Environmental burden of disease from unsafe and substandard housing, New Zealand, 2010-2017.

OBJECTIVE: To assess the burden of disease related to unsafe and substandard housing conditions in New Zealand from 2010 to 2017. METHODS: We focused on substandard housing conditions most relevant for New Zealand homes: crowding, cold, damp or mould, and injury hazards linked to falls. We estimated the population attributable fraction using existing estimates of the population exposed and exposure-response relationships of health disorders associated with each housing condition. We used government hospitalization data, no-fault accident insurance claims and mortality data to estimate the annual disease burden from the most severe cases, as well as the resulting costs to the public sector in New Zealand dollars (NZ$). Using value of a statistical life measures, we estimated the indirect cost of deaths. FINDINGS: We estimated that illnesses attributable to household crowding accounted for 806 nights in hospital annually; cold homes for 1834 hospital nights; and dampness and mould for 36 649 hospital nights. Home injury hazards resulted in 115 555 annual accident claims. We estimated that direct public sector costs attributable to these housing conditions were approximately NZ$ 141 million (100 million United States dollars, US$) annually. We also estimated a total of 229 deaths annually attributable to adverse housing and the costs to society from these deaths at around NZ$ 1 billion (US$ 715 million). CONCLUSION: Of the conditions assessed in this study, damp and mouldy housing accounted for a substantial proportion of the burden of disease in New Zealand. Improving people's living conditions could substantially reduce total hospitalization costs and potentially improve quality of life.

Damp mouldy housing and early childhood hospital admissions for acute respiratory infection: a case control study.

INTRODUCTION: A gap exists in the literature regarding dose-response associations of objectively assessed housing quality measures, particularly dampness and mould, with hospitalisation for acute respiratory infection (ARI) among children. METHODS: A prospective, unmatched case-control study was conducted in two paediatric wards and five general practice clinics in Wellington, New Zealand, over winter/spring 2011-2013. Children aged <2 years who were hospitalised for ARI (cases), and either seen in general practice with ARI not requiring admission or for routine immunisation (controls) were included in the study. Objective housing quality was assessed by independent building assessors, with the assessors blinded to outcome status, using the Respiratory Hazard Index (RHI), a 13-item scale of household quality factors, including an 8-item damp-mould subscale. The main outcome was case-control status. Adjusted ORs (aORs) of the association of housing quality measures with case-control status were estimated, along with the population attributable risk of eliminating dampness-mould on hospitalisation for ARI among New Zealand children. RESULTS: 188 cases and 454 controls were studied. Higher levels of RHI were associated with elevated odds of hospitalisation (OR 1.11/unit increase (95% CI 1.01 to 1.21)), which weakened after adjustment for season, housing tenure, socioeconomic status and crowding (aOR 1.04/unit increase (95% CI 0.94 to 1.15)). The damp-mould index had a significant, adjusted dose-response relationship with ARI admission (aOR 1.15/unit increase (95% CI 1.02 to 1.30)). By addressing these harmful housing exposures, the rate of admission for ARI would be reduced by 19% or 1700 fewer admissions annually. CONCLUSIONS: A dose-response relationship exists between housing quality measures, particularly dampness-mould, and young children's ARI hospitalisation rates. Initiatives to improve housing quality and to reduce dampness-mould would have a large impact on ARI hospitalisation.

Physical Activity Prevalence and Correlates Among New Zealand Older Adults.

The aim of this study was to provide up-to-date information about physical activity (PA) levels in New Zealand older adults to inform the development and targeting of relevant health promotion initiatives. Nationally-representative survey (N = 1,468) data were analyzed to assess in people aged ≥ 60 years the prevalence of physical inactivity and meeting PA guidelines, differences between 2012 and 2014, and sociodemographic correlates. One-fifth (20.7%) of respondents were inactive; 46.2% met PA guidelines. Multivariate analyses revealed lower PA in 2014 versus 2012, and identified self-rated health and education as correlates of both PA measures. Age and socioeconomic deprivation were associated with physical inactivity only, while sex and employment were correlates of meeting PA guidelines. Low PA among older adults signals a need to promote PA engagement in that age group. This analysis aids effective intervention design by identifying specific segments of the older adult population that tailored health promotion initiatives should target.

Cost-benefit analysis of fall injuries prevented by a programme of home modifications: a cluster randomised controlled trial.

