Geospatial Research Institute: Theses and Dissertations
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Item Restricted The built environment and health: a spatial analysis of type 2 diabetes and childhood weight status in urban New Zealand.(University of Canterbury, 2019) Wiki, Jesse DiamondThe built environment is an integral aspect of everyday life. It provides the context in which individual behaviours are set and can affect both individual and population health. It is shaped by distal systematic drivers which influence demographic and epidemiological changes such as the globalisation of economic processes, urbanisation, mechanisation, changing agricultural and trade policies, and dietary transitions. These systematic drivers, in turn, influence local environments which act as proximal determinants of population outcomes. Subsequently, the contextual impact of the local built environment is considered to be an influential aspect of spatial disparities in population health outcomes. The focus of this thesis is on health outcomes of high weight status in children and population level Type 2 Diabetes Mellitus (T2DM). The prevalence of these health issues has increased alongside societal, demographic and cultural changes. While there are various biological, behavioural and environmental risk factors which influence the development of these health issues there is still much to be learned about both direct and indirect causes. The overall aim of this thesis is to analyse the built environment in urban New Zealand and investigate associations with the spatial epidemiology of two health outcomes, high weight status in children and population level T2DM. Despite substantial research and significant public attention directed toward these health issues within Aotearoa New Zealand, there are still critical gaps in the spatial understanding of such health outcomes. Current literature also highlights a lack of research which focuses on T2DM. This thesis addresses such research gaps using an ecological approach to analysis which utilises Geographic Information Systems (GIS) and spatial epidemiological methods. This is the first study in New Zealand to spatially quantify the effects of multiple environmental exposures on health outcomes of both high weight status in children and population level T2DM, for all urban areas, using a geospatial approach. It establishes novel measures of the built environment using data on fast food outlets, takeaways, dairy/convenience stores, supermarkets, fruit and vegetable stores, physical activity facilities, and greenspace to assess potential associations between contextual factors and health outcomes. In the context of this study, the former three of these categories are considered unhealthy exposures and detrimental to overall health. The latter four categories, in contrast, are considered to be healthy exposures and health-promoting. This thesis has, in turn, made original contributions to the current body of knowledge by: (1) including the use of both established and novel approaches to measuring various aspects of the built environment, and (2) analysing spatial data on health outcomes of high weight status in children and population level T2DM for all urban areas of New Zealand and assessing potential associations with the built environment. Such analysis also provides the opportunity to assess how the built environment may relate to not only outcomes of multiple chronic health conditions, but also different population groups. When considering relationships between measures of the built environment and socioeconomic deprivation, results of this study indicate that accessibility to both and unhealthy and healthy exposures is generally higher in the most deprived areas compared to the least deprived areas. This study also found some notable results when looking at the spatial distribution of both high weight status in children and population level T2DM, finding that T2DM is more spatially clustered than high weight status in children. Both health outcomes were also shown to be heavily influenced by demographic factors and associated with accessibility to environmental exposures. Interestingly, results show that both of these health issues may be more heavily influenced by health-promoting resources than those considered detrimental to health. Health-promoting resources were shown to have a consistently positive effect on both health outcomes, while those considered detrimental to health showed varying, and largely insignificant, associations. Caution must be exercised, however, to ensure that a balanced approach is taken within prevention efforts which addresses environmental factors as well as economic accessibility, individual behaviours and societal norms. The current study has implications for both policy and future research efforts as a deeper knowledge of local environments forms a basis on which to better understand spatial associations between the built environment and health as well as formulate policy directed toward environmental influences on chronic health conditions. It is vital to consider such contextual influences in order to better understand the spatial epidemiology of chronic health conditions in Aotearoa New Zealand. Accounting for these contextual influences within both research and policy can not only enhance understandings of such health concerns, but can also identify opportunities for prevention efforts. This thesis has, in turn, provided insight into such associations and a base from which to further address the complexities of such issues using a geospatial approach.Item Open Access Exploring the social and spatial context of adult obesity in Aotearoa New Zealand : a spatial microsimulation approach.(University of Canterbury, 2017) Watkins, Alison F.Obesity rates have risen substantially in recent decades. A large body of research links excess body fat to a variety of health conditions including cardio vascular disease (CVD), certain cancers, and non-insulin-dependent diabetes mellitus (NIDDM). Research also indicates that recent social and economic change are among the underlying causes of the ‘obesity epidemic.’ Aotearoa New Zealand exhibits one of the highest obesity rates in the Organisation for Economic Co-operation and Development (OECD). Reducing obesity in New Zealand is therefore a priority for policy makers. Existing research demonstrates that the burden of obesity is not evenly distributed in Aotearoa New Zealand. Obesity rates are highest among Māori and Pacific Peoples, and those living in the most socially deprived areas, neither of which are evenly distributed spatially. Sampling constraints mean that standard statistical methods are unable to estimate obesity rates at a spatial scale smaller than at the District Health Board (DHB) level. Yet fine-scale estimates of obesity would help to understand the distribution of obesity at neighbourhood level and thus provide policy makers with a tangible tool to target and combat obesity. Neighbourhoods in Aotearoa New Zealand vary across the regions of the country so to rely on large scale statistics for decision-making risks overlooking small pockets that would benefit from targeted assistance. The aim of this thesis is to put population level adult obesity