Report on GIS and public health spatial applications

Transcription

1 Report on GIS and public health spatial applications Disease ecology is inherently integrative and spatial, and GIS provides the environment in which the biophysical, social, behavioural, and cultural worlds can be combined for a systemic understanding of health and disease. 1 Public Health Services Branch Queensland Health - 1 -

2 Queensland Health 2005 Copyright protects this publication. However, Queensland Health has no objection to this material being reproduced with acknowledgement, except for commercial purposes. Permission to reproduce for commercial purposes should be sought from the Policy and Quality Officer, Queensland Health, GPO Box 48, Brisbane Q Acknowledgments of contributing authors: Victorian Department of Human Services data used with permission of Dr Robert Brazenor This document is available on the Queensland Health Internet site Suggested citation Queensland Health: Hart A, McCulloch B, Harper C, Gardiner N, Rutherford S, Baker P, Harris P, O Sullivan D. Report on GIS and public health spatial applications, Public Health Services, Queensland Health. Brisbane For further information: Population_Epidemiology@health.qld.gov.au Cover Page: Map illustrating Queensland by Health Service Districts (2001) - 2 -

3 Table of contents Report on GIS and public health spatial applications...1 Table of contents...3 Table of figures...4 Introduction Public health and GIS literature review Preface Communicable disease control Environmental health research, planning and operations Nutrition and physical activity Physical activity Nutrition Child and youth health Health promotion Chronic disease prevention Alcohol tobacco and other drugs service (ATODS) provision Injury Mental Health Vector control Communication/public engagement Public health service planning Limitations of applying spatial information and techniques in public health and epidemiology References...55 Appendix A - List of abbreviations used

4 Table of figures Figure 1: A subset of John Snow s 1854 Cholera map, showing incidence of Cholera around the infamous Broad Street pump Figure 2: Meningococcal incidence and deprivation superimposed, Norwich. 49 Map provided courtesy of author, Ms Chris Williams (kitwilliams@nhs.net) Figure 3: Computer-simulated exposure of dioxin from three sources (red) are layered onto the electronic map (GIS) and seen as different coloured bands, with highest dioxin immissions in bright red and lowest in faint green. The immission concentration band borders (blue) are used to demarcate the three zones used for analyses of cancer development Figure 4. Mean number of non-auto trips based on age of neighbourhood Figure 5. Access to Parks in Norwood, SA Figure 6. Index of walkability in Adelaide, SA Figure 7. A geographic information system map of Moses Lake, WA, outlining the convenience of healthy food choices in relation to local schools (the area is designated by the Buffer 1 of Schools.shp). The larger the circle, the more healthful choices available Figure 8: Cost of a nutritious food basket as a proportion of mean household income and children (0-6) served by food banks in Vancouver Figure 9: Kindergarten dental screening, proportion of children found to have evidence of nursing bottle tooth decay, 1998/ Figure 10: A dynamic map of the 2000 lead poisoning rate per 1000 children aged 6-72 months in Massachusetts. This map has rates mapped to census block level and can have county outlines and streets added by the user to give the map some geographic context Figure 11. A Behavioural Risk Factor Surveillance System map illustrating by State the 2002 percentage of respondents who answered yes when asked Do you smoke cigarettes now? Figure 12: A MassStats map displaying incidence of all types of cancer relative to expectations Figure 13. Example of the output of the SEP and IDU GIS model in Manhattan City Figure 14: A DFSS map showing cases of dengue fever (including the case age bracket and confirmation status) and vector control work done (including type and age bracket) 10. Note: this is an artificially constructed map, using false data to illustrate the functions of this DFSS product Figure 15. Probability that kriged mosquito numbers per trap throughout mainland and Macleay Island areas of Redland Shire exceeded the 75th percentile each week, during 2000 (n _ 11) and 2001 (n _ 4) sampling periods Figure 16: A map on the cover page from the New Zealand Public Health Surveillance Report Figure 17: Proportion of children (5-14 years) in Gold Coast HSD, compared to Queensland, by collection district, Figure 18: Beechworth community profile from the Victorian Department of Human Services website Figure 19: A health service planning map highlighting travel time to hospitals. The lighter the background colour the longer the travel time from hospital Figure 20: A map showing the types of data that could be presented for health service planners. Picture courtesy Dr Robert Brazenor, Victorian Department of Human Services Figure 21: Health Status and Services map displaying health facilities by facility code and projected population change (%/pa)