BACKGROUND: Injuries due to falls in the home impose a huge social and economic cost on society. We have previously found important safety benefits of home modifications such as handrails for steps and stairs, grab rails for bathrooms, outside lighting, edging for outside steps and slip-resistant surfacing for outside areas such as decks. Here we assess the economic benefits of these modifications. METHODS: Using a single-blinded cluster randomised controlled trial, we analysed insurance payments for medically treated home fall injuries as recorded by the national injury insurer. The benefits in terms of the value of disability adjusted life years (DALYs) averted and social costs of injuries saved were extrapolated to a national level and compared with the costs of the intervention. RESULTS: An intention-to-treat analysis was carried out. Injury costs per time exposed to the modified homes compared with the unmodified homes showed a reduction in the costs of home fall injuries of 33% (95% CI 5% to 49%). The social benefits of injuries prevented were estimated to be at least six times the costs of the intervention. The benefit-cost ratio can be at least doubled for older people and increased by 60% for those with a prior history of fall injuries. CONCLUSIONS: This is the first randomised controlled trial to examine the benefits of home modification for reducing fall injury costs in the general population. The results show a convincing economic justification for undertaking relatively low-cost home repairs and installing safety features to prevent falls. TRIAL REGISTRATION NUMBER: ACTRN12609000779279.

Home modifications to reduce injuries from falls in the home injury prevention intervention (HIPI) study: a cluster-randomised controlled trial.

BACKGROUND: Despite the considerable injury burden attributable to falls at home among the general population, few effective safety interventions have been identified. We tested the safety benefits of home modifications, including handrails for outside steps and internal stairs, grab rails for bathrooms, outside lighting, edging for outside steps, and slip-resistant surfacing for outside areas such as decks and porches. METHODS: We did a single-blind, cluster-randomised controlled trial of households from the Taranaki region of New Zealand. To be eligible, participants had to live in an owner-occupied dwelling constructed before 1980 and at least one member of every household had to be in receipt of state benefits or subsidies. We randomly assigned households by electronic coin toss to either immediate home modifications (treatment group) or a 3-year wait before modifications (control group). Household members in the treatment group could not be masked to their assigned status because modifications were made to their homes. The primary outcome was the rate of falls at home per person per year that needed medical treatment, which we derived from administrative data for insurance claims. Coders who were unaware of the random allocation analysed text descriptions of injuries and coded injuries as all falls and injuries most likely to be affected by the home modifications tested. To account for clustering at the household level, we analysed all injuries from falls at home per person-year with a negative binomial generalised linear model with generalised estimating equations. Analysis was by intention to treat. This trial is registered with the Australian New Zealand Clinical Trials Registry, number ACTRN12609000779279. FINDINGS: Of 842 households recruited, 436 (n=950 individual occupants) were randomly assigned to the treatment group and 406 (n=898 occupants) were allocated to the control group. After a median observation period of 1148 days (IQR 1085-1263), the crude rate of fall injuries per person per year was 0.061 in the treatment group and 0.072 in the control group (relative rate 0.86, 95% CI 0.66-1.12). The crude rate of injuries specific to the intervention per person per year was 0.018 in the treatment group and 0.028 in the control group (0.66, 0.43-1.00). A 26% reduction in the rate of injuries caused by falls at home per year exposed to the intervention was estimated in people allocated to the treatment group compared with those assigned to the control group, after adjustment for age, previous falls, sex, and ethnic origin (relative rate 0.74, 95% CI 0.58-0.94). Injuries specific to the home-modification intervention were cut by 39% per year exposed (0.61, 0.41-0.91). INTERPRETATION: Our findings suggest that low-cost home modifications and repairs can be a means to reduce injury in the general population. Further research is needed to identify the effectiveness of particular modifications from the package tested. FUNDING: Health Research Council of New Zealand.

An analysis of changes in mobility and safety of older drivers associated with a specific older driver on-road licensing test: a population study.

