Richard Fry

Measuring transit system accessibility using a modified two-step floating catchment technique

Previous research has drawn attention to the importance of measuring accessibility to public transit services for transport planning and decision-making purposes and to the use of GIS to produce accessibility maps. Existing measures have been criticised for their lack of sophistication and reliance on simple operations such as Euclidean buffering. This article introduces an accessibility measure based on enhanced ‘floating catchment’ techniques, which have to date not been applied to measure access to public transport opportunities. We demonstrate that, after essential modifications to reflect the characteristics of transit service provision, this approach captures many detailed aspects of accessibility including proximity, the balance between service supply and demand, cumulative opportunity and temporal availability. We illustrate its application using a case study based in South Wales, integrating publicly available digital transport timetables and information on bus stop locations with geospatial analysis tools to provide a realistic appraisal of bus transit accessibility. Such measures could clearly form the basis of future studies of social exclusion and access to public transport opportunities. We conclude by drawing attention to the potential for including more intelligent demand-side and supply-side modelling inputs and by reiterating the policy importance of developing more accurate evaluations of the current and future state of the public transport network.

Investigating the implications of using alternative GIS-based techniques to measure accessibility to green space

A large body of research has examined relationships between accessibility to green space and a variety of health outcomes with many researchers finding benefits in terms of levels of physical activity and relationships with levels of obesity, mental health, and other health conditions. Such studies often use spatial analytical techniques to examine relationships between distance to such spaces and health data collated at an individual survey respondents home address or, more commonly, derived from area-based census measures summarised at a centroid. Generally, such measures are becoming more sophisticated and have moved on from the use of straightforward Euclidean-based measures to those based on network distance. However, few studies tend to use a combination of approaches or seek to establish the implications of incorporating alternative measures of accessibility on potential relationships. Using a database of green spaces (and associated attributes) and a detailed network dataset for the city of Cardiff, Wales, we examine the sensitivity of findings to the ways in which different metrics are calculated. This is illustrated by examining the variations in association between such metrics and a census-based deprivation index widely used in health studies to measure socioeconomic conditions. Our findings demonstrate that not only will the distances to green spaces vary according to the methodologies adopted but that any study that aims to investigate relationships with attributes of the nearest green space should acknowledge that matches may vary widely according to the techniques used. We conclude by warning against the use of inappropriate methodologies in examining access to green space which may directly influence directions (and levels) of association and hence may limit their relevance in wider geographical contexts.

Web-based GIS Approaches to Enhance Public Participation in Wind Farm Planning

Planning information pertaining to the potential visual impacts of proposed construction developments is particularly important in the case of wind farm planning, given the high levels of concern amongst members of the public regarding the perceived negative visual impacts of wind turbines on the landscape. Previous research has highlighted the shortcomings associated with traditional visualization techniques used to assess these impacts, and also the means by which such information is then disseminated to the wider public during the consultation stages of the wind farm planning process. This research is concerned with examining the potential of Web-based mapping and digital landscape visualization techniques for addressing some of these shortcomings. This article reports the findings of a Web-based survey study designed to evaluate the potential of online GIS-based approaches for improving the effectiveness and dissemination of wind farm visualizations and enhancing public participation in the wind farm planning process. Results from the survey study add to the research literature by demonstrating how innovative Web-based approaches have real potential for augmenting existing methods of information provision and public participation in the planning process. The findings of this study are also potentially transferrable to other landscape planning scenarios.

Quantifying the error associated with alternative GIS-based techniques to measure access to health care services

The aim of this study was to quantify the error associated with different accessibility methods commonly used by public health researchers. Network distances were calculated from each household to the nearest GP our study area in the UK. Household level network distances were assigned as the gold standard and compared to alternate widely used accessibility methods. Four spatial aggregation units, two centroid types and two distance calculation methods represent commonly used accessibility calculation methods. Spearmans rank coefficients were calculated to show the extent which distance measurements were correlated with the gold standard. We assessed the proportion of households that were incorrectly assigned to GP for each method. The distance method, level of spatial aggregation and centroid type were compared between urban and rural regions. Urban distances were less varied from the gold standard, with smaller errors, compared to rural regions. For urban regions, Euclidean distances are significantly related to network distances. Network distances assigned a larger proportion of households to the correct GP compared to Euclidean distances, for both urban and rural morphologies. Our results, stratified by urban and rural populations, explain why contradicting results have been reported in the literature. The results we present are intended to be used aide-memoire by public health researchers using geographical aggregated data in accessibility research.