5 Introduction Background Geographic Information Systems (GIS) have been identified as a potential tool to inform decision making in several areas of Queensland Health. Historically, public health information (surveillance) systems, based in local, state and commonwealth governments, have collected and tabulated data on illness, disabilities, causes of death, injuries, behavioural and environmental risk factors, health costs and other health issues 2. Globally, improvements to both the spatial analysis tools (sophisticated software and fast personal computers) and the quality and accessibility of the information itself (unique identifiers, digital census data, rapid internet), have led to the increasing use of GIS when considering associations between causative influences in their geographic context and public health outcomes. 3-8 Application of spatial information GIS has been successfully applied in many areas of population health. Applications have included informing the placement of water pumps in villages most infected by Guinea Worm to ensure a safe water supply 6, enhancing community-based child welfare services 9 and identifying culturally appropriate health promotion material distribution points for diabetes literature in a multicultural community. GIS has also been used in the surveillance and monitoring of vector-borne 10 diseases, quantifying lead hazards in a neighbourhood 11, predicting child pedestrian injuries 12 6, 13 and analysing disease policy and planning. These applications have been integral in the development of targeted interventions leading to the following better health outcomes and/or reductions in the cost of service provision respectively; by reducing the prevalence of guinea worm in villages where pumps were introduced 6, by ensuring that children in high child poverty areas receive subsidised meals whilst at family day care 11, by helping target a culturally-sensitive diabetes program 14, by directing a finite vector control resource to the highest priority response areas during dengue fever outbreaks, by directing lead screening programs to ensure comprehensive screening in high-risk neighbourhoods whilst reducing overall costs 11, by locating clusters in space and time of child pedestrian injuries 12 and suggesting intervention sites. It is clear that GIS technology on its own does not usually deliver better health outcomes. By informing epidemiologists, policy and decision makers, and health workers of the location and geographic relationship between datasets, GIS helps target existing interventions to improve the efficacy of the service delivered, or reduce costs associated with service delivery. 5 Spatial information and public health are so inter-related that New Zealand s Ministry of Health (MoH) announced in early February 2005 that it was opening a GeoHealth laboratory at Canterbury University in a joint venture between the Department of Geography and the Public Health Intelligence group (PHI) of the MoH. 15 Research currently being undertaken by the GeoHealth laboratory includes studies into why New Zealand has the highest incidence of melanoma in the world, assessment of road traffic accident reduction policy initiatives and the ethnic differences in New Zealanders smoking habits. Recent research has highlighted that smoking is highest among the most - 5 -

6 socially deprived communities in New Zealand with particularly high rates among Maori. Similarly, other work with Diabetes New Zealand has found that diabetes rates are significantly higher in New Zealand s poorest communities, and among Maori and Pacific Island communities. Other studies have found that both the exposure to and health consequences of air pollution in Christchurch are far higher in the poorest neighbourhoods. 15 This information provides insight for health workers when developing policies and planning interventions. In collaboration with other government departments, it could also provide a focus for land use changes, public education, transportation funding, financial reform and political advocacy Despite the fact that modern GIS technology, including software and fast personal computers, has been available for at least a decade and contains much promise, the incorporation of GIS data, methods and software into public health management and practice is just beginning. 5 Queensland Health Within Queensland Health there exists a defined opportunity to use spatial information to permit a more reasoned neighbourhood-based approach to the development of effective interventions, as a result of the better understanding of place and its relation to other etiological variables. The literature contains many applications of spatial information in public health that have had a positive impact on the identification and management of, population health issues. Barriers to the uptake of spatial information to inform decision making within health agencies include lack of geographical precision, legislative (confidentiality) restrictions, inaccessibility of data (including data external to Queensland Health), knowledge and confidence in spatial analysis techniques 18 by epidemiological staff; and accessibility to software and skills to undertake spatial analysis of data. There are a wide range of potential benefits should spatial information be made available and analytical techniques applied within Queensland Health. These include linking and integrating multiple datasets rapidly and accurately, portraying data analysis on a map, thereby providing an understandable visual picture of population health outcomes and determinants. In addition, the presentation of community statistics in a spatial environment allows the policy maker and healthcare worker to compare different 'like' communities and to examine differences in both health status and access to health services using thematic maps. 19 Spatial presentation also allows identification of clustering of communities that share similar characteristics, in relation to health status or use of health services, and may help reveal the common contributing covariates. 19 While many program managers may already have a good sense of the geographic determinants of the health conditions of the population they are serving; they may not be familiar with relevant but less health-related variables such as the age of housing stock, public transport routes, or locations of schools and senior centres. 7 Historically within Queensland Health, timely access to relevant, geographically accurate information and tools, to consider an event in its geographical context has been limited. In many cases, needs may have been satisfied using existing datasets, but which lacked spatial infrastructure

7 The capacity to undertake and present complex data analysis in a spatial environment would allow a higher level of understanding of the information that already exists, resulting in better-informed decision making and improved work flows 20 within Queensland Health. However, to implement spatial information use in Queensland Health in a coordinated manner, we must overcome the primary barriers. These are poor geographic data quality and accessibility, sparse geographic analysis skills, and GIS software availability and maintenance