BACKGROUND: From 1999 to the end of 2006, older drivers aged 80 plus in New Zealand were subject to an older driver licence test as a condition of licensing. The impact of this test has not yet been studied in terms of the safety and mobility of older people. METHODS: Three main data sources were analysed to provide evidence of changes in older driver travel mode choice, licensing rates and injuries: New Zealand Travel Survey data, licensing data and police-reported crash data. RESULTS: General trends towards higher levels of motorised mobility were apparent for this group over the 20 years studied, but without an obvious change at the points in time when the test was either introduced or removed as a general requirement of licensure. There were also no apparent changes in the levels of pedestrian activity or road injury involving drivers in this age group. CONCLUSIONS: Along with other relevant studies comparing older driver licensing policies across different jurisdictions, this study does not support the generalised use of on-road testing as an assessment mechanism for all older drivers.

Increasing active travel: aims, methods and baseline measures of a quasi-experimental study.

BACKGROUND: Policy advisers are seeking robust evidence on the effectiveness of measures, such as promoting walking and cycling, that potentially offer multiple benefits, including enhanced health through physical activity, alongside reductions in energy use, traffic congestion and carbon emissions. This paper outlines the 'ACTIVE' study, designed to test whether the Model Communities Programme in two New Zealand cities is increasing walking and cycling. The intervention consists of the introduction of cycle and walkway infrastructure, along with measures to encourage active travel. This paper focuses on the rationale for our chosen study design and methods. METHOD: The study design is multi-level and quasi-experimental, with two intervention and two control cities. Baseline measures were taken in 2011 and follow-up measures in 2012 and 2013. Our face-to-face surveys measured walking and cycling, but also awareness, attitudes and habits. We measured explanatory and confounding factors for mode choice, including socio-demographic and well-being variables. Data collected from the same households on either two or three occasions will be analysed using multi-level models that take account of clustering at the household and individual levels. A cost-benefit analysis will also be undertaken, using our estimates of carbon savings from mode shifts. The matching of the intervention and control cities was quite close in terms of socio-demographic variables, including ethnicity, and baseline levels of walking and cycling. DISCUSSION: This multidisciplinary study provides a strong design for evaluating an intervention to increase walking and cycling in a developed country with relatively low baseline levels of active travel. Its strengths include the use of data from control cities as well as intervention cities, an extended evaluation period with a reasonable response rate from a random community survey and the availability of instrumental variables for sensitivity analyses.

Adjusting vehicle secondary safety ratings to account for crash-avoidance technology fitment using real-world crash and injury data.

OBJECTIVES: Publicizing safety ratings of vehicles can motivate manufacturers to prioritize safety and help consumers choose safer vehicles, leading to safer fleets. The benefits of primary safety technologies that prevent crash occurrence are not currently incorporated in current ratings in a way that values their safety benefits consistently. We aimed to propose a method for assigning weights for each safety technology to account for established safety benefits using published effectiveness and prevalence from real-life data. METHODS: To illustrate this method, we present a worked example calculated using crash and injury data from Australia and New Zealand. The method proposed attenuates the weights for given safety technologies where two or more safety technologies fitted to the same vehicle are effective for the same types of crashes. RESULTS: In the worked example using Australasian data, large SUVs were estimated to have the largest safety increment from the fitment of all the technologies considered compared to vehicles without these primary safety technologies, with an almost 17% reduction in crash occurrence. Cars with all the technologies fitted had estimated average crash reduction of between 11% and 12%. CONCLUSIONS: Different market groups have different crash patterns, so the safety attributable to safety technology fitment differs at the market group level. This study presents an approach for providing a summary measure of crash avoidance according to the fitment of safety technologies. If this measure is combined with an estimate of secondary safety (whether derived from existing crash and injury data or from new car crash assessment programs), the combined estimate then represents the important elements of safety provided by the vehicle. The methods presented here form a rational basis for assigning safety ratings to represent the benefits of swiftly developing safety technologies.

Increasing incidence of serious infectious diseases and inequalities in New Zealand: a national epidemiological study.

