulted in a claim in the following 24 months. Greater understanding of these subsequent injury events provides an avenue for injury prevention.

Predictors of Health Deterioration Among Older Adults After 12 Months of Dialysis Therapy: A Longitudinal Cohort Study From New Zealand.

BACKGROUND: Involving patients in dialysis decision making is crucial, yet little is known about patient-reported experiences and patient-reported outcomes of dialysis. STUDY DESIGN: A prospective longitudinal cohort study of older patients receiving long-term dialysis. Predictors of worse health status were assessed using modified Poisson regression analysis. SETTING & PARTICIPANTS: 150 New Zealanders 65 years or older with end-stage kidney disease dialyzing at 1 of 3 nephrology centers. PREDICTORS: Patient-reported social and health characteristics based on the 36-Item Short Form Health Survey, EQ-5D, and Kidney Symptom Score questionnaires and clinical information from health records. OUTCOMES: Health status after 12 months of follow-up. RESULTS: 35% of study participants had reported worse health or had died at 12 months. Baseline variables independently associated with reduced risk for worse health status were Pacific ethnicity (relative risk [RR], 0.63; 95% CI, 0.53-0.72), greater bother on the Kidney Symptom Score (RR, 0.78; 95% CI, 0.62-0.97), and dialyzing at home with either home hemodialysis (RR, 0.55; 95% CI, 0.36-0.83) or peritoneal dialysis (RR, 0.86; 95% CI, 0.79-0.93). Baseline variables independently associated with increased risk were greater social dissatisfaction (RR, 1.66; 95% CI, 1.27-2.17), lower sense of community (RR, 1.70; 95% CI, 1.09-2.64), comorbid conditions (RR, 1.70; 95% CI, 1.09-2.64), EQ-5D anxiety/depression (RR, 1.61; 95% CI, 1.07-2.42); poor/fair overall general health (RR, 1.60; 95% CI, 1.37-1.85), and longer time on dialysis therapy (RR, 1.03; 95% CI, 1.00-1.05). LIMITATIONS: Small sample size restricted study power. CONCLUSIONS: Most older dialyzing patients studied reported same/better health 12 months later. Home-based dialysis, regardless of whether hemodialysis or peritoneal dialysis, was associated with reduced risk for worse health, and older Pacific People reported better outcomes on dialysis therapy. Social and/or clinical interventions aimed at improving social satisfaction, sense of community, and reducing anxiety/depression may favorably affect the experiences of older patients receiving long-term dialysis.

Subsequent Injury Study (SInS): Improving outcomes for injured New Zealanders.

BACKGROUND: Subsequent injury (SI) is a major contributor to disability and costs for individuals and society. AIM: To identify modifiable risk factors predictive of SI and SI health and disability outcomes and costs. OBJECTIVES: To (1) describe the nature of SIs reported to New Zealand's no-fault injury insurer (the Accident Compensation Corporation (ACC)); (2) identify characteristics of people underaccessing ACC for SI; (3) determine factors predicting or protecting against SI; and (4) investigate outcomes for individuals, and costs to society, in relation to SI. DESIGN: Prospective cohort study. METHODS: Previously collected data will be linked including data from interviews undertaken as part of the earlier Prospective Outcomes of Injury Study (POIS), ACC electronic data and national hospitalisation data about SI. POIS participants (N=2856, including 566 Maori) were recruited via ACC's injury register following an injury serious enough to warrant compensation entitlements. We will examine SI over the following 24 months for these participants using descriptive and inferential statistics including multivariable generalised linear models and Cox's proportional hazards regression. DISCUSSION: Subsequent Injury Study (SInS) will deliver information about the risks, protective factors and outcomes related to SI for New Zealanders. As a result of sourcing injury data from New Zealand's 'all injury' insurer ACC, SInS includes people who have been hospitalised and not hospitalised for injury. Consequently, SInS will provide insights that are novel internationally as other studies are usually confined to examining trauma registries, specific injuries or injured workers who are covered by a workplace insurer rather than a 'real-world' injury population.

The impact of a rural scanner in overcoming urban versus rural disparities in the utilisation of computed tomography.

