A relative spatial access assessment approach for analyzing potential spatial access to colorectal cancer services in Texas

The usefulness of gravity-based spatial access models is limited because of the uncertainty introduced by the range of values of the impedance coefficient. To solve this problem, this paper proposes the concept of spatial access ratio (SPAR) derived from the enhanced 2-step floating catchment area (E2SFCA) method — a recent extension of the gravity model — to assess potential spatial access. First, a sensitivity assessment is conducted to verify the effectiveness of SPAR and its advantages in overcoming the uncertainty problem. Then, the E2SFCA method and the shortest travel time method are employed to measure potential spatial access to colorectal cancer (CRC) prevention and treatment services in Texas based on data at the census tract level. The socio-demographic and geographic distributions of potential spatial access to CRC services are also examined. The sensitivity assessment reveals substantial fluctuations in the values of the spatial access index calculated directly by the E2SFCA method under different values of the impedance coefficient. However, the values of SPAR remain stable under different values of the coefficient. A comparative analysis indicates that potential spatial access to primary care physicians (PCPs), CRC screening facilities, and oncologists varied among different racial/ethnic and socioeconomic population groups as well as in different geographic regions in Texas. Non-Hispanic blacks, Asians, and people in affluent areas had a geographical advantage in accessing CRC services than other groups. The urban/rural difference was more obvious and serious than those of different racial/ethnic groups and groups with different socio-economic statuses, as metropolitan residents had more than three times the potential spatial access than isolated rural residents.     

Racial/ethnic,area socioeconomic,and geographic disparities of cervical cancer survival in Texas

A better understanding about the factors associated with cervical cancer survival disparities is an important step in developing more effective cervical cancer intervention strategies. This study investigates cervical cancer survival disparities from three different perspectives based on data from the Texas Cancer Registry from 1995 to 2005. These perspectives are race/ethnicity, area socioeconomic status (SES), and geographic locations. We examined the role of both individual- and contextual-level factors in cervical cancer survival disparities using a multilevel survival analysis. Individual-level factors included race/ethnicity, age at diagnosis, year of diagnosis, tumor grade, stage at diagnosis, and type of treatment received. Contextual-level factors are census-tract-level variables, including demographic characteristics, health insurance expenditure, behavioral factors, extent of urbanization, and spatial access to primary care physicians. This study reveals that African-Americans had a higher mortality risk (HR, 1.19; 95% CI, 1.03–1.38) especially if stage was unknown (HR, 1.72; 95% CI, 1.08–2.75) compared with non-Hispanic whites. Among women diagnosed at regional or distant stage, Hispanics had a survival advantage over their non-Hispanic white counterparts (HR, 0.80; 95% CI, 0.69–0.94). We also identified geographic areas where longer-than-expected or shorter-than-expected cervical cancer survival was statistically significant. Only a small portion of these disparities were explained by individual- and contextual-level factors. This study suggests that Race/Ethnicity, SES, and geography are associated with cervical cancer survival in Texas.     

Late-Stage Breast Cancer Diagnosis and Health Care Access in Illinois∗

The variations of breast cancer mortality rates from place to place reflect both underlying differences in breast cancer prevalence and differences in diagnosis and treatment that affect the risk of death. This article examines the role of access to health care in explaining the variation of late-stage diagnosis of breast cancer. We use cancer registry data for the state of Illinois by zip code to investigate spatial variation in late diagnosis. Geographic information systems and spatial analysis methods are used to create detailed measures of spatial access to health care such as convenience of visiting primary care physicians and travel time from the nearest mammography facility. The effects of spatial access, in combination with the influences of socioeconomic factors, on late-stage breast cancer diagnosis are assessed using statistical methods. The results suggest that for breast cancer, poor geographical access to primary health care significantly increases the risk of late diagnosis for persons living outside the city of Chicago. Disadvantaged population groups including those with low income and racial and ethnic minorities tend to experience high rates of late diagnosis. In Illinois, poor spatial access to primary health care is more strongly associated with late diagnosis than is spatial access to mammography. This suggests the importance of primary care physicians as gatekeepers in early breast cancer detection.     