The WISERD Geoportal: A Tool for the Discovery, Analysis and Visualization of Socio-economic (Meta-) Data for Wales

The Wales Institute of Socio-Economic Research, Data and Methods (WISERD) is an interdisciplinary, cross-institutional academic research group based in Wales, UK. One of the key objectives of WISERD is to develop a spatial framework that enhances a researchers ability to discover socio-economic research data relating to Wales with the aim of encouraging collaborative research and re-use of existing data. This article describes the development of an online geoportal designed to meet this objective. Using free and open-source software (FOSS) components and services, a range of software tools has been developed to capture standards-compliant metadata for a variety of data sources. The geoportal is unique in that, in our review of over 120 geoportals worldwide, we have not previously encountered a geoportal dedicated to supporting quantitative and qualitative social science academic and policy research. A particularly innovative aspect of the geoportal has involved the building of a rich meta-database of government surveys, geo-referenced semantically-tagged qualitative data (generated from primary research), ‘grey’ data (e.g. from transcripts, journal publications, books, PhD theses) and Government administrative data. This article describes the challenges faced during the development of the WISERD Geoportal which can be accessed via http://www.wiserd.ac.uk/geoportal/.

Building a geo-portal for enhancing collaborative socio-economic research in Wales using open-source technology

The Wales Institute of Social and Economic Research, Data and Methods (WISERD) is a major new collaborative socio-economic research programme involving five higher education institutions in Wales. This paper introduces the work of the WISERD data integration team and describes their plans for the development of an online geo-portal. Their aim is to support WISERD researchers by providing a framework for integrating, managing and disseminating quantitative and qualitative socio-economic data in Wales. This paper outlines the goals of this major project, discusses the concept of the WISERD geo-portal and reports on initial investigations into geo-portal development using free and open-source (FOSS) software. The paper concludes with a brief summary of the future work of the WISERD data integration team.

A best practice framework to measure spatial variation in alcohol availability

Alcohol outlet density and alcohol-related harms are an internationally reported phenomenon. There are multiple methods described in the literature to measure alcohol outlet density, but with very little commentary on the geographical underpinnings of the methods. In this paper, we present a framework to help practitioners and researchers choose the most appropriate spatial method of measuring alcohol outlet density. The framework includes components on theoretical geography, statistical implications and practical considerations, with an emphasis on population-level exposure. We describe the CHALICE alcohol outlet density measurement method that was developed to investigate the relationships between alcohol outlet density and population harm. The CHALICE method is compared to four other methods found in the published literature. We demonstrate the impact of methodological choices (e.g. network vs. Euclidean distances) on resulting alcohol outlet density scores. We conclude that wherever possible the best practice approach to modelling alcohol outlet density should be used to facilitate flexibility in subsequent statistical analysis and improve the transparency of the results.

Association between alcohol outlet density and alcohol-related mortality in Wales: an e-cohort study

Abstract Background Little is known about the association between alcohol outlet density (AOD) and mortality, and there is a lack of UK longitudinal studies. Results of our previous study on change in AOD and alcohol-related harm to population health (CHALICE) showed that higher availability of alcohol was related to alcohol-related hospital admission. This study aimed to extend this work to investigate the association between AOD and alcohol-related mortality while taking account of migration. Methods Data for the entire population of Wales with a general practice registration on Jan 1, 2006, (n=3 136 881) and follow-up for 24 quarters were record linked using individual identifiers to Office for National Statistics (ONS) mortality files within the Secure Anonymised Information Linkage databank. The Welsh Demographic Service dataset provided information on age, sex, and the lower super output areas (LSOAs) of residence at each of the 24 quarters. To each LSOA at each quarter we linked deprivation fifths using the Welsh Index of Multiple Deprivation 2008 and Rural Urban class as defined by the ONS. AOD was estimated using a mean weighted network distance of all residences to all outlets within a 10 min walk for each LSOA and linked to the dataset by LSOA. Alcohol-related deaths were identified according to the ONS definition. Cox regression models were used to estimate the hazard ratios for mortality associated with quintiles of AOD, adjusting for age, deprivation fifth, and Rural Urban class as time-varying covariates. Migration was accounted for by allowing AOD, deprivation fifth, and Rural Urban class to vary with LSOA moves at every quarter. Findings Of the 2224 alcohol-related deaths 634 (29%) were in areas of the highest AOD quintile. People living in areas of highest AOD had a higher risk of alcohol-related death than those in the lowest AOD quintile (hazard ratio 1·61, 95% CI 1·37–1·89; p Interpretation Increased alcohol availability was associated with a higher risk of alcohol-related death, adjusted for age, sex, and other factors. Although we have included change of outlet density for individuals through quarterly migration between areas, future work should include the change in outlet density in each area over time. Funding Part funded by the National Centre for Population Health and Wellbeing Research and the National Institute for Health Research Public Health Research Programme. The funders had no role in the writing of the abstract or the decision to submit it for publication.