in New Zealand into a spatial context using spatial microsimulation modelling (SMSM). SMSM is a technique that combines detailed microdata from the New Zealand Health Survey (NZHS) with small area census data to generate obesity estimates at a neighbourhood level. There are three key findings in this thesis. First, obesity is clustered into a spatially confined subset of areas, primarily associated with high deprivation mediated by age and ethnicity. Second, a broad range of obesity rates were estimated for small areas, varying from 15.3% to 67.2%; these estimates of obesity in 2013 are novel and not available through other sources. Third, projections from the model for 2018 and 2023 predict only small changes in obesity rates, yet a widening of obesity related health inequities. The SMSM outputs will be useful for operational policy decisions as well as informing policy more broadly. Collectively, the work presented here extends the understanding of the geography of obesity in Aotearoa New Zealand.Item Open Access A geospatial approach to measuring the built environment for active transport, physical activity and health outcomes.(University of Canterbury, 2016) Donnellan, Niamh MarieActive transport and physical activity behaviours are recognised as important determinants of a number of health outcomes, including obesity. Over the last decade, there has been a significant amount of research focused on the need to quantify the ‘walkability’ of neighbourhoods or urban environments as a means of predicting physical activity behaviours. The most common methods used to create indices of walkability focus on a combination of land use mix, street connectivity and dwelling density, as developed by Frank et al., (2005). What is largely missing in this research, however, is a focus on other modes of active transport (such as cycling) and a related recognition of how different delineations (Euclidean and network) of neighbourhoods may affect results. This thesis investigates the influence of the built environment at a number of spatial levels and different neighbourhood delineations, using both standard and novel methods. This research advances and improves our current understandings of the built environment by being the first to use a novel method based on kernel density estimation, to measure associations between the built environment, active transport, physical activity, and health outcomes in a city in New Zealand (Wellington City). This novel method is used to create an Enhanced Walk Index, improving on standard walk indices by including measures of slope, street lights and footpaths and tracks. In addition, this research is the first to test and validate indices of bikeability and neighbourhood destination accessibility (NDAI), based on the novel method. Results of the study suggest that the novel Basic and Enhanced Walk Indices had strong significant positive associations with active transport and overweight/obesity. In comparison the standard method had weaker significant associations, potentially indicating previous research has underestimated the effect of the built environment on active behaviours and health outcomes. In addition, the novel indices of bikeability and NDAI also showed significant positive associations with active transport and overweight/obesity, however effect sizes were small. Furthermore, results varied depending on the type of neighbourhood delineation and spatial scale used. However, in general, the network buffer showed stronger associations between indices of the built environment and active transport, physical activity and overweight/obesity. This research thus strengthens current international and national evidence on how the built environment affects active transport, physical activity behaviours and health outcomes. It expands a preoccupation with walkability to encompass other modes of transport, such as bikeability. Furthermore it provides an alternative, and potentially more nuanced novel method to assess the relationships between the built environment, active transport, physical activity and health outcomes.Item Open Access An exploration of the effects of roads and traffic on mental health in Auckland, New Zealand.(University of Canterbury, 2016) Curry, KirstenMental illness is the third highest cause of poor health in New Zealand, accounting for 11% of the total burden of disease. Like many other chronic illnesses, associations between mental health outcomes and the built and social environment have been found. Roads and traffic have been associated with reduced mental wellbeing as they are a source of stress for individuals and are disruptive to daily activities; partially a result of the air and noise pollution produced. The primary aim of this research was to investigate the relationship between exposure to traffic and mental health treatment in Auckland, New Zealand. Measures of distance to motorways, road class metrics, traffic volume and traffic density were produced for all households in Auckland. Poor mental health for individuals was measured by cases of issued prescriptions for mood and anxiety disorders or use of addiction related services in a 12-month period, sourced from the Ministry of Health Programme for the Integration of Mental Health Data (PRIMHD). A random sample of Auckland address points were selected for comparison. Logistic regression was used to investigate possible associations. The social composition of neighbourhoods were considered as confounders, including income, deprivation and social capital indicators. The effect of green space was also investigated. No detectable effect of traffic volume or traffic density on mental health was found. However, the volume of heavy commercial vehicles was associated with poor mental health, with a 3% increase in treatment for every 1000 vehicles on motorways within 100 metres of home address points. The neighbourhood has an important influence on mental health outcomes; deprivation and indicators of social capital are among the strongest predictors, but they also predicted exposure to traffic. Controlling for these confounders, the effect of heavy commercial vehicles on motorways decreased to 1% increase in treatment per 1ooo vehicles. This research provides a useful contribution to the literature investigating traffic and mental health due to the geographic scale at which it is performed, and the use of individual exposure and health measures.Item Open Access Geographic variation in exposure to the 2010/11 Canterbury earthquake series and its implications on adverse mental health outcomes.