OBJECTIVE: In 2008, Oamaru Hospital became the second rural hospital in New Zealand to install a computed tomography (CT) scanner. This article assesses the impact of this on local CT scanning rates. DESIGN: Observational: review of radiology department data. SETTING: Rural hospital imaging services. PARTICIPANTS: CT scanning patients residing in Otago region during the study period. INTERVENTIONS: There is no intervention in this observational study. MAIN OUTCOME MEASURES: CT scanning rates and waiting times before and after the introduction of the rural scanner. RESULTS: Prior to the scanner being commissioned, there was a significant urban versus rural disparity in CT utilisation. Residents in the neighbouring urban centre were 1.4 times more likely to access CT (33.2 (95% confidence interval (CI) 32.2-34.2) versus 23.0 (95% CI 21.0-25.1) scans per 1000 residents per annum). Twenty months after the scanner was commissioned, the rate for the rural community had almost doubled to 45.6 (95% CI 43.0-48.2) and was 1.2 times greater than for the urban community. This difference was not sustained, and rural and urban communities had similar CT scanning rates in 2011 and 2012. Mean waiting time for residents in the rural community fell from 21.1 (95% CI 17.1-25.2) days prior to the scanner to 6.7 (95% CI 5.6-7.8) days after the scanner was commissioned. CONCLUSIONS: On-site CT increased the rural scanning rate, corrected the rural-urban disparity and reduced waiting times without apparent over servicing.

Factors predictive of subsequent injury in a longitudinal cohort study.

OBJECTIVES: The aims are to: (1) Determine the cumulative incidence of self-reported subsequent injury (of any anatomical site or injury type) occurring between 3 months and 12 months after a sentinel injury among participants in the Prospective Outcomes of Injury Study in New Zealand and (2) Examine the preinjury and injury-related predictors of subsequent injury. METHODS: Prospective Outcomes of Injury Study participants (n=2282) were interviewed 3 months, 5 months and 12 months after a sentinel injury event. Data were collected about a range of preinjury and injury-related factors at the 3-month interview and about subsequent injury at the 5-month and 12-month interviews. Poisson regression modelling was used to determine the preinjury and injury-related predictors of subsequent injury. RESULTS: Between the 3-month and 12 month interviews 28% of the participants reported at least one subsequent injury. Subsequent injury was 34% more likely among participants with a prior injury affecting them at the time of the sentinel injury compared with participants without a prior injury affecting them, and more likely among non-workers (31% more likely) and trade/manual workers (32% more likely) compared with professionals. Participants whose sentinel injury was due to assault were 43% more likely to report a subsequent injury compared with those whose sentinel injury was accidental. A subsequent injury was 23% less likely if the sentinel injury was a lower extremity fracture compared with other injuries, and 21% less likely if the sentinel injury event involved hospitalisation. CONCLUSIONS: Among general injury populations it may be possible to identify people at increased risk for subsequent injury.

Prevalence of poor outcomes soon after injury and their association with the severity of the injury.

Little is known of injury outcomes among non-hospitalised injured populations. This study examined the occurrence of poor outcomes 3 months after injury among the 2856 participants in the Prospective Outcomes of Injury Study, most of whom had sustained injuries considered of minor severity (by injury severity scoring) and had not received treatment at a hospital facility. The prevalence of poor outcomes was high across all health, physical functioning and social functioning domains and expectation characteristics examined, including for those participants with the 'least severe' injuries. Approximately half of the cohort reported experiencing moderate to high pain or psychological distress and reduced social participation, and three-quarters did not consider themselves recovered. Our findings demonstrate that, to obtain an accurate understanding of injury burden, injury outcome research should not focus only on those injured persons who are hospitalised.

The epidemiology of life-threatening work-related injury--a demonstration paper.

BACKGROUND: Workers' compensation (WC) data traditionally provides information to stakeholders on work-related disabling injuries. It is important to complement this with information on serious threat to life (TTL) injury, which is the focus of this paper. METHODS: In this cross-sectional descriptive epidemiological study, based on New Zealand's WC data linked to hospital discharge data, TTL was measured using the ICD10-based Injury Severity Score (ICISS); ICISS ≤ 0.941 was used to define serious TTL injury. RESULTS: During 2002-2004, there was an average of 368 serious TTL work-related injury cases annually. The distribution of these injuries was very different from those traditionally found using WC data to describe disabling injury. For example, for serious TTL injury the main injury types included traumatic brain injury, whereas for disabling injury it was sprains and dislocations. CONCLUSIONS: The method presented provides the opportunity for government agencies to produce a national description of the epidemiology of serious TTL work-related injuries.

An outcome evaluation of a New Zealand farm safety intervention: a historical cohort study.