8 1.0 Public health and GIS literature review 1.1 Preface A literature review was conducted during November and December The aim was to document existing applications of spatial information use within the area of public health globally. The review was done primarily using Ovid Medline and supplemented with PubMed to identify relevant journal articles. Keywords used in the search included geography, map, GIS, health, public, disease, alcohol and drugs. The review was supplemented with information from public health agency and university websites, textbooks, conference and forum proceedings and presentations, and information booklets printed by both healthcare agencies and software companies. There is a significant volume of information on spatial information applications within public health, ranging from assessing health facility placement to creating communicable disease early warning systems 25 for infectious diseases such as West Nile Virus. By far the most frequent references were regarding the generation and statistical evaluation of associations between health outcomes and social, environmental and economic factors The large volume of information published on this area is likely due both to the variety of spatial applications for epidemiological information and also the requirement for rigorous evaluation of spatial associations using appropriate epidemiological science (eg. case control and cohort studies). The latter is required as most GIS analyses assessing whether there is an association between geography and a health outcome will find one. Usually, however, health outcomes will cluster geographically because of the underlying population characteristics, not because of the (environmental/physical) geography itself. 5 Improved and accessible spatial application of information will provide considerable public health benefit. In addition, the application of spatial epidemiology will provide benefits for service delivery in other areas of the health sector. For example, better identifying and locating the existing services provided by Queensland Health could be used to improve accessibility to services by population subsets and would also allow GPs to easily refer patients to the closest relevant clinical service. At the same time, health service information can be used by health service planners to optimise the location of future health services and by workforce reform managers to streamline the human resource needs of a health facility. Further, the same information may be used to better plan for disaster management and to determine geographical barriers to health service access. This literature review provides examples of GIS and identifies their potential application in the following public health related areas. Communicable Disease Control Environmental Health Research, Planning and Operations Nutrition and Physical Activity Child and Youth Health Health Promotion Chronic Disease Prevention - 8 -

9 Alcohol, Tobacco and Other Drugs Service (ATODS) provision Injury Mental Health Vector Control Communication/Public Engagement Public Health Service Planning For convenience, throughout this review applications have been categorised into the above public health related areas. This literature review offers examples from the above information sources on the key areas for which GIS may be used to improve health outcomes. It is divided by a loose collection of Outcome Area Team areas and functional units within Public Health services

10 1.2 Communicable disease control Background Besides time and person, knowledge of the spatial distribution of communicable disease cases is essential in understanding disease transmission and determinates. Many diseases not caused directly by environmental exposure still cluster geographically. 5 Influences on non-uniformity of disease distribution include physical and environmental factors, social, economic and cultural factors and genetic factors. 52 The integrative features of GIS are incredibly helpful in summarising the complex relationships between communicable-disease pathogens, associated vectors and reservoirs, the environment, and human populations. 5 John Snow s cholera study served as a good example of how geographic mapping could provide new insights into communicable-disease aetiology and intervention, helping disease control efforts. 5 Although his map alone did not determine the cause of the 1854 cholera epidemic, it served as a useful tool to summarise his findings and convince his contemporaries of his conclusions. 5 Figure 1: A subset of John Snow s 1854 Cholera map, showing incidence of Cholera around the infamous Broad Street pump. 53 By displaying cases of cholera along a street frontage (Figure 1), Snow made a local street level map that showed only the numerator and did not take the underlying population data into account, therefore failing to provide disease rates as would be expected by modern epidemiologists. 3 Applications of spatial information Epidemiological data and public health resources once mapped, can be integrated with other existing databases including socio-economic (eg. age of population), environmental (eg. vector habitat) and infrastructure (eg. transport routes and accessibility) data, and

11 spatially analysed to provide intelligence for epidemiological research and communicable disease control. 54 In addition, community profiles, containing a snapshot of geography, human services and facilities, population age breakdown, population growth and decline and social and health characteristics, allows epidemiologists to build a picture of how a community compares with similar communities on a range of dimensions. 55 For a more complete review of community profiles, please refer to the Public Health Service Planning section of this literature review. Potential uses for GIS and spatial information within Communicable Disease Control 3, 43, 55 include: case distribution mapping (incidence/prevalence of notifiable conditions) identifying spatial patterns in disease distributions through statistical modelling identifying spatial relationships and causal factors in disease distributions generating data for input into epidemiological models initiating the generation of hypotheses relating to etiology of disease support decision making for creating and targeting disease interventions communicating known health determinants and outcomes visually for outbreak control teams quantifying the impact of disease intervention programs generating statistics for inclusion in community and Local Government Area (LGA) profiles. Data sources Automated GIS that collect, analyse and map all reportable communicable diseases promise to improve the efficiency of disease control efforts. Such systems can incorporate multiple sources of data, such as: 5 routine mandated notifiable disease reports special communicable-disease studies, such as active surveillance by hospitals for nosocomial infections results of active surveillance for sentinel infections, such as drug-resistant infections in hospitalised patients data produced by collaborative research between public health agencies and the private sector, including managed care organisations