(University of Canterbury, 2016) Hogg, Daniel AndreasNatural hazard disasters often have large area-wide impacts, which can cause adverse stress-related mental health outcomes in exposed populations. As a result, increased treatment-seeking may be observed, which puts a strain on the limited public health care resources particularly in the aftermath of a disaster. It is therefore important for public health care planners to know whom to target, but also where and when to initiate intervention programs that promote emotional wellbeing and prevent the development of mental disorders after catastrophic events. A large body of literature assesses factors that predict and mitigate disaster-related mental disorders at various time periods, but the spatial component has rarely been investigated in disaster mental health research. This thesis uses spatial and spatio-temporal analysis techniques to examine when and where higher and lower than expected mood and anxiety symptom treatments occurred in the severely affected Christchurch urban area (New Zealand) after the 2010/11 Canterbury earthquakes. High-risk groups are identified and a possible relationship between exposure to the earthquakes and their physical impacts and mood and anxiety symptom treatments is assessed. The main research aim is to test the hypothesis that more severely affected Christchurch residents were more likely to show mood and anxiety symptoms when seeking treatment than less affected ones, in essence, testing for a dose-response relationship. The data consisted of mood and anxiety symptom treatment information from the New Zealand Ministry of Health’s administrative databases and demographic information from the National Health Index (NHI) register, when combined built a unique and rich source for identifying publically funded stress-related treatments for mood and anxiety symptoms in almost the whole population of the study area. The Christchurch urban area within the Christchurch City Council (CCC) boundary was the area of interest in which spatial variations in these treatments were assessed. Spatial and spatio-temporal analyses were done by applying retrospective space-time and spatial variation in temporal trends analysis using SaTScan™ software, and Bayesian hierarchical modelling techniques for disease mapping using WinBUGS software. The thesis identified an overall earthquake-exposure effect on mood and anxiety symptom treatments among Christchurch residents in the context of the earthquakes as they experienced stronger increases in the risk of being treated especially shortly after the catastrophic 2011 Christchurch earthquake compared to the rest of New Zealand. High-risk groups included females, elderly, children and those with a pre-existing mental illness with elderly and children especially at-risk in the context of the earthquakes. Looking at the spatio-temporal distribution of mood and anxiety symptom treatments in the Christchurch urban area, a high rates cluster ranging from the severely affected central city to the southeast was found post-disaster. Analysing residential exposure to various earthquake impacts found that living in closer proximity to more affected areas was identified as a risk factor for mood and anxiety symptom treatments, which largely confirms a dose-response relationship between level of affectedness and mood and anxiety symptom treatments. However, little changes in the spatial distribution of mood and anxiety symptom treatments occurred in the Christchurch urban area over time indicating that these results may have been biased by pre-existing spatial disparities. Additionally, the post-disaster mobility activity from severely affected eastern to the generally less affected western and northern parts of the city seemed to have played an important role as the strongest increases in treatment rates occurred in less affected northern areas of the city, whereas the severely affected eastern areas tended to show the lowest increases. An investigation into the different effects of mobility confirmed that within-city movers and temporary relocatees were generally more likely to receive care or treatment for mood or anxiety symptoms, but moving within the city was identified as a protective factor over time. In contrast, moving out of the city from minor, moderately or severely damaged plain areas of the city, which are generally less affluent than Port Hills areas, was identified as a risk factor in the second year post-disaster. Moreover, residents from less damaged plain areas of the city showed a decrease in the likelihood of receiving care or treatment for mood or anxiety symptoms compared to those from undamaged plain areas over time, which also contradicts a possible dose-response relationship. Finally, the effects of the social and physical environment, as well as community resilience on mood and anxiety symptom treatments among long-term stayers from Christchurch communities indicate an exacerbation of pre-existing mood and anxiety symptom treatment disparities in the city, whereas exposure to ‘felt’ earthquake intensities did not show a statistically significant effect. The findings of this thesis highlight the complex relationship between different levels of exposure to a severe natural disaster and adverse mental health outcomes in a severely affected region. It is one of the few studies that have access to area-wide health and impact information, are able to do a pre-disaster / post-disaster comparison and track their sample population to apply spatial and spatio-temporal analysis techniques for exposure assessment. Thus, this thesis enhances knowledge about the spatio-temporal distribution of adverse mental health outcomes in the context of a severe natural disaster and informs public health care planners, not only about high-risk groups, but also where and when to target health interventions. The results indicate that such programs should broadly target residents living in more affected areas as they are likely to face daily hardship by living in a disrupted environment and may have already been the most vulnerable ones before the disaster. Special attention should be focussed on women, elderly, children and people with pre-existing mental illnesses as they are most likely to receive care or treatment for stress-related mental health symptoms. Moreover, permanent relocatees from affected areas and temporarily relocatees shortly after the disaster may need special attention as they face additional stressors due to the relocation that may lead to the development of adverse mental health outcomes needing treatment.Item Open Access Assessing the influence of environment and socio-economics on spatial and temporal patterns of COPD hospitalisation in Christchurch : a GIS approach.(University of Canterbury, 2016) Poynter, Robert ArthurThis thesis examines links between environmental conditions and the socio-economic and demographic determinants of Chronic Obstructive Pulmonary Disease (COPD) in Christchurch, New Zealand. COPD is a progressive condition characterised by reduction in lung function and limited mobility. Tobacco smoking and exposure to air pollution are considered the main causal factors. COPD is the fifth leading cause of mortality globally, and is projected to become the third by 2030. Geographic Information Systems serves a vital role in furthering understanding of the spatial patterns of the condition, and the prevalence of associated variables across space. The aim of this thesis is to engage GIS tools to assess the spatial and temporal patterns of COPD hospitalisation events in relation to air pollution distribution, based on land-use regression modelling, and associated socio-economic variables. To test for the effects of these socio-economic variables, census data was included relating to deprivation levels, and percentages of Maori/Pacific Islanders, smokers and elderly of the population at meshblock and area unit levels. Temporal analysis sought to find correlation between monitored particulate matter, hospitalisation rates and the temperature and wind speed patterns that may affect this. Geographic Weighted Regression (GWR) models found that higher hospitalisation rates were spatially correlated with meshblocks containing high predicted air pollution and deprivation. Maori/Pacific Islander and smoking percentages were moderately associated with hospitalisation event distribution. Temporally, it was found that hospitalisation events occur most predominately in periods of high pollution, lower temperatures and still wind conditions. This thesis is the first research to include spatial and temporal techniques to explore COPD hospitalisation patterns in Australasia.Item Open Access Measuring the exposure to obesogenic environments among New Zealand school children.