The Best of Times and the Worst of Times: Structural Adjustment Programs and Uneven Development in Africa: The Case Of Ghana

Since 1983, Ghana has been undergoing World Bank and International Monetary Fund (IMF) sponsored Structural Adjustment Programs (SAPs). The implementation of the SAPs, it is claimed, has arrested Ghana's economy from complete collapse, resulted in consistent growth in GDP averaging 6% over the past decade, reduced inflation levels, created budget surplus, and increased export earnings. Compared to the 1970s, these are the best of times indeed. But while these SAPs-derived improvements in the national economy have been recorded at the macro level, the benefits at the micro level are a matter of considerable debate. This study revisits the issue of socioeconomic and spatial disparities that have characterized Ghana since colonial times, emphasizing the period from 1983 when Ghana's SAPs began. It examines current patterns of socioeconomic disparities with emphasis on the distribution of, and access to, health, education, basic services, and the like. The study focuses on urban-rural as well as interregional disparities in the country.     

The Best of Times and the Worst of Times: Structural Adjustment Programs and Uneven Development in Africa: The Case Of Ghana

Since 1983, Ghana has been undergoing World Bank and International Monetary Fund (IMF) sponsored Structural Adjustment Programs (SAPs). The implementation of the SAPs, it is claimed, has arrested Ghana's economy from complete collapse, resulted in consistent growth in GDP averaging 6% over the past decade, reduced inflation levels, created budget surplus, and increased export earnings. Compared to the 1970s, these are the best of times indeed. But while these SAPs‐derived improvements in the national economy have been recorded at the macro level, the benefits at the micro level are a matter of considerable debate. This study revisits the issue of socioeconomic and spatial disparities that have characterized Ghana since colonial times, emphasizing the period from 1983 when Ghana's SAPs began. It examines current patterns of socioeconomic disparities with emphasis on the distribution of, and access to, health, education, basic services, and the like. The study focuses on urban‐rural as well as interregional disparities in the country.     

Spatial spillover and the socio-ecological determinants of diabetes-related mortality across US counties

The spatial structure of diabetes-related mortality in US counties is evident from previous studies. However, it is not clear if spatial variation in diabetes-related mortality is associated with spatial variation in socioecological factors. We analyze the spatial spillover effect of changes in socioeconomic gradients (education, employment, household income), retail food environments, and access to health care, on diabetes-related mortality rates across the United States. Seven-year aggregates of multiple cause mortality data from the CDC WONDER compressed mortality database were merged with several sources of county-level data to examine mortality clusters, factors associated with the clusters, and spatial spillover effects in 3109 continuous US counties. The results suggest that high diabetes-related mortality cluster counties are located throughout the Southern Plains, Southeastern, and Appalachian regions. Lower socioeconomic status, a high density of fast food restaurants, a lack of access to grocery stores, a high proportion of Blacks, and low physical activity characterize high diabetes-related mortality rates clusters. The impacts from improvements in socioeconomic gradients and the retail food environment in neighboring counties spill over, and reduce the diabetes-related mortality rate in a particular county. This result implies that improvements in socioeconomic status and access to healthy food would significantly reduce diabetes-related mortality rates in contiguous US counties.     

Comparing health status and access to health care in Canada’s largest metropolitan areas

Research has shown persistent inequalities in access to health care between and within sociodemographic groups and geographic areas. Yet much of what we know about geographical disparities in access comes from studies of regional and urban/rural contrasts, or from studies of intra-urban, neighborhood-level variations. We know relatively little about variations in access to primary health care across different urban areas, and whether such variations translate into differences among residents’ health. This study examines how health status and access to primary care vary across five of Canada’s largest cities, paying particular attention to populations that may be particularly vulnerable based on age and income. Across all outcomes, there was a consistently strong relationship with individual socioeconomic status. We show that city of residence is important for access to health care but not for health status. Results are discussed in terms of their relevance for urban health-care policy and delivery, and impacts on health and access to care.     

Equity in the distribution of urban environmental amenities: the case of Washington,D.C.