12 other sources of communicable disease data, such as Medicare billing data datasets from other government agencies, eg. alcohol-related motor vehicle accidents, property boundaries, census data. Applications for spatial information An existing use for GIS within Queensland Health is the Dengue Fever Surveillance System. It is an automated GIS/Database system that collects, analyses and maps cases of dengue fever and vector-control work conducted in response to dengue fever incursions and outbreaks. 10 It is noted that the Australian Department of Health and Aged Care has identified data visualisation in the form of maps as one the benefits and outcomes of the Secure Outbreak Case Reporting System sub-project of the Biosecurity and Surveillance Project. 56 Further, disease mapping has been identified as one of the tools to improve analysis and reporting 56, 57 within the National Notifiable Disease Surveillance System. The following are examples of the application of spatial information and GIS in communicable disease studies, either disease mapping (primarily descriptive mapping) or geographical correlation studies (more focussed on aetiological questions). Geocoding addresses (assigning mapping coordinates) of disease incidence to assist in environmental epidemiology studies. 36 Studying the global distribution of infectious diseases (West Nile, SARS, Monkey pox) and developing predictive outbreak models. 25 Assessing the geographic relationship between alcohol availability and high risk sexual behaviour at the neighbourhood level (using gonorrhoea rates as an indicator) in New Orleans. 58 Providing STI hotspot surveillance with an interactive cyber map for London s Primary Care Trust healthcare workers. 59 An ecological study on the geographic correlation between deprivation and meningococcal disease in the UK. 50 Figure 2 shows rates of meningococcal disease and an index of deprivation by ward in Hertfordshire and west Essex. There is an association between areas with a high deprivation score and increased rates of meningococcal disease. The authors of this paper suggest the direct impacts of deprivation may be reduced access to quality childcare, increased incidence of smoking in the home, and simply higher rates of children and young parents in these wards. The ABS product Index of Relative Socio-Economic Disadvantage (IRSED) could provide similar background data for disease comparison with deprivation here in Australia. 60 In Baltimore County, Maryland, GIS and epidemiologic methods were combined to identify and locate environmental risk factors associated with Lyme disease. 61 Ecologic data such as watershed, land use, soil type, geology, and forest distribution were collected at the residences of Lyme disease patients and compared with data collected at a randomly selected set of addresses. A risk model was generated combining both GIS and logistic regression analysis to locate areas where Lyme disease is most likely to occur. 6 Mapping has also been used in conjunction with information of the

13 performance of a diagnostic test (sensitivity and specificity) to prepare guidelines for the screen of Lyme disease. 62 Figure 2: Meningococcal incidence and deprivation superimposed, Norwich. 50 Map provided courtesy of author, Mr Chris Williams (kitwilliams@nhs.net). Crown Copyright, ED-LINE Consortium through UK Borders

14 1.4 Environmental health research, planning and operations Background Environmental health epidemiology can be studied through familiar, causal epidemiological study designs such as case-control studies, cohort studies and nested case-control studies within cohorts. Additionally, geographic studies more specifically, ecological or geographic correlation studies and studies of disease clusters are particularly pertinent to environmental epidemiology, especially in relation to the identification of specific hazards. 63 Consequently, geographic information systems are being used with increasing frequency in environmental epidemiology studies. 36 Environmental health epidemiology allows systematic study of environmental factors on human health. The two approaches to study the influence of the distribution and determinants of environmental factors on human health are the disease driven approach and the exposure driven approach. 63 Applications of spatial information Although most GIS-based studies have been ecologic in design, some have used GIS in estimating environmental levels of a contaminant at the individual level and to design exposure metrics for use in epidemiologic studies. 36 The following are published examples of the application of spatial information and GIS in environmental health. Evaluation of the influence of geological factors and natural gamma radiation on indoor radon concentrations in Spain and Norway and 40, 48 subsequently outlining areas of high-radon risk. The spatial analysis of annual air pollution exposure and mortality in Auckland, NZ. Subsequent production of GIS based exposure maps identify high exposure areas for policy developers and planners in a simple and realistic manner. In combination with overseas studies, this study provides further evidence of the hazards of poor air quality to human health. Interestingly, this study confirmed a previous study s findings regarding deaths attributable to air pollution in Auckland. Approximately twice the number of people are estimated to die from non-external causes and circulatory and respiratory causes attributable to air pollution than those who die from motor vehicle accidents in the same region. 45 Investigating the etiology of asthma prevalence and residential exposure to air pollution at a major United States Canada border crossing. This study found clustering of asthma cases in close proximity to the high volume traffic areas and a dose-response relationship indicating a decreased risk of asthma prevalence the farther an individual resides from the source of exposure. 38 Interestingly, a sharp decrease in traffic after the September 11, 2001, World Trade Centre terrorist attacks was associated with a decline in health care use for respiratory illnesses which rebounded when traffic recovered. 64 The evaluation of human exposure to ambient fine particulate matter (PM10) in the metropolitan area of Mexico City. In this study, the data from pollutant measurement stations across Mexico City were interpolated to