(University of Canterbury. Geography, 2015) Wilson, AndreasThe prevalence of obesity has increased greatly in the last 30 years. Intensified urban landscapes have created environments that facilitate rising obesity rates. The level of unhealthy food consumption and physical activity accessibility has become imbalanced within the built and social environments of individuals. The term obesogenic environment has been used to describe the increased exposure to obesity, based on the characteristics of the surrounding environment. Previous academic literature has attempted to measure the contribution of obesogenic environment exposure to obesity health outcomes. The key aim of this research is to measure the correlation between obesogenic environments and BMI outcomes of New Zealand school children aged 5-14. Part 1 of this research method considered all children aged 5-14 sampled in the New Zealand Health Survey (NZHS) 2013/2014. Linear regression analysis was used to determine the correlation between BMI and selected NZHS participant responses; the key analysis in part 1 was the correlation between BMI and participants mode of transport to and from school. Part 2 of this research method focused on the New Zealand city of Hamilton. The research method used NZHS data to measure participant exposure to obesogenic environments based on the health responses given by participants. Geospatial network analysis was used to determine the NZHS participant’s home, route and school environments. Obesogenic environment exposure was defined by the Hamilton food and physical environment attributes contained within euclidean buffer zones created around the participant’s home, route and school environment. Linear regression analysis was then used to determine the geospatial correlation between the participant’s environment exposure and BMI outcomes. The results of this research method suggest that participant’s exposure to obesogenic environments did not contribute to obesity health outcomes, based on the lack of statistical evidence provided by the linear regression analysis.Item Open Access Spatial patterns in excess winter morbidity among the elderly in New Zealand(University of Canterbury. Geography, 2015) Brunsdon, Nicholas DavidIt has been established in New Zealand and internationally that morbidity and mortality tends to rise during colder winter months, with a typical 10-20% excess compared to the rest of the year. This study sought to investigate the spatial, temporal, climatic and demographic patterns and interactions of excess winter morbidity (EWMb) among the elderly in New Zealand. This was achieved through analysis of acute hospital admissions in New Zealand between 1996 and 2013 for all patients over the age of 60 with an element of circulatory or respiratory disease (N=1,704,317) including a primary diagnosis of circulatory (N=166,938) or respiratory (N=62,495) disease. A quantitative approach included ordinary least squares and negative binomial regression, graphical analysis and age standardisation processes. Admission rates and durations were regressed against a set of 16 cold spell indicators at a national and regional scale, finding significant spatial variation in the magnitude of EWMb. EWMb was ubiquitous across New Zealand despite climatic variation between regions, with an average winter excess of 15%, and an excess of 51% for chronic obstructive pulmonary disease (COPD). Statistically significant relationships were found between hospital admission durations and cold spells up to 28 days prior; however the magnitude would not be expected to have a significant impact on hospital resources. Nonetheless, there is potential for preventative public health strategies to mitigate less severe morbidity associated with cold spells. Patients over the age of 80 were particularly vulnerable to EWMb; however socioeconomic deprivation and ethnicity did not affect vulnerability. Patients residing in areas of high socioeconomic deprivation or identifying with Maori or Pacific Island ethnicity experienced significantly shorter admissions than other groups, and this warrants further investigation. Further investigation into winter COPD exacerbations and non-climatic factors associated with the EWMb are recommended. A comprehensive understanding of EWMb will enable preventative measures that can improve quality of life, particularly for the elderly population.Item Open Access Using a natural experiment to assess the effect of spatial barriers on health service utilization.(University of Canterbury. Geography, 2014) MacRae, JaydenThe closure of the Manawatu Gorge in August 2011 caused a change in the travel time for patients living in the eastern area of the MidCentral Health District to their main hospital and health services located in Palmerston North. This presented an opportunity to study the effect a change in travel time and spatial access had on a population before and after such an event. This study used a retrospective cohort design, using routinely collected data from general practice, emergency department, hospital admissions and outpatient services. The investigation was completed using novel geospatial information systems methods to produce high fidelity data for analysis with free and open source software by developing and validating two new methods of improving geocoding data quality and a new travel time prediction model. Potential and realised spatial accessibility measures were calculated for 101,456 patients over 3.5 years while the gorge was both open and closed. Catchment sensitivity analysis and two-step floating catchment area using distance decays presented complimentary evidence of accessibility change during the Manawatu Gorge closure. Analysis of utilisation measures in both primary and secondary care were correlated with travel time. Utilisation of general practice services appeared to be negatively impacted by increased travel time when comparing realised accessibility in a control and intervention group during the gorge closure. It appeared as though other factors affected access to health services to a greater degree than an increase of up to fifteen minutes travel time.Item Open Access An exploration of the associations between urban natural environments and indicators of mental and physical health.