This study examines equity issues in access to urban environmental amenities using Washington, D.C. as a case study. The amenities that are the focus of this study, urban trees and urban parks, have a range of social and health benefits for city dwellers, and Washington, D.C. is a major city with a large, diverse population and long-standing geographic divisions by race and class. Using spatial regression techniques, the study examines disparities in access to these amenities by race, ethnicity, and socioeconomic status at citywide and sub-city scales. Mixed evidence is found for disparities in access across amenities and across scales. The results emphasize the need for studies of access to urban environmental amenities to pay closer attention to the differences between amenities and to issues of scale.     

An environmental justice assessment of public beach access in Miami,Florida

The scope of empirical environmental justice (EJ) research has expanded beyond hazards exposure to scrutinize social inequities in access to amenities, but no prior study has examined the EJ implications of public beach access. Furthermore, quantitative research on white privilege is very scarce. To address these knowledge gaps, our study examines racial/ethnic and socioeconomic inequities in access to public beaches in the Miami metropolitan statistical area, Florida. Public beach accessibility is modeled with an innovative geospatial approach that involves population weighted distances to beach access sites. To assess EJ implications of public beach access for various racial/ethnic and socioeconomically vulnerable groups, spatial regression models are estimated using census tract-level data. Results indicate that beaches are more accessible to neighborhoods with a higher proportion of non-Hispanic Whites, while neighborhoods with higher percentages of Hispanics and socioeconomically disadvantaged residents have limited access. This study demonstrates the importance of assessing white privilege and access to environmental amenities in EJ research to better understand social inequities.     

A three-step floating catchment area method for analyzing spatial access to health services

Gravity-based spatial access models have been widely used to estimate spatial access to healthcare services in an attempt to capture the interaction of various factors. However, these models are inadequate in informing health resource allocation work due to their inappropriate assumption of healthcare demand. For the purpose of effective healthcare resource planning, this article proposes a three-step floating catchment area (3SFCA) method to minimize the healthcare-demand overestimation problem. Specifically, a spatial impedance-based competition scheme is incorporated into the enhanced two-step floating catchment area (E2SFCA) method to account for a reasonable model of healthcare supply and demand. A case study of spatial access to primary care physicians along the Austin–San Antonio corridor area in central Texas showed that the proposed method effectively minimizes the overestimation of healthcare demand and reflects a more balanced geographic pattern of spatial access than E2SFCA. In addition, by using an adjusted spatial access index, the 3SFCA method indicates strong potential for identifying health professional shortage areas. The study concludes that 3SFCA is a promising method to provide health professionals and decision makers with useful healthcare accessibility information.     

Measuring Space–Time Access to Food Retailers: A Case of Temporal Access Disparity in Franklin County,Ohio

Typical measures of food access use spatial-only methods to identify nearby food outlets and the quantity, quality, and variety of food available. This measure of spatial access falls short in explaining the effect that the operating hours of food retailers have on food access. Our study aims to complement the spatial dimension of access measures by bringing time in as a new constraint on food access. To this end, we developed three measures of spatial, temporal, and spatiotemporal access and correlated these measures with socioeconomic status (SES) in a case in Columbus, Ohio. Findings from our analysis of food access disparity suggest that low-SES neighborhoods in Columbus are not at a disadvantage of spatial access, but their limited temporal access is a more pressing concern. Implications drawn from the study would assist community advocates, local governments, and other stakeholders in deriving a better understanding of the local foodscape that are not only mediated by space but also time.     