BACKGROUND: There is limited evidence that farm safety-related interventions based solely on an educational element have an effect on injury rates. Our aim was to evaluate a New Zealand national educational program, FarmSafe™ Awareness, for its effect on injury rates. METHODS: We used a before-after design followed by a historical cohort study of sheep, beef, and dairy farmers/workers. The outcomes were work-related injuries, identified from workers compensation data. Cox regressions were used to compare intervention with matched control group rates. RESULTS: FarmSafe™ Awareness was associated with significantly higher rates of work-related injury, than matched controls. CONCLUSIONS: It is difficult to see how FarmSafe™ Awareness could be causing an increased rate of work-related injury. We detected no reporting bias, and selection bias is likely to act in the opposite direction to the observed results. We conclude that there is no evidence that FarmSafe™ Awareness prevents farm injury.

Indigenous injury outcomes: life satisfaction among injured Maori in New Zealand three months after injury.

BACKGROUND: Maori, the indigenous population of New Zealand, experience numerous and consistent health disparities when compared to non-Maori. Injury is no exception, yet there is a paucity of published literature that examines outcomes following a wide variety of injury types and severities for this population. This paper aims to identify pre-injury and injury-related predictors of life satisfaction three months after injury for a group of injured Maori. METHODS: The Maori sample (n = 566) were all participants in the Prospective Outcomes of Injury Study (POIS). POIS is a longitudinal study of 2856 injured New Zealanders aged 18-64 years who were on an injury entitlement claims' register with New Zealand's no-fault compensation insurer. The well-known Te Whare Tapa Wha model of overall health and well-being was used to help inform the selection of post-injury life satisfaction predictor variables. Multivariable analyses were used to examine the relationships between potential predictors and life satisfaction. RESULTS: Of the 566 Maori participants, post-injury life satisfaction data was available for 563 (99%) participants. Of these, 71% reported satisfaction with life three months after injury (compared to 93% pre-injury). Those with a higher injury severity score, not satisfied with pre-injury social relationships or poor self-efficacy pre-injury were less likely to be satisfied with life three months after injury. CONCLUSIONS: The large majority of Maori participants reported being satisfied with life three months after injury; however, nearly a third did not. This suggests that further research investigating outcomes after injury for Maori, and predictors of these, is necessary. Results show that healthcare providers could perhaps put greater effort into working alongside injured Maori who have more severe injuries, report poor self-efficacy and were not satisfied with their pre-injury social relationships to ensure increased likelihood of satisfaction with life soon after injury.

Age, period and cohort effects on the incidence of motorcyclist casualties in traffic crashes.

OBJECTIVES: (1) Estimate age, period and cohort effects for motorcyclist traffic casualties 1979-2008 in New Zealand and (2) forecast the incidence of New Zealand motorcycle traffic casualties for the period 2019-2023 assuming future age, cohort and period effects, and compare these with an estimate based on simple linear extrapolation. METHODS: Age-period-cohort (APC) modelling was used to estimate the individual effects of age, period and cohort after adjusting for the other two factors. Forecasting was produced for three period-effect scenarios. RESULTS: After adjusting for cohort and period effects, 15-19-year-olds have substantially elevated risk. The period effect reduced in significance over time until the last period, 2004-2008, where the risk was higher than the preceding period. The 10-year cohorts born 1949-1958, 1954-1963, 1959-1968 and 1964-1973, had elevated risk. The forecasting, based on APC modelling, resulted in the lowest estimates of the future incidence being approximately one-third that of the highest estimate (6641). CONCLUSION: Trends in motorcycle casualties have been influenced by significant independent age, period and cohort effects. These need to be considered in forecasting future casualties. The selection of the period effect has a significant impact on the estimates. Which period-effect scenario readers choose to accept depends on their views about a wide range of factors which might influence motorcycle use and crash risk over time.

Factors associated with non-participation in one or two follow-up phases in a cohort study of injured adults.

OBJECTIVE: To identify factors associated with non-participation at the 12-month and 24-month follow-up phases of a prospective cohort study of injury outcomes. METHODS: Associations between non-participation at follow-up phases and a range of sociodemographic, injury, health, outcome and administrative factors were examined. RESULTS: An individual's non-participation at 12 months did not necessarily mean non-participation at 24 months. Sociodemographic factors were the most salient for non-participation, regardless of the number of follow-up phases or specific phase considered. CONCLUSIONS: Retention rates in prospective cohort studies of injury outcome may be improved by follow-up of everyone irrespective of previous non-participation, focusing resources to retain men, young adults, indigenous people and those living with people other than family members, and by ensuring that multiple alternative participant contacts are obtained. There is sufficient evidence to be concerned about potential bias given that several of the factors we, and others, have identified as associated with non-participation are also associated with various functional and disability outcomes following injury. This suggests detailed investigations are warranted into the effect non-participation may be having on the estimates for various outcomes.