(University of Canterbury. Geography, 2014) Nutsford, DanielNatural environments, namely green and blue spaces, have been found to have positive influences on mental health outcomes globally. As the contribution of poor mental health to the disease burden increases, the mechanisms through which natural environments may improve health are of growing importance. This study creates a novel visibility index methodology and investigates whether i) views of natural environments and ii) access to natural environments, are associated with psychological stress and physical activity in Wellington, New Zealand. It also builds upon the work conducted in New Zealand as the first study to investigate links between blue space and mental health and provides an insight into the mechanisms through which increased natural environments may improve health. Individual level data for 442 individuals from the New Zealand Health Survey was obtained and Geographical Information Systems (GIS) were used to investigate whether area-level exposure to natural environments influenced their psychological stress and levels of physical activity. Results from regression analysis indicate that increased distant visible green space (beyond 3km), visible blue space, and a combination of green and blue spaces from neighbourhood centroids reduce psychological stress. Some access measures to natural environments were found to have positive associations with psychological stress, however increased proximal access to green space was associated with decreased physical activity. The findings conclude that the visibility of natural environments appears to have stronger associations with stress reduction than access to them. The findings of this paper should influence urban development and inform decision and policy making, particularly the development and/or relocation of health related facilities.Item Open Access Neighbourhood level impact of crime on community health outcomes(University of Canterbury. Geography, 2012) Willoughby, Matthew JamesObjectives: Previous research has demonstrated an association between crime, the fear of crime and negative mental and physical health outcomes. The aim of this thesis is to investigate whether there is statistically significant association between recorded crime and stress-related health outcomes at a census area unit (CAU) level in Christchurch, New Zealand. Methods: Using multivariate linear regression and crime and health data from 2008-2010 (Calendar Years) this relationship was analysed. Results: Violent crime (assault) in a neighbourhood was significantly associated with poorer physical and mental health outcomes. Coefficient values indicate a strong statistical association between higher violent crime and higher heart attack [0.513 (0.161)**] and anxiety [0.474 (0.145)**] rates at a 95% confidence interval [CI]. Two confounding variables were found to have a positive association with positive health outcomes. ‘Median Income’ *-0.359 (0.166)**+ was associated with reduced heart attack admissions and ‘Community Resources’ [ -0.213 (0.078)**] was associated with reduced anxiety admissions. Conclusions: Crime reduction and community support initiatives should be encouraged. The results from this study demonstrate that there is a statistically significant association between crime and health at a neighbourhood level (CAU) and is reflective of findings from previous literature and add credence to crime as an environmental stressor.Item Open Access The Spatial and Temporal Patterns of Anxiety and Chest Pain Resulting From The Canterbury Earthquakes(University of Canterbury. Geography, 2013) Reed, Kimberley JaneThe aim of this thesis was to examine the spatial and the temporal patterns of anxiety and chest pain resulting from the Canterbury, New Zealand earthquaeks. Three research objectives were identified: examine any spatial or termporal clusters of anxiety and chest pain; examine the associations between anxiety, chest pain and damage to neighbourhood; and determine any statistically significant difference in counts of anxiety and chest pain after each earthquake or aftershock which resulted in severe damage. Measures of the extent of liquefaction the location of CERA red-zones were used as proxy measures for earthquake damage. Cases of those who presented to Christchurch Public Hospital Emergency Department with either anxiety or chest pain between May 2010 and April 2012 were aggregated to census area unit (CAU) level for analysis. This thesis has taken a unique approach to examining the spatial and spatio-temporal variations of anxiety and chest pain after an earthquake and offers unique results. This is the first study of its kind to use a GIS approach when examining Canterbury specific earthquake damage and health variables at a CAU level after the earthquakes. Through the use of spatio-termporal scan modelling, negative and linear regression modelling and temporal linear modelling with dummy variables this research was able to conclude there are significant spatial and temporal variations in anxiety and chest pain resulting from the earthquakes. The spatio-termporal scan modelling identified a hot cluster of both anxiety and chest pain within Christchurch at the same time the earthquakes occurred. The negative binomial model found liquefaction to be a stronger predictor of anxiety than the Canterbury Earthquake Recovery Authority's (CERA) land zones. The linear regression model foun chest pain to be positively associated with all measures of earthquake damage with the exception of being in the red-zone. The temporal modelling identified a significant increase in anxiety cases one month after a major earthquake, and chest pain cases spiked two weeks after an earthquake and gradually decreased over the following five weeks. This research was limited by lack of control period data, limited measures of earthquake damage, ethical restrictions, and the need for population tracking data. The findings of this research will be useful in the planning and allocation of mental wellbeing resources should another similar event like the Canterbury Earthquakes occur in New Zealand.Item Open Access Socioeconomic inequalities in adolescent smoking behaviour and neighbourhood access to tobacco products.(University of Canterbury. Geography, 2011) Bowie, Christopher JohnYouth smoking is an important aspect of tobacco research as most adult smokers first experiment with and initiate tobacco use during their adolescence. Policy makers and researchers have given youth smoking issues a significant amount of attention over the last 20 years and this has led to significant reductions in youth smoking prevalence in New Zealand. More recently the decline in youth smoking prevalence has reached a plateau. Evidence now shows that while overall smoking prevalence has reduced, inequalities between ethnic and social groups has actually increased. This is an international trend. Young people living in low socioeconomic status areas and belonging to minority ethnic groups are at much higher risk of being a current smoker than their less deprived peers. A number of overseas studies have investigated the spatial relationship between aspects of the neighbourhood environment and adolescent smoking behaviour in an attempt to identify the most at risk groups. In particular the effect of neighbourhood socioeconomic status and the degree of