15 provide a continuous contour range across the metropolitan area that could be used over the long term to monitor the efficacy of interventions designed to reduce the incidence of exposure to harmful levels of PM10. Population localities by municipality were also mapped and associated with the corresponding air quality value to determine exposure rates across the metropolitan area. Pollution control scenarios and their impact on air pollution were also modelled (using a five year data baseline), to provide forward projections on the impact of pollution control on incidence of asthma by age group in the population. 27 The application of GIS to elaborate on nitrate, arsenic and chloride pollution of drinking water in Thessaloniki, Northern Greece. This application highlighted the association of elevated nitrate levels in the groundwater with areas of high nitrate-based agricultural fertiliser application. It also highlights the intrusion of seawater into aquifers in areas of intensive freshwater irrigation raising the level of chloride contamination. As the main sources of drinking water supplies in Greece are groundwater aquifers, excessive pollutant levels in groundwater are seen as a hazard to human health. 65 Describing the spatial and temporal distribution of Escherichia coli among humans (EHEC) and cattle (VTEC) in Sweden by an ecological study, in order to evaluate relationships between the incidence of EHEC in humans, prevalence of VTEC O157 in livestock and agricultural structure. The mapping and comparison of distributions of human and cattle infection indicated a spatial and statistical association. A significant statistical association of cattle and farm density with human association was indicated by a high correlation between variables of agricultural structure and human EHEC incidence. This study suggests that it is not the nationwide distribution of industrially processed food, as reported for many outbreaks worldwide, eg. in the United States 66, but predominantly the spatial contiguousness to farms and cattle and different opportunities for contact with faecal contamination that seem to be important for EHEC transmission in Sweden. 33 GIS was used in Hong Kong to identify soil contamination hot-spot areas and to assess potential pollutant sources in an urban community. Geochemical maps were produced of total metals (Cd, Cr, Cu, Ni, Pb and Zn) using a systematic sampling strategy of 3-5 composite soil samples (0-15cm) per km 2. The production of these maps used GIS to locate the sampling locations in the study area and generate the geochemical maps showing hot-spots of metal contamination in soils. GIS was also used to analyse the correlation between the soil metal index and road networks, locations of industrial buildings, buildings and landscapes using GIS spatial analysis techniques (eg. overlay analysis). The study demonstrated that GIS can be used in a study of urban soil contamination to produce geochemical maps, identify hot-spot areas and assess the potential sources of pollutants in an urban community. 67 Exploring the relationship between mortality from cardiovascular and cerebrovascular disease and drinking water hardness in Spain using the European Environment and Health Information System s (EUROHEIS) Rapid Inquiry Facility

16 Conducting exploratory spatial data analysis for the identification of risk factors to birth defects in China uncovering two clustering phenomena, socioeconomic activity and soil type distributions. 51 Integrating an exposure model for airborne dioxin with individual data on addresses, sex, age, migration and information from routine health statistics (Danish Cancer Registry) proved its usefulness in demarking the exposed population (Figure 3) and identifying the cancers related to that population. 39 Figure 3: Computer-simulated exposure of dioxin from three sources (red) are layered onto the electronic map (GIS) and seen as different colored bands, with highest dioxin immissions in bright red and lowest in faint green. The immission concentration band borders (blue) are used to demarcate the three zones used for analyses of cancer development. 39 However, researchers and epidemiologists using a geographic study approach should be cautioned that since ecological studies are based on aggregate or group level exposures, and not individual exposures, inferences from ecological studies are directly applicable at a group or aggregate level alone. Unwary attempts at extrapolation to individuals could result in erroneous attempts characteristic of the ecological fallacy