BACKGROUND: Although the burden of infectious diseases seems to be decreasing in developed countries, few national studies have measured the total incidence of these diseases. We aimed to develop and apply a robust systematic method for monitoring the epidemiology of serious infectious diseases. METHODS: We did a national epidemiological study with all hospital admissions for infectious and non-infectious diseases in New Zealand from 1989 to 2008, to investigate trends in incidence and distribution by ethnic group and socioeconomic status. We extended a recoding system based on the ninth revision of international classification of diseases (ICD-9) to the tenth revision (ICD-10), and applied this to data for hospital admissions from the New Zealand Ministry of Health, National Minimum Dataset. We filtered results to account for changes in health-care practices over time. Acute overnight admissions were the events of interest. FINDINGS: Infectious diseases made the largest contribution to hospital admissions of any cause. Their contribution increased from 20·5% of acute admissions in 1989-93, to 26·6% in 2004-08. We noted clear ethnic and social inequalities in infectious disease risk. In 2004-08, the age-standardised rate ratio was 2·15 (95% CI 2·14-2·16) for Maori (indigenous New Zealanders) and 2·35 (2·34-2·37) for Pacific peoples compared with the European and other group. The ratio was 2·81 (2·80-2·83) for the most socioeconomically deprived quintile compared with the least deprived quintile. These inequalities have increased substantially in the past 20 years, particularly for Maori and Pacific peoples in the most deprived quintile. INTERPRETATION: These findings support the need for stronger prevention efforts for infectious diseases, and reinforce the need to reduce ethnic and social inequalities and to address disparities in broad social determinants such as income levels, housing conditions, and access to health services. Our method could be adapted for infectious disease surveillance in other countries. FUNDING: New Zealand Ministry of Health, New Zealand Health Research Council.

Dietary Pattern Indicators among Healthy and Unhealthy Weight Adolescents Residing in Different Contexts across the Otago Region, New Zealand.

Reported obesity rates for adolescents in different urban and rural areas are inconsistent. We examined indicators of healthy and unhealthy dietary patterns among 1863 adolescents aged 13-18 years with a healthy or excess body weight attending 23 secondary schools in four different settlement types across the Otago region, New Zealand. An online survey included demographics and dietary behaviours. Height and weight were measured, and body mass index was calculated. New Zealand defined urban and rural settlement types were used. Home addresses determined a small area-level index of deprivation. Data were analysed using Chi-square tests and ANOVA. A logistic model was fitted to estimate adjusted odds ratios of excess weight. The proportion of adolescents with a healthy weight differed (p < 0.001) between the most (64.9%) and least (76.4%) deprived neighbourhood areas. There was only indicative evidence of differences between settlement types (p = 0.087). Sugar-sweetened beverage and fast-food consumption was more frequent in the most deprived areas (p < 0.001), and in urban versus rural settlements (p < 0.001). The most important associations with excess weight were area-level deprivation and ethnicity, but not settlement type. Prioritising socioeconomic factors irrespective of settlement type is necessary when developing interventions to improve dietary patterns and body weight status among adolescents.

A measure for quantifying the impact of housing quality on respiratory health: a cross-sectional study.

BACKGROUND: Damp and mould in homes have been established as risk factors for respiratory health. There is a need for a relatively straightforward assessment of the home that quantifies this risk. METHODS: Using data from 891 New Zealand houses, the utility of a Respiratory Hazard Index quantifying key attributes related to damp and mould was tested by studying its associations with self-reported respiratory symptoms. RESULTS: A dose-response relationship was found whereby each unit increase in the Respiratory Hazard Index was associated with an 11% increase in the odds of at least one episode of wheezing/whistling in the chest over the last 12 months (relative odds of 1.11 with a 95% CI 1.04%-1.20%). An 11% increase in the odds of an asthma attack over the last 12 months was estimated (relative odds of 1.11 with a 95% CI 1.01%-1.22%). These estimates were adjusted for household crowding levels, age, sex and smoking status. There was suggestive evidence of more steeply increasing odds of respiratory symptoms with increasing levels of the Respiratory Hazard Index for children aged under 7. In the worst performing houses according to the Index, a 33% reduction in the number of people experiencing respiratory symptoms (relative risk 0.67 with 95% CI 0.53 to 0.85) could be expected if people were housed in the best performing houses. CONCLUSIONS: This study showed that increased evidence of housing conditions supporting dampness and mould was associated with increased odds of respiratory symptoms. A valid housing assessment tool can provide a rational basis for investment in improved housing quality to improve respiratory health.

The Impact of Transport on Population Health and Health Equity for Maori in Aotearoa New Zealand: A Prospective Burden of Disease Study.