access to tobacco outlets is believed to influence adolescent smoking behaviour. In New Zealand analysis of this type has mainly focused on adult smoking behaviour and the effect of tobacco outlet access is as yet unstudied. This study examines the effect of neighbourhood and high school socioeconomic status on adolescent smoking behaviour, attitudes and beliefs in Christchurch. Using information from the 2006 New Zealand Census, spatial variations in reported neighbourhood smoking prevalence have been examined. In addition, analysis of responses to smoking questions in the 2008 Year 10 In-depth Survey have been carried out show how school socioeconomic status can influence underlying attitudes and beliefs young people hold towards smoking and tobacco products. Spatial analysis has also been performed on the census dataset to investigate the relationship between neighbourhood access to tobacco outlets and youth smoking behaviour after controlling for neighbourhood deprivation. To supplement each of these quantitative data sources, focus group interviews were carried out at two high schools (one low and one high socioeconomic status). Findings from these interviews are presented as further insight into adolescent attitudes and beliefs towards smoking. Results of this research show that there is a socioeconomic effect at both a neighbourhood and school level on all adolescent smoking behaviours, attitudes and beliefs examined, except for smoking cessation. There is also evidence of greater access to tobacco outlets in low socioeconomic neighbourhoods but not so around high schools. Increased access to tobacco outlets is linked to increased adolescent smoking prevalence, more so among females than males, but this relationship disappeared in age groups 20 and above.Item Open Access Public Health Service Rationing for Elective Surgery in New Zealand: 2004-2007(University of Canterbury. Geography, 2011) Valentine, Samuel MillwardThe New Zealand health system is two-tiered with elective treatments are performed by both publicly funded state hospitals and by private hospitals. Publicly funded operations are rationed using a prioritisation system which was introduced in 1998 to curtail expanding waiting lists for elective surgery. One of the aims of the new booking system was to generate national tools for prioritising patients in order to improve the equality of access to public elective surgery throughout New Zealand. However, priority scoring systems were not implemented in a consistent manner and access to elective surgery remains very unequal. Despite large media attention and a high public profile, waiting times have attracted little research in medical geography or within the wider social sciences community. The subject has been partly reserved for public health commentators within the medical field, who have found that variation in waiting times has much to do with the referral practices of physicians, the management of waiting lists by District Health Board (DHB) staff and the amount of private practice that occurs within each district. Most notably several studies have identified that in areas associated with high private admissions, patients tend to suffer higher waiting times for the same procedures in the public hospital system. This study examines the performance of the New Zealand Booking System (NZBS) during the years 2004 to 2007 to assess the equitable delivery of publicly funded elective surgery procedures. Waiting times (NBRS) and admissions (NMDS) datasets were sourced from the New Zealand Health and Information Service (NZHIS) of The Ministry of Health. Mean and Median waiting times were compared spatially between each of New Zealand’s 21 DHBs, compared with Australian waiting times and then broken down into five common medical specialties. Waiting times were then analysed by ethnicity, level of material deprivation and other individual factors using data from the 2006 New Zealand Census. Finally, rates of admissions were calculated for the public and private hospital sectors during the study period. These were used to correlate waiting times results with the amount of private practice in each DHB. ACC cases were extracted from the dataset to avoid bias in waiting times as much of this work is contracted out to the private sector and not subject to lengthy waiting times for treatment. A number of medical specialists and hospital administrators were interviewed to discuss results, explain prioritisation tools and management practices. Results showed large variations in the median waiting times of New Zealand DHBs. A north south gradient is observed in which southern DHBs suffer longer waits for care. Vastly better results were observed for Australian public hospitals than those seen in New Zealand. For waiting times as determined by individual factors, Maori and Pacific Island patients and those from lower socio-economic backgrounds suffered longer waiting times nationwide although, in certain DHBs inequalities for access to elective surgery were exacerbated. However, ethnic differences were more pronounced than socio-economic variations. Admissions results showed significant positive correlations between the amount of private practice and the waiting times experienced in each DHB which are supported by previous research. Feedback from interviews confirmed inconsistency in the use of scoring tools, manipulation occurring on behalf of the DHB management to achieve performance goals set by the Ministry of Health and provided some further explanation of the other quantitative results. Access to elective surgery is determined partly by location of residence, ethnicity, deprivation and where hospital resources are located but most importantly by the willingness to pay for treatment within the private hospital sector and the ability to manipulate the public prioritisation system.Item Open Access Examining place influence on alcohol related behaviour and health outcomes in New Zealand.(University of Canterbury. Geography, 2010) Owuor, Carey Francis AyukaMuch of the literature on the determinants of health, including alcohol consumption, has focussed on differences in individual socio-economic status as a primary risk factor. However, it has been shown that variation in health between places can be attributed to both the characteristics of the people who live in those places (composition) and also to the characteristics of the places where people live (context). From the 1990s, there has been considerable interest in the role of neighbourhoods, specifically whether their social and physical characteristics are important in explaining inequalities in health. The main aim of this thesis is to determine the influence of ‘place’ effects on alcohol-related behaviour and health and social outcomes in New Zealand. To achieve this, data was obtained for hospitalisation and mortality directly related to alcohol consumption. Age standardised rates of alcohol related hospitalisation and mortality were calculated for different census areas units over time. Secondly, a database of all alcohol outlets including type and category was obtained from the Liquor Licensing Authority and geocoded for all meshblocks in New Zealand. Using ArcGIS road network functionality, least cost distance to