17 1.5 Nutrition and physical activity Physical activity Background Environmental factors play an important role on influencing physical activity (PA) behaviours. 68 Despite this recent association and the obvious benefits of collating and analysing disparate datasets (eg. year of neighbourhood development and association with obesity), reported applications of GIS in this area are relatively limited. Whilst GIS has been used to identify cross sectional observations/associations between areas of low walkability and higher rates of obesity and sedentary behaviour, there has been no research yet on interventions to determine that they have increased walkability Applications of spatial information Research has demonstrated how built environments affect our health by influencing our patterns of travel and consequently the air pollution we generate and our own physical activity. 17 Associations between the age of a suburb/development and the curvyness of the street network were found. The older a suburb is, the more likely it is to have a grid like street network and consequently a higher mean number of non-motorized trips (Figure 4). The more curvy a street network is, the higher the street-block area in square metres. This decreases community connectivity, and increases both the number of trips and the average length of each trip undertaken by vehicle. 17 Figure 4. Mean number of non-auto trips based on age of neighbourhood

18 GIS has been used (in combination with travel survey data) extensively to compare and very effectively illustrate a number of indicators of community walkability in older and newer suburbs in Georgia, USA, including: 17 daily per capita home-based vehicle miles per trip the average distance travelled for recreation settlement density calculating sub-trip components and emission estimates Nitrous Oxide (NOx) emissions based on street connectivity proximity of commercial services (retail area) to residential areas assessment of latent demand Frank (2003) found that 33% of people who do not currently live within a few blocks (1/3 mile) of commercial areas would like to live in this sort of walkable neighbourhood. These statistics could provide a focus for land use changes, public education, transportation funding, financial reform and political advocacy. 17 A similar GIS-based approach to assessing community walkability has been replicated by a research group in Queensland in the PLACE ( Physical Activity in Localities and Community Environments ) study that extends beyond the example above. The goal of the PLACE study is to understand the factors that influence the prevalence and both the social and spatial distribution of physical activity, particularly walking for transport and walking for recreation and exercise. 72 The National Centre for Social Application of GIS (GISCA), in collaboration with the PLACE researchers, have developed an index to measure the walkability of Australian cities, using a variety of geographical indicators (ie. access to parks, hilliness, proximity to retail areas, residential density, etc.). 73, 74 GISCA links walkability of an area to the levels of physical activity of its residents. Some of GISCA s work is illustrated in figures 5 and 6 below

19 Figure 5. Access to Parks in Norwood, S.A. 73 Figure 6. Index of walkability in Adelaide, S.A

20 The Liveable Neighbourhoods Policy Review undertaken by the West Australian Planning Commission, identifies physical activity as an emerging urban issue, related to obesity and poor health. 75 Shaping Up, a guide to the better practise and integration of transport, land use and urban design techniques, is focused on South East Queensland and allows Queensland Health to collaborate with Queensland Transport and its partners to promote development in the future with active transport in mind. 76 Shaping Up identifies that land use planning can dictate that car travel is the only viable means for both short and long distance travel. Alternatively, land use planning can encourage land use patterns that support the use of public transport, cycling and walking. 76 Discussion Identifying the environmental factors that may act to influence walking and cycling will allow the inclusion of a public health perspective, as well as those of urban planning and transport, in the design of built environments. 77 GIS could assist health promoters to evaluate the contribution of environmental attributes and their interaction with other factors, to better understand how to influence physical activity behaviours in Queensland Nutrition Background The key issues for nutrition and GIS are being able to visualise food accessibility and availability and their association with people s behaviour. 76 Nutritionists need to identify relative accessibility and availability to food and the impact that remoteness has on healthy food prices and consequently, people s food choices. Healthy food access and availability is not just an issue for remote areas. A by-product of urban sprawl has been the emergence of food deserts, where residents do not have access to healthy food choices within walking distance and must rely on motorised transport to conduct their shopping. 78 Providing a GIS for nutritionists involves mapping community food assets (and liabilities) including supermarkets, 24 hour shops and fast food outlets. It also requires mapping schools, communities and residential areas, and the Accessibility and Remoteness Index for 26, 76 Australia (ARIA). Traditional analysis and techniques may be suitable for understanding patterns within small groups, but sometimes the large volume of data can be overwhelming to organise and interpret. As a result, many nutritionists are turning to geographic information systems (GIS) to understand patterns better. 26 Applications of spatial information Researchers at the University of British Columbia, Vancouver, indicate the best thing about GIS is that it gives dietetics professionals the ability to see how different factors influence each other