BACKGROUND: The land transport system influences health via a range of pathways. This study aimed to quantify the amount and distribution of health loss caused by the current land transport system in Aotearoa New Zealand (NZ) through the pathways of road injury, air pollution and physical inactivity. METHODS: We used an existing multi-state life table model to estimate the long-term health impacts (in health-adjusted life years (HALYs)) and changes in health system costs of removing road injury and transport related air pollution and increasing physical activity to recommended levels through active transport. Health equity implications were estimated using relative changes in HALYs and life expectancy for Maori and non-Maori. RESULTS: If the NZ resident population alive in 2011 was exposed to no further air pollution from transport, had no road traffic injuries and achieved at least the recommended weekly amount of physical activity through walking and cycling from 2011 onwards, 1.28 (95% UI: 1.11-1.5) million HALYs would be gained and $7.7 (95% UI: 10.2 to 5.6) billion (2011 NZ Dollars) would be saved from the health system over the lifetime of this cohort. Maori would likely gain more healthy years per capita than non-Maori, which would translate to small but important reductions (2-3%) in the present gaps in life expectancy. CONCLUSION: The current transport system in NZ, like many other car-dominated transport systems, has substantial negative impacts on health, at a similar level to the effects of tobacco and obesity. Transport contributes to health inequity, as Maori bear greater shares of the negative health impacts. Creating a healthier transport system would bring substantial benefits for health, society and the economy.

Injuries associated with housing conditions in Europe: a burden of disease study based on 2004 injury data.

BACKGROUND: The authors recently undertook a study for the World Health Organization estimating the European burden of injuries that can be attributed to remediable structural hazards in the home. Such estimates are essential for motivating injury prevention efforts as they quantify potential health gains, in terms of injuries prevented, via specific environmental interventions. METHODS: We combined exposure estimates from existing surveys and scenarios with estimates of the exposure-risk relationship obtained from a structured review of the literature on injury in the home and housing conditions. The resulting attributable fractions were applied to burden of injury data for the WHO European Region. RESULTS: This analysis estimated that two specific hazards, lack of window guards at second level and higher, and lack of domestic smoke detectors resulted in an estimated 7,500 deaths and 200,000 disability adjusted life years (DALYs) per year. In estimating the environmental burden of injury associated with housing, important deficiencies in injury surveillance data and related limitations in studies of injury risk attributable to the home environment were apparent. The ability to attribute proportions of the home injury burden to features of the home were correspondingly limited, leading to probable severe underestimates of the burden. CONCLUSIONS: The burden of injury from modifiable home injury exposures is substantial. Estimating this burden in a comprehensive and accurate manner requires improvements to the scope of injury surveillance data and the evidence base regarding the effectiveness of interventions.

Evaluation of the effectiveness of vehicle roll stability control (RSC) for high center of gravity light passenger vehicles in Australasia.

OBJECTIVE: Rollover crashes, which occur when the vehicle's side or roof makes impact with the ground, present particularly serious injury risk. Higher rollover risk has been found for high riding vehicles - those with a relatively high center of gravity compared to the width of the wheel track. Electronic Stability Control (ESC), which automatically applies brakes to individual wheels and reduces engine power to help drivers regain control when traction is lost, has been shown to be effective in preventing a proportion of rollovers. A newer safety technology, Roll Stability Control (RSC), uses similar technology aimed specifically to reduce rollover risk. This study sought to estimate rollover crash rates associated with the fitment of RSC compared to non-fitment for high center of gravity (CG) light passenger vehicles using an induced exposure analysis. METHODS: Police-recorded Australasian crash data were studied for the years 2008-2017. A quasi-induced exposure analysis was restricted to vehicles already equipped with ESC as vehicles fitted with RSC always have ESC fitted. Rollover risk associated with RSC fitment was assessed, controlling for year of crash, speed limit at crash location, year of vehicle manufacture, vehicle market group, driver age, driver gender and jurisdiction identifier. RESULTS: The analysis found a statistically significant rollover risk ratio of 0.76 (95% CI 0.62-0.93), representing a 24% reduction in rollover risk, associated with RSC fitment for vehicles manufactured between 2008 and 2017. Analysis by particular market groups found significant risk ratio reductions for commercial utilities and large SUVs, but not for the other high CG market groups individually. CONCLUSIONS: These results suggest that RSC is a highly effective safety feature for high CG vehicles. Fleet data from Australia and New Zealand showed declining rates of RSC fitment over recent years for SUVs, meaning the potential road safety benefits of the technology are not being fully realized.