The relationship between obesity and socioeconomic status among Texas school children and its spatial variation

Understanding the relationships between obesity and socioeconomic status (SES) among school children and the spatial variation of such relationship is essential for developing appropriate intervention strategies. In this study, we employed Local Entropy Map (LEM) to explore the spatial patterns of the relationship at school district level in Texas. Children's obesity was measured by Body Mass Index (BMI). The BMI data for this study were obtained from Physical Fitness Assessment Initiative (PFAI) program that has been coordinated by Texas Education Agency (TEA). SES was described by six variables, which were further reduced into two factors, namely Household SES and Neighborhood SES. The study period was 2012–2013 academic year. LEM analyses revealed clear spatial variation of the relationship between obesity and SES at school-district level. In particular, the prevalence of obesity among school children was found to be significantly related to Household SES and Neighborhood SES in four regions in Texas. These four regions are centered in major metropolitan areas in Texas, including San Antonio, Dallas-Fort Worth, Houston, and Lubbock. Further regression analyses showed variation of the relationship across these four regions. Obesity among school children in Texas was found to be more related to Household SES than Neighborhood SES; the relationship was strongest in San Antonio region. These findings may suggest the presence of obesogenic environment in the low SES school districts in these regions. Further studies to examine the particular nature of the obesogenic environment in these school districts are needed in order to support the development of regionalized policy and practice that can be more effective in addressing locale specifics.     

The role of socio-economic status and spatial effects on fresh food access: Two case studies in Canada

This article comprehensively explores the effects of socio-economic status on residents' fresh food access in Saskatoon and Regina, Saskatchewan, Canada. Spatial effects potentially resulting from agglomeration of food retailers and clustering of neighborhoods with similar characteristics have been integrated into analysis using spatial regression models. Key findings include: areas with a larger percentage of population density, single-parent households, senior populations, higher educational populations, and minority groups tend to have higher access to supermarkets and local grocery stores, although the effects vary by city. Areas with higher private car access are more inclined to be farther from these food retailers, meanwhile the influence of public transportation is found to be insignificant in both cities. Regression results demonstrate that ignoring spatial interaction leads to overestimates of the true disparities when investigating food-access inequality among residents with different socio-economic status.     

Environmental and socioeconomic dynamics of the Indian Ocean tsunami in Penang,Malaysia

This paper addresses some of the environmental and socioeconomic dimensions of the 2004 Indian Ocean tsunami on Penang, Malaysia. We aim to offer wide access to unique and perishable data, while at the same time providing insight to ongoing debates about hazards, vulnerability and social capital. Our social survey examines some of the dynamics that shaped the tsunami impact, response and recovery process. While in terms of lives lost Penang may not conform to arguments surrounding vulnerable environments, the recovery process is more marked by social disparities in terms of the ability to access resources. Our physical survey records local topography, flow depth and flow direction, and charts the differential impact of the tsunami. Yet measuring hazards is not a straightforward process, and relies on reflexive methodologies and eyewitness accounts.     

Household Water Insecurity in the Global North: A Study of Rural and Periurban Settlements on the Texas–Mexico Border

This article examines household-level characteristics that predict water insecurity in low-income rural and periurban communities on the Texas–Mexico border. We employ two logistic regression models (binary and ordered) to identify household characteristics that are more likely to result in water insecurity. Our analyses yielded unexpected findings: Whereas socioeconomic factors are weak predictors, immigration status of household members is a significant variable that contributes to household water insecurity. Policymakers need to pay more attention to marginalized communities as “universal” water access still leaves populations without adequate, reliable, and affordable water in the Global North.     

Does Better Spatial Access Lead to Better Use of Prenatal Care? A Population Study in Georgia

Understanding the effect of spatial accessibility on service utilization is essential to facilitate prenatal care delivery. Previous studies suggest that mothers with better spatial access are more likely to receive adequate prenatal care. Their conclusions, however, are limited by use of small samples and inappropriate spatial accessibility measurements. This article examines the role of spatial accessibility in explaining the variation of prenatal care utilization among 202,377 mothers in Georgia from 2009 to 2011. Specifically, we use geographic information systems and spatial analysis methods to explore the spatial pattern of inadequate prenatal care utilization. A two-transportation-mode, two-step floating catchment area method is used to measure the spatial access to prenatal care by census tract. The effects of spatial accessibility, combined with the influences of demographic, socioeconomic, behavioral, and medical factors, on the adequacy of prenatal care utilization are investigated with statistical models at the individual level. The results show that mothers with better spatial access are less likely to have adequate prenatal care. The inconsistency of this finding with other existing evidence suggests that the effects of spatial accessibility on health service utilization could be complicated and context specific.     