21 GIS has the potential to assist the study of spatial relationships between food availability and dietary choices. There are many questions that can be asked if GIS is combined with surveys of the dietary behaviours of community residents. For instance, how close does a supermarket have to be to make a difference in food choices for those who do not drive? 26 The University of Washington used a GIS to map the small city of Moses Lake, WA, to better understand the city s health environment. A GIS is a great way to get people to consider the impact of access to food and the spatial relationship with food systems. 26 Figure 7 illustrates school students access to healthy food choices in the neighbourhood. Figure 7. A geographic information system map of Moses Lake, WA, outlining the convenience of healthy food choices in relation to local schools (the area is designated by the Buffer 1 of Schools.shp). 26 Whilst considering food access (and barriers to healthy food choices), the statistics generated here in Queensland by the public health nutritionists and presented in the Healthy Food Access Basket (HFAB) Survey Reports can provide a basis for change in food access. Results from the HFAB survey confirm that food supply monitoring can provide the basis for advocacy by assisting to highlight disadvantaged areas to key partners who have the ability to influence the food supply. 79 The spatial information component of this report is primarily in the analysis of the results based on the relevant score in the Accessibility/Remoteness Index of Australia (ARIA).There was a strong association between ARIA category and the cost of the basket of basic foods, with prices being significantly higher (20% and 31% respectively) in the 'remote' and 'very remote' categories than in the 'highly accessible' category. 79 GIS has a role to play in HFAB surveys, both in terms of presenting the data in the survey report 80 and also determining accessibility/remoteness with a finer resolution using spatial interaction modelling 81 or a similar technique

22 North Carolina Department of Health and Human Services are using GIS for analysis in their attempts to reach 1.3 million women at child-bearing age for their Folic Acid Project. Each neighbourhood has been assigned to a geographic cluster or neighbourhood type, based on urbanisation, mobility, housing and other factors. The public health nutrition consultants can then use different outreach techniques based on which cluster/with whom they are dealing. 26 As part of Clyde Hertzman s work to raise the importance of early childhood development as an indicator of lifelong health, he has used GIS to map the determinants of early childhood development, and refers to the cost of a healthy food basket as a proportion of mean household income across Vancouver, BC. Figure 8 illustrates the cost of access to healthy food expressed as a percentage of mean household income varies from 11%-66%. 82 children (0 6) served by food banks Figure 8: Cost of a nutritious food basket as a proportion of mean household income and children (0-6 years) served by food banks in Vancouver

23 1.6 Child and youth health Background Contemporary child and youth health research describes a complex interplay of genetic, social, environmental, economic and cultural factors in childhood and adolescence, and their effects on health in adult life. 84 For example, in a national sample of Canadian preschoolers, children's verbal ability scores were positively associated with residing in neighbourhoods with affluent residents and negatively associated with residing in neighbourhoods with poor residents and in those with low cohesion, even after controlling for family socioeconomic factors. Behavioural problem scores were higher when children lived in neighbourhoods that had fewer affluent residents, high unemployment rates, and low cohesion, after controlling for family socioeconomic factors. 85 Given the wide range of factors impacting on childhood and adolescent development, GIS could serve as a medium to allow examination of these factors and the interrelationship they have with young people s development. Despite the growing evidence of the association between early childhood development and lifelong health, there are few reported applications of spatial information to further inform interventions in this area. Applications of spatial information Professor Clyde Hertzman has used GIS extensively to help map a number of contributing factors to provide a picture of early childhood development in Vancouver. 83 Distribution of young children in communities. Costs of a nutritious food basket by community. This was then correlated with childhood distribution to help the education department better target food assistance programs. Distribution of developmental indicator differences in children, highlighting communities with vulnerable children. Use (uptake) of medical services in the first year of life. There is a disproportional relationship with birthweight for gestational age. There is also an association between accessing healthcare more frequently in childhood and living a longer healthier life with less frequent healthcare access events in adulthood. Mapping dental screening records of the distribution of early childhood caries (nursing bottle tooth decay). Distribution of single income or single parent households. Access to formal childcare correlated with mean household income looking at formal childcare opportunities (seats in childcare) per district and also the number of children per district

24 Averaging the core skills test at the neighbourhood level and comparing neighbourhood performance. Also used to evaluate institutional performance in relation to average childhood development within the catchment and in relation to the socioeconomic indicators within the catchment. Figure 9 provides an example of the type of Early Childhood Development Indicator mapping available as part of Professor Hertzman s Community Asset Mapping Project ( a component of the Human Early Learning Project (HELP) ( also directed by Hertzman. 82 bo e oo decay, 998/99 Figure 9: Kindergarten dental screening, proportion of children found to have evidence of nursing bottle tooth decay, 1998/ The following are other examples of existing applications of spatial information in child and youth health. Mapping household crowding and the incidence of meningococcal disease in children in Auckland, NZ. Once this data was presented to Housing New Zealand, a program commenced to add more rooms to houses in areas where tenants have large families. 86 Mapping deprivation and meningococcal disease in England. Incidence of meningococcal disease was highest in the most deprived wards, with a relative risk of 1.97 ( ). Mapping revealed geographical coincidence of deprivation and meningococcal disease, particularly in urban areas. Two-thirds of the increased incidence was due to cases in the under fives. The study concluded that area deprivation is a risk factor for meningococcal disease, and that its effects are seen most in young children. 50 A map of meningococcal incidence overlaid on a deprivation index by census ward is provided as an example in section 1.3 Communicable Disease Control (page 14)