Volunteering in older adulthood is associated with activity engagement and cognitive functioning.

Introduction: Given evidence that activity engagement in older adulthood can have protective effects on the aging brain, we investigated the idea that volunteering in the community, which often encompasses social, cognitive, and physical activity, might benefit cognition. Method: Ninety-one retired 65- to 75-year-olds reported their sociodemographic characteristics, wellbeing, volunteering, and activity engagement. They also completed computerized cognitive tests that tapped specific functions known to decline disproportionately with age. Results: Volunteering at least monthly was associated with better working memory and more social and cognitive activity. Mediation analyses indicated that volunteering was indirectly related to switching performance via cognitive activity. However, the volunteering-working memory association did not depend on activity engagement, leaving the underpinning mechanisms unclear. Conclusions: These findings provide new insight into positive associations between older people's volunteering, activity engagement, and cognitive functioning. However, further work is needed to understand the mechanisms that drive volunteering-cognition links, and to establish causality.

Home modifications to prevent home fall injuries in houses with Maori occupants (MHIPI): a randomised controlled trial.

BACKGROUND: As with many Indigenous populations internationally, Maori in New Zealand suffer health inequity. We aimed to assess the rate of fall injuries at home with and without home modifications in houses with Maori occupants. METHODS: We did a single-blind randomised controlled trial in the Wellington and Taranaki regions of New Zealand and enrolled owner-occupied households with at least one Maori occupant. Only households who stated they intended to live at that address for the subsequent 3 years were eligible for participation. We randomly assigned (1:1) households to either the intervention group, who received home modifications (handrails for outside steps and internal stairs, grab rails for bathrooms, outside lighting, repairs to window catches, high-visibility and slip-resistant edging for outside steps, fixing of lifted edges of carpets and mats, non-slip bath mats, and slip-resistant surfacing for outside areas such as decks) immediately, or the control group, who received the modifications 3 years later. Data on home injuries were obtained from the Accident Compensation Corporation and coded by study team members, who were masked to study group allocation. The primary outcome was the rate of medically treated fall injuries at home per household per year, analysed according to intention to treat. This Maori Home Injury Prevention Intervention (MHIPI) trial is now completed, and is registered with the Australian New Zealand Clinical Trials Registry, ACTRN12613000148774. FINDINGS: Between Sept 3, 2013, and Oct 1, 2014, 824 households were assessed for eligibility and 254 were enrolled, of which 126 (50%) were assigned to the intervention group and 128 (50%) were assigned to the control group. After adjustment for previous falls and geographical region, there was an estimated 31% reduction in the rate of fall injuries at home per year exposed to the intervention compared with households in the control group (adjusted relative rate 0·69 [95% CI 0·47-1·00]). INTERPRETATION: Low-cost home modifications and repairs can be an effective means to reduce injury disparities. The high prevalence of modifiable safety issues in Maori homes merits considerable policy and community effort. FUNDING: Health Research Council of New Zealand.

Why is the rate of annual road fatalities increasing? A unit record analysis of New Zealand data (2010-2017).

INTRODUCTION: Recent increases in road crashes have reversed New Zealand's formerly declining crash rates to produce annual fatal and serious injury counts that are 49% higher than the lowest rates achieved in 2013. METHOD: We model twenty-one factors in fatal and serious injury crashes, four years before and after 2013 using logistic regression. Three major factors are significantly different in the period after 2013, when crash rates increased: (1) alcohol as a cause, (2) learner licence holders, and (3) a regional effect for Auckland. Newly defined speed zones are a more common setting for crashes in the period of upturn but there is no coinciding elevated likelihood of 'speed as a causal factor'. Three factors related to road safety were less common: aged under 25-years old, fatigue, and not wearing a seatbelt. RESULTS: Results are compared to rates of prosecutions for alcohol-related driving offences over this period. It is possible that New Zealand's successful road safety initiatives of the past have been undermined by reduced levels of enforcement and an unexpected outcome from the graduated driving licence system.

Evaluating natural experiments to measure the co-benefits of urban policy interventions to reduce carbon emissions in New Zealand.

