Spatial Association of Racial/Ethnic Disparities between Late-stage Diagnosis and Mortality for Female Breast Cancer: Where to Intervene?

International Journal of Health Geographics, 2011, 10:24 (4 April 2011)

Tian N, Wilson JG, and Zhan FB

“Background: Over the past twenty years, racial/ethnic disparities between late-stage diagnoses and mortality outcomes have widened due to disproportionate medical benefits that different racial/ethnic groups have received. Few studies to date have examined the spatial relationships of racial/ethnic disparities between breast cancer late-stage diagnosis and mortality as well as the impact of socioeconomic status (SES) on these two disparities at finer geographic scales.

Geographic distributions of census tracts with significant racial disparities in late-stage diagnosis and mortality for breast cancer using the RD measure for both African-American (a) and Hispanic women (b).

“Methods: Three methods were implemented to assess the spatial relationship between racial/ethnic disparities of breast cancer late-stage diagnosis and morality. First, this study used rate difference measure to test for racial/ethnic disparities in both late-stage diagnosis and mortality of female breast cancer in Texas during 1995-2005. Second, we used linear and logistic regression models to determine if there was a correlation between these two racial/ethnic disparities at the census tract level. Third, a geographically-weighted regression analysis was performed to evaluate if this correlation occurred after weighting for local neighbors.

“Results: The spatial association of racial disparities was found to be significant between late-stage diagnosis and breast cancer mortality with odds ratios of 33.76 (CI: 23.96-47.57) for African Americans and 30.39 (CI: 22.09-41.82) for Hispanics. After adjusting for a SES cofounder, logistic regression models revealed a reduced, although still highly significant, odds ratio of 18.39 (CI: 12.79-26.44) for African-American women and 11.64 (CI: 8.29-16.34) for Hispanic women. Results of the logistic regression analysis indicated that census tracts with low and middle SES were more likely to show significant racial disparities of breast cancer late-stage diagnosis and mortality rates. However, values of local correlation coefficients suggested that the association of these two types of racial/ethnic disparities varied across geographic regions.

“Conclusions: This study may have health-policy implications that can help early detection of breast cancer among disadvantaged minority groups through implementing effective intervention programs in targeted regions.”

Land Use Regression Modeling to Estimate Historic (1962−1991) Concentrations of Black Smoke and Sulfur Dioxide for Great Britain

Environmental Science and Technology, March 29, 2011

John Gulliver, Chloe Morris, Kayoung Lee, Danielle Vienneau, David Briggs, and Anna Hansell

“Land-use regression modeling was used to develop maps of annual average black smoke (BS) and sulfur dioxide (SO2) concentrations in 1962, 1971, 1981, and 1991 for Great Britain on a 1 km grid for use in epidemiological studies. Models were developed in a GIS using data on land cover, the road network, and population, summarized within circular buffers around air pollution monitoring sites, together with altitude and coordinates of monitoring sites to consider global trend surfaces.

“Models were developed against the log-normal (LN) concentration, yielding R2 values of 0.68 (n = 534), 0.68 (n = 767), 0.41 (n = 771), and 0.39 (n = 155) for BS and 0.61 (n = 482), 0.65 (n = 733), 0.38 (n = 756), and 0.24 (n = 153) for SO2 in 1962, 1971, 1981, and 1991, respectively. Model evaluation was undertaken using concentrations at an independent set of monitoring sites. For BS, values of R2 were 0.56 (n = 133), 0.41 (n = 191), 0.38 (n = 193), and 0.34 (n = 37), and for SO2 values of R2 were 0.71 (n = 121), 0.57 (n = 183), 0.26 (n = 189), and 0.31 (n = 38) for 1962, 1971, 1981, and 1991, respectively. Models slightly underpredicted (fractional bias: 0−0.1) monitored concentrations of both pollutants for all years. This is the first study to produce historic concentration maps at a national level going back to the 1960s.”

Spatio-Temporal Analysis Using Urban-Rural Gradient Modelling and Landscape Metrics

Computational Science and Its Applications (ICCSA 2011): Lecture Notes in Computer Science, 2011, Volume 6782/2011, 103-118

Marco Vizzari

“Urbanization can be considered as a particular environmental gradient that produces modifications in the structures and functions of ecological systems. In landscape analysis and planning there is a clear need to develop specific and comparable indicators permitting the spatio-temporal quantification of this gradient and the study of its relationships with the composition and configuration of other land uses. This study, integrating urban gradient modelling and landscape pattern analysis, aims to investigate the spatiotemporal changes induced by urbanization and by other anthropogenic factors.

“Unlike previous studies, based on the transect approach, landscape metrics are calculated diachronically within five contiguous zones defined along the urban to rural gradient and characterized by decreasing intervals of settlement density. The results show that, within the study area, urban sprawl and agricultural land simplification remain the dominant forces responsible for the landscape modifications that have occurred during the period under investigation.”