nearest alcohol outlets was calculated. In addition, two buffers (800 and 3000 metres) were created around the population weighted centroids of each meshblock. Statistical analysis was undertaken to examine the distribution of alcohol outlets in areas of differing socio-economic status. Thirdly, binary logistic regression was used to examine the relationship between various access measures developed and individual alcohol related behaviour from the New Zealand Health Survey (2006/07). Lastly, Ordinary Least Squares regression was used to establish the association between the density of alcohol outlets and crime, and alcohol related hospitalisation. The results reveal there is increasing geographic inequality of both hospitalisation and mortality between the most and the least deprived areas in New Zealand. Secondly, the results consistently show there is inequity in the availability of alcohol outlets; there are clear social patterns in the distribution of alcohol outlets with disproportionately high numbers in more socially deprived neighbourhoods. Thirdly, at the national level, after controlling for potential confounding factors, there was no association between either hazardous or frequent consumption of alcohol and access to alcohol outlets. However, there was an association for particular sub-populations in regards to hazardous and frequent consumption and access to alcohol outlets. Fourthly, although the explained variance was often quite low in outcome models for crime and hospitalisation, nevertheless most of the variance for crime was predicted by the density of alcohol outlets. A number of important theoretical and policy implications flow from this study. Alcohol outlets are modifiable structures in the environments that are amenable to policy interventions at a community and national level. Interventions could concentrate on three aspects to reduce excess consumption; zoning ordinances, reducing alcohol outlets in deprived areas and increased alcohol taxation. Starting with the first proposed intervention, zoning ordinances provide communities and local governments with the opportunity to regulate outlet numbers and locations as well as their trading hours. This intervention has the potential to reduce opportunities for obtaining alcohol. Secondly, a reduction in the number of alcohol outlets is likely to reduce consumption and consequently improve health and social outcomes. Finally, higher alcohol prices via increased taxation is likely to be a deterrent to excess consumption and related health outcomes. Three priority areas are identified and recommended for future research. Studies using a mixture of both qualitative and quantitative methods, to better understand the association between local purchases of alcohol, consumption and proximity to alcohol outlets would be beneficial. In addition, the use of qualitative methods to examine the influence of social capital and cohesion, culture and norms on alcohol consumption in areas with higher densities of, and better access to alcohol outlets, is imperative. Lastly, longitudinal studies are also recommended to investigate increases or decreases in the number of alcohol outlets over time and the impact of such changes on the consumption patterns of different sub-populations.Item Open Access The Effect of the Neighbourhood Built Environment on Obesity in Christchurch(University of Canterbury. Geography, 2009) Kumar, Anjeela MarieObesity is becoming a worldwide concern, with more than 300 million individuals who are obese and a further 750 million who are overweight. This increase is important as obesity has been linked to an increased incidence of cardiovascular disease, type two diabetes mellitus, stroke and some cancers. One factor receiving increasing attention to explain variation in obesity prevalence is the role of the built environment. This involves examining how features of the built environment such as green space or food premises vary by neighbourhood area. The presence of such resources within a neighbourhood can influence obesity through encouraging a healthy or unhealthy environment. It is important to understand how neighbourhoods influence obesity. This will allow the creation of effective public policy and urban design initiatives to reduce the obesity prevalence. Little research has examined how the quality of these resources varies between neighbourhoods and their effect on the prevalence of obesity. This thesis addresses this using a systematic site survey tool to investigate how the quality of built environment resources varies by neighbourhood deprivation. It also employs a questionnaire to examine residents’ perception of their neighbourhood as these can influence obesity through the utilisation of healthy resources. Three key findings were identified: there is a significant relationship between deprivation and the number of neighbourhood resources; the quality of these resources increases as deprivation increases; and residents in a high deprivation neighbourhood had a more positive perception of the neighbourhood. As a result, high deprivation neighbourhoods may be less likely to promote obesity as they have higher quality resources and residents have a more positive perception of the environment. These findings suggest that the influence of the built environment is context specific and that it may not be as influential on obesity in Christchurch. It highlights the need to consider both individual and environmental factors in explaining the geographic variation of obesity.Item Open Access Examining the environmental justice of sea level rise and storm tides in New Zealand(University of Canterbury. Geography, 2008) Moth, Paul DanielResearch has established that aspects of the environment are unevenly distributed among social and socioeconomic groups. While an abundance of literature documents environmental inequalities such as toxic sites, air pollution, and access to greenspace in North America and Europe, few researchers investigate coastal flooding as a result of sea level rise and storm tides. Flooding, coastal and fluvial, are the most common natural disasters in the world; and considering sea level rise and coastal squeeze, will likely become more devastating. The impacts of coastal flooding will vary between populations and often those who are vulnerable will bear the brunt of the adverse effects. This research assesses the socio-spatial distribution of sea level rise in combination with storm tides in New Zealand, taking into account factors such as gender, age, income, ethnicity, and deprivation. Results display that the distribution of risk to coastal flooding is disproportionately higher in environmentally vulnerable places, such as coastal urban low-lying areas, and among socially vulnerable populations, such as Pacific peoples, people aged 65 and over, and people of low-income and high deprivation. Research also exhibits variations for each region in New Zealand. Discussion of the results are placed into context with the existing social, income, and health inequalities in New Zealand and the areas where inequality to coastal flooding in the highest. Furthermore, the results are discussed in relation to the policy framework in New Zealand including the New Zealand Health Strategy 2000 and the Resource Management Act 1991. The argument demonstrates that the regulatory framework in New Zealand fails to recognise environmental justice or environmental inequalities. Lastly, the limitations of research are discussed as well as recommendations for further environmental justice research in New Zealand.Item Open Access The health effects of PM₁₀ air pollution in Reefton, South Island New Zealand.