Finding effective policy interventions for addressing the Sustainable Development Goals, such as reducing carbon emissions (SDG 13), which can also enhance good health and wellbeing (SDG 3), is urgent. Many promising interactions occur between sustainable cities and communities (SDG 11), clean water and sanitation (SDG 6) and affordable and clean energy (SDG 7), which sit at the centre of integrated urban planning and regeneration. In this paper, we consider the framing and findings of four policies we have evaluated as natural experiments, all of which have important co-benefits, which were not always the focus of the initial policies. These policies are: the installation of cycleways and walkways in existing suburbs; a central government measure to recentralise employment after the 2011 Christchurch earthquakes; the streamlining of housing developments by reducing land-use regulation; and ongoing changes of policy about public housing investment. We show that having a clear understanding of the benefits of increased physical activity for health, for example, could accelerate the reduction of carbon emissions. Also, decisions about infrastructure, housing and job locations can generate health and environmental gains if supported by broader public transport investments. Cycling and walking are also more likely to substitute for short habitual car trips. Similarly, measuring the co-benefits of differential residential models, relating to land-use and renewable energy, provides a framework that can facilitate learning from policy interventions, enabling wider and potentially more rapid generalisation of policies, including those for climate change mitigation.

Study Protocol of a Randomized Controlled Trial of Home Modification to Prevent Home Fall Injuries in Houses with Maori Occupants.

Worldwide, injuries due to falls in the home impose a substantial burden and merit considerable effort to find effective prevention measures. The current study is one of very few randomized controlled trials that assess the effectiveness of home modification for preventing falls. It is the first carried out with a minority or indigenous community and focused on reducing inequities. Just over 250 households in Aotearoa, New Zealand, with Maori occupants were recruited in two strata, 150 from the Wellington region and 100 from the Taranaki region. These were randomly allocated to equally sized treatment and control groups within the respective regions, the treatment group receiving a package of home modifications designed to prevent falls at the start of the study, and the control group receiving the package at the end of the study. Injury data came from the Accident Compensation Corporation, a state-owned no-fault injury insurer. This provided coverage of virtually all unintentional injuries requiring medical treatment. Matched injury claims were made available for analysis once all identifying fields had been removed. These data will be pooled with data for Maori households from the already-conducted Home Injury Prevention Intervention (HIPI) study, which tested an identical intervention on the general population. In the analysis, the primary outcome measure will be fall injury rates over time, comparing treatment and control households, adjusting for the stratum and prior falls in the household. A secondary measure will be the rates of specific injuries, which are most likely to be prevented by the package of modifications tested. We anticipate that the findings will provide robust evidence for effective injury prevention measures that can reduce an important contributor to health inequities for indigenous populations such as the Maori.

Built environment changes and active transport to school among adolescents: BEATS Natural Experiment Study protocol.

INTRODUCTION: Natural experiments are considered a priority for examining causal associations between the built environment (BE) and physical activity (PA) because the randomised controlled trial design is rarely feasible. Few natural experiments have examined the effects of walking and cycling infrastructure on PA and active transport in adults, and none have examined the effects of such changes on PA and active transport to school among adolescents. We conducted the Built Environment and Active Transport to School (BEATS) Study in Dunedin city, New Zealand, in 2014-2017. Since 2014, on-road and off-road cycling infrastructure construction has occurred in some Dunedin neighbourhoods, including the neighbourhoods of 6 out of 12 secondary schools. Pedestrian-related infrastructure changes began in 2018. As an extension of the BEATS Study, the BEATS Natural Experiment (BEATS-NE) (2019-2022) will examine the effects of BE changes on adolescents' active transport to school in Dunedin, New Zealand. METHODS AND ANALYSIS: The BEATS-NE Study will employ contemporary ecological models for active transport that account for individual, social, environmental and policy factors. The published BEATS Study methodology (surveys, accelerometers, mapping, Geographic Information Science analysis and focus groups) and novel methods (environmental scan of school neighbourhoods and participatory mapping) will be used. A core component continues to be the community-based participatory approach with the sustained involvement of key stakeholders to generate locally relevant data, and facilitate knowledge translation into evidence-based policy and planning. ETHICS AND DISSEMINATION: The BEATS-NE Study has been approved by the University of Otago Ethics Committee (reference: 17/188). The results will be disseminated through scientific publications and symposia, and reports and presentations to stakeholders. TRIAL REGISTRATION NUMBER: ACTRN12619001335189.