25 Mapping Queensland Health s services for children and young people aged 0-24 years. This project seeks to identify services provided by or funded by Queensland Health, describe the extent and other attributes for these services, and map the community-based component of these services against a model of care for community child health services. The outcomes are to identify the overlaps and gaps in service provision, provide a solid information base for further funding submissions, and develop a guide for the purchasing and provision of children s and young people s health services in Queensland. 87 Examining children s exposure to traffic related pollutants by mapping proximity of public schools to busy roads in California; also looking at the relationship between exposure and race/ethnicity and socioeconomic status. The study found that a substantial number of children in California attend schools close to major roads with very high traffic counts, and a disproportionate number of those students are economically disadvantaged and nonwhite. The paper goes on to suggest some mitigating interventions, ranging from school placement to school design. California recently introduced legislation to prohibit siting new schools within 500 feet (168m) of a busy road. 29 Determining the association between blood lead concentration (Pb-S), and sociodemographic parameters among children in Venezuela. The data was mapped with a GIS and confirms that GIS and epidemiological-statistical methods widen the possibility of preventing the adverse health effects of contaminants. It also shows that correlating geographical and health data has allowed the identification of high risk areas, leading to proactive public health action. 42 Directing targeted blood lead screening in North Carolina. GIS was used to map both North Carolina ZIP codes and census block groups, with at least 27% of houses built prior to ZIP codes that met the above criteria or contained census block groups that met the above criteria, were listed as ZIP codes where universal blood lead screening would occur and, in other North Carolina ZIP codes, a lead risk assessment questionnaire would be completed to determine if the child required screening. 11 Using GIS in Australia to better select sampling areas for blood-lead screenings in children, based on environmental factors, down to individual house levels. The recommendation is that GIS is suited to developing a costefficient and accurate method of modelling lead exposure risk to children. 88 The communication of child lead poisoning rates in Massachusetts. This internet map has rates of lead poisoning by census block level (Figure 10) and can have county outlines and streets added by the user to give the map some geographic context and assist in the comprehension of the occurrence of health outcomes. 89 Identifying areas of high child poverty to determine which family day care homes continue to receive a high level of meal allowance welfare assistance. This process involved mapping census block groups (the equivalent to the Australian SLA) where at least half of the children 0-12 years of age were at

26 or below the 185% of the income to poverty ratio and subsequently identifying which family day care homes operate in those census blocks. 11 Investigating the association between the number of bars, restaurants and off-premise outlets per population and rates of child physical abuse and neglect in 940 census tracts in California, using a cross-sectional ecological study including spatial regression procedures. The study found that alcohol access in neighbourhood areas is associated with substantiated reports of child physical abuse and neglect. The findings suggest there is a spatial dynamic of neighbourhoods that can result in child maltreatment and underscore the importance of examining the alcohol environment when developing programs to prevent child maltreatment. 90 Figure 10: A dynamic map of the 2000 lead poisoning rate per 1000 children aged 6-72 months in Massachusetts. This map has rates mapped to census block level and can have county outlines and streets added by the user to give the map some geographic context. 89 Map created with Maptitude by Caliper

27 1.7 Health promotion Background The greatest strength of GIS is that its product is a picture. 7 It allows health officials to show quickly, clearly, and convincingly the results of a complex analysis. 5 Many of the applications referred to earlier use GIS to produce maps and ultimately present the results of their study to both people who are not professionals in the relevant field and to professionals in a visually striking way, without burying data in tables. 5, 8, 14, 59 In addition to the presentation of complex data in a comprehensible map format, GIS can contribute much more to health promotion. Applications of spatial information GIS and global positioning systems (GPS) have been used to map activity spaces and preferred intervention sites (for both men and women of three different ethnic origins) for the distribution of targeted health promotion materials about Type-2 diabetes. 14 Determinants of chronic disease, including behaviours, healthy and unhealthy, tend to cluster in populations. 91 Consequently, another application for GIS is looking at distribution of behavioural patterns related to health outcomes. Figure 11 is one of many themes from the Behavioural Risk Factor Surveillance System, a state-based system of health surveys that generate information about health risk behaviours, clinical preventive practices, and health care access and use primarily related to chronic diseases and injury. 92 Figure 11. A Behavioural Risk Factor Surveillance System map illustrating by State the 2002 percentage of respondents who answered yes when asked Do you smoke cigarettes now?