Comparing Measures of Accessibility to Urban Supermarkets for Transit and Auto Users

Research on access to healthy foods often emphasizes the spatial proximity of residents to food stores like supermarkets as a way to gauge overall accessibility. Much of the literature has focused on locating the closest facility, assuming that access to one food store is sufficient. Given evidence that access to multiple healthy food stores can improve diets, however, this article examines how closest facility measures differ from cumulative opportunity accessibility measures across space in a medium-sized U.S. city. Differences in access between automobile and transit riders, using realistic travel time costs, are also considered. Results demonstrate that the two types of accessibility measures produce different accessibility geographies and that there are disparities in access for those dependent on transit. These findings indicate that researchers should carefully consider whether access to one supermarket opportunity is enough and pay special attention to the mode residents rely on to access food.     

Exploring urban commuting imbalance by jobs and gender

Previous findings support that distance matters for job access. Typically, long distances act negatively on job access either due to the lack of information about the opportunities or the cost (time, transportation, etc.). Disparities in job access are explained with the workers’ demographic and socioeconomic characteristics and their spatial condition. Nevertheless, job access was not fully explored in multi-dimensional ways because of data and computational limitations. Recently, the wealth of commuting data, combined with the growing capacity of computation and methodological development, enables us to examine more commuting pattern details than what existing data provide at an aggregate level. This study uses a disaggregate journey-to-work model on 2000 Census Transportation Planning Package (CTPP) commuting data to investigate access to job by gender and occupation, in a more localized context. To explore this varying degree of job access and associated explanation, we analyzed disaggregate commuting flows and ran a regression model on them. This study has three main objectives: (1) to disaggregate journey-to-work flows by gender and occupation to estimate the number of commute trips between census tracts, (2) to explore the variations in job access by gender and occupation, and (3) to draw relationships between job access and various worker’s situations. The results show the details of commuting patterns, suggesting that some occupations have more gender imbalance than others. Further, the findings indicate that the same demographic, socioeconomic and spatial conditions have different effects on workers, and the effect is related to the workers’ demographic-socioeconomic status in complex ways. Unlike conventional research in which a particular worker group is compared to a control group of opposite characteristics, our methodology makes it possible to examine an overview of all the job and gender groups, providing advantages in 2-way comparisons between gender and occupation groups beyond a conventional comparison between two groups. Therefore, our study adds an additional dimension to the conventional comparison.     

Classifying high-prevalence neighborhoods for cardiovascular disease in Texas

Cardiovascular disease (CVD) is the number one cause of death in the state of Texas. In order to develop effective healthcare policies to combat CVD, it is essential to understand what types of communities are most affected. In this paper, we develop a classification scheme to segment high-prevalence communities based on selected social and demographic characteristics. We find that while many high-prevalence areas reflect traditional relationships between socioeconomic deprivation and poor health outcomes, a subset of more affluent communities in Texas are also affected. This suggests the importance of tailored approaches to prevention that account for this diversity among high-prevalence neighborhoods.     

东北振兴以来吉林省区域经济差异的时空演变研究

基于吉林省2003~2015年间地区生产总值和人均地区生产总值数据,以市域、县域两个尺度单元为研究对象,采用人口加权变异系数、基尼系数、泰尔指数等统计分析方法,对吉林省东北振兴战略实施以来的13 a内,区域经济差异的时空演变进行定量分析,并运用泰尔指数的分解方法,探讨了吉林省区域经济差异的空间格局。结果发现：① 吉林省区域经济总体差异、市域差异、县域差异均呈逐年下降趋势。② 通过差异贡献率显示：县域差异是区域总体差异变化的主导力量,长春市域的内部差异远高于其他市域,但有逐年减小的趋势,长吉两地的二元结构仍然突出,是全省区域经济差异产生的主要来源,主导着全省区域经济差异走向;③ 从2003~2015年来看,全省经济增长速度较快的地区主要还是集中在“三核一带”;④吉林省经济差异主要是由资源禀赋、产业结构、极化效应和政策导向等多种因素综合作用的结果。