68 Implementation of the ‘School Travel Safety Survey’ for Data Linkage Research

Background The School Travel and Child Safety Survey (STCSS) was developed as part of the European TACTICS project (Tools to Address Childhood Trauma, Injury and Children’s Safety) to address the lack of standardised data on children’s safety and exposure to risk across Europe. Description of the Problem Current methods used to collect data on child safety and exposures to risk are not collected in a coordinated way, making research and policy evaluation in these areas difficult. The STCSS was developed with European partners, as a standardised tool which could be adopted by member states, to collect child safety data and enable comparisons between different regions/countries for policy development and evaluation. Travel behaviour data (e.g. mode of transport and distance travelled) is also limited; but vitally important for monitoring active travel and road safety interventions. Results The STCSS was developed for children aged 10–13 years to be undertaken in school, and was successfully piloted in 5 countries across Europe (n = 636, participation rate = 88.37%). A sample of children were retested to establish the survey reliability, and per cent agreements were ≥96%. The STCSS has been further developed in Wales, to enable the results to be anonymised and incorporated into the Secure Anonymised Information Linkage (SAIL) databank at Swansea University. Data linkage methods within SAIL allow the STCSS results to be linked to other individual and household level datasets; for example, socioeconomic, demographic, health and education data. Conclusions The ability to link the results from this survey to other routinely collected data in the SAIL database, will provide much needed evidence on the medium and long-term effectiveness of child safety interventions and policies; as well as provide regional, national and international policy makers with data to support the planning and evaluation of interventions.

Alcohol outlet density and hospital admissions for alcohol-related injury: an electronic record-linked cohort study

Background Little is known on the longitudinal relationship between alcohol availability and the risk of admission to hospital for an alcohol-related injury. We aimed to quantify this relationship using observational record-linked data in a total adult population cohort in Wales, UK; population 2.5 million aged 16 years and over. Methods Data sources included licensed outlets held by the 22 local authorities in Wales under The Licensing Act 2003 for each quarter between 2006 and 2011. Alcohol outlet density was estimated for Census geography small areas (n = 1896 divided into quintiles of equal counts) based on the mean network walking distances between each household and alcohol outlet within a 10 minute walk. Hospital admissions 2006–2011 from the Patient Episode Database for Wales (PEDW) for wholly alcohol-related conditions were anonymously record-linked to the Welsh Demographic Service age-sex register within the Secure Anonymised Information Linkage Databank. Injury admissions were defined by ICD-10 codes S00-99 and T00-19 linked to an alcohol code. Longitudinal statistical analysis used Cox regression models of hospital admissions as a function of outlet density at baseline, adjusting for confounding variables of age, sex and small area deprivation and settlement type, and censoring for death, migration and other cause admission. Results Alcohol outlet density at baseline was significantly associated with emergency hospital admission; the hazard ratio (HR) of an alcohol-related admission (n = 25,722) for living in the highest compared with the lowest quintile of outlet density was 1.17 (95% CI: 1.11, 1.23). The risk was higher for alcohol-related admissions with injury (n = 4,308; HR 1.27, 95% CI: 1.13, 1.42). Conclusions Higher alcohol outlet availability was associated with more emergency hospital admissions for alcohol-related injury. This suggests that restricting the density of alcohol outlets within walking distance from home may improve population health.