(University of Canterbury. Geography, 2009) Brown, Michael JamesThe aim of this thesis is to assess the health effects of PM₁₀ air pollution in Reefton which is located on the West Coast of the South Island, New Zealand. Two principle objectives were investigated to achieve the overall aim. Firstly, whether there is a link between PM₁₀ exposure and increased respiratory and cardiovascular hospital admissions in Reefton. Secondly, the evaluation of whether PM₁₀ pollution exacerbates selected health symptoms associated with PM₁₀ exposure among study participants during a short term cohort study within Reefton. To address the first research objective, data for respiratory and cardiovascular hospital admissions were collected and comparisons were made with past-till-present PM₁₀ levels monitored in Reefton. The second research objective was carried out during a four week period in July 2008 in Reefton. A total of 78 people from the general population participated whereby they recorded their daily health status in a symptoms diary. Symptoms monitored included phlegm build-up, coughing, breathing problems, wheezing, throat discomfort, and eye irritation. Associations between PM₁₀ exposure and exacerbation of health symptoms among participants were examined through statistical analysis. Results showed no clear link between PM₁₀ exposure and increased respiratory and cardiovascular hospital admissions. The lack of association could be attributed to the limited amount of PM₁₀ data available for comparison, along with the low number of hospital admissions in Reefton due to the towns’ small population. Conversely, several associations were observed between PM₁₀ exposure and specific health symptoms among study participants. Associations were frequently small and positive while several reached statistical significance. In conclusion, PM₁₀ air pollution in Reefton could not be linked with an increase in respiratory and cardiovascular hospital admissions, however it was associated with the exacerbation of several health symptoms known to be aggravated by exposure to PM₁₀.Item Open Access Population mixing and the geographical epidemiology of childhood leukaemia and type 1 diabetes in New Zealand(University of Canterbury. Geography, 2008) Miller, Laura JeanOver the past twenty years the incidence of both childhood acute lymphoblastic leukaemia (ALL) and type 1 diabetes have risen in many developed countries, including New Zealand. Although the explanations for this increase and the precise aetiology of both diseases remain unclear, environmental factors are thought to be important. One factor receiving increasing attention is the role of infections introduced through population mixing. However, previous studies on this topic show mixed results and population mixing itself tends to be under-theorised. Furthermore, this issue has not been adequately assessed in New Zealand, a country characterised by high levels of population mobility. In this research, a variety of population mixing measures for small areas in New Zealand were developed. National data on ALL registrations were obtained from the New Zealand Cancer Registry, and regional type 1 diabetes data were obtained from the Canterbury Diabetes Register for the Canterbury Region of the South Island. The analyses were undertaken in three stages. First, standardised incidence ratios of each disease were examined at different geographical and temporal scales, between areas of differing socioeconomic status, and in urban and rural New Zealand. Second, cluster analysis was employed to test for spatial-temporal clustering of the two diseases. Finally, multivariate regression analyses were utilised to investigate the association between each disease and the various measures of population mixing at the area-level. The results reveal similarities in the geographical epidemiology of childhood ALL and type 1 diabetes in New Zealand. The majority of the findings were suggestive of an infectious aetiology for both diseases. In addition, higher incidence of both diseases was observed in areas which increased the most in population mixing over short time periods (6/7 years). Furthermore, raised type 1 diabetes incidence was also associated with high population mixing in early life.Item Open Access Investigating the spatial distribution of campylobacteriosis in New Zealand(University of Canterbury. Geography, 2007) Rind, Esther ChristianeBackground Infection with Campylobacter is thought to account for about 5% - 14% of all food and waterborne diarrhoea cases worldwide. By international standards, New Zealand has extremely high rates of campylobacteriosis which are thought to be the highest reported rates worldwide. The incidence has been steadily increasing since 1980 (when the disease became notifiable), reaching a peak of cases in 2003 (396/100,000). Although different surveillance systems complicate international comparisons, New Zealand's particularly high rate still lacks a conclusive explanation. Aims This study investigates the geographical distribution of campylobacteriosis in New Zealand and the relative importance of factors assumed to be affecting the distribution of this disease, including those related to climate, landuse, water and food. The approach aims to explain why certain areas might increase the probability of becoming infected. Methodology A Geographical Information System (GIS) is used to visualise the disease rate, investigate potential disease clustering and identify outliers. Hierarchical regression, including the analysis of residuals, is applied to analyse the variables in their complex interrelation and to investigate whether there is statistical evidence explaining the geographical variation in campylobacteriosis. This study is undertaken at the territorial local authority level, as all required data are available at this spatial scale and covers the period 1997 to 2005. Results and conclusion There is a large geographical variation in campylobacteriosis across New Zealand, ranging from an average annual rate of 97/100,000 to 526/100,000 per territorial local authority (TLA). Generally, there is statistical evidence for global and local clustering of the disease rate. There are upper and lower outliers of campylobacteriosis in New Zealand; however, higher rates primarily appear in the South Island. The hierarchical modelling confirms statistical significance for some of the environmental and sociodemographic variables. The final model explains about 58% of the variation in campylobacteriosis, and the residuals reflect this variation relatively accurately in approximately 75% of all TLAs. Although the evaluation of the results is confronted with a number of challenges, it is concluded that socioeconomic and demographic factors are crucial factors in explaining the observed spatial patterns in the notification data.