Eugene J. Lengerich

Geovisualization for knowledge construction and decision support

Geovisualization is both a process for leveraging the data resources to meet scientific and societal needs and a research field that develops visual methods and tools to support a wide array of geospatial data applications. While researchers have made substantial advances in geovisualization over the past decade, many challenges remain. To support real-world knowledge construction and decision making, some of the most important challenges involve distributed geovisualization - that is, enabling geovisualization across software components, devices, people, and places.

Geovisual analytics to enhance spatial scan statistic interpretation: an analysis of U.S. cervical cancer mortality

BackgroundKulldorffs spatial scan statistic and its software implementation – SaTScan – are widely used for detecting and evaluating geographic clusters. However, two issues make using the method and interpreting its results non-trivial: (1) the method lacks cartographic support for understanding the clusters in geographic context and (2) results from the method are sensitive to parameter choices related to cluster scaling (abbreviated as scaling parameters), but the system provides no direct support for making these choices. We employ both established and novel geovisual analytics methods to address these issues and to enhance the interpretation of SaTScan results. We demonstrate our geovisual analytics approach in a case study analysis of cervical cancer mortality in the U.S.ResultsWe address the first issue by providing an interactive visual interface to support the interpretation of SaTScan results. Our research to address the second issue prompted a broader discussion about the sensitivity of SaTScan results to parameter choices. Sensitivity has two components: (1) the method can identify clusters that, while being statistically significant, have heterogeneous contents comprised of both high-risk and low-risk locations and (2) the method can identify clusters that are unstable in location and size as the spatial scan scaling parameter is varied. To investigate cluster result stability, we conducted multiple SaTScan runs with systematically selected parameters. The results, when scanning a large spatial dataset (e.g., U.S. data aggregated by county), demonstrate that no single spatial scan scaling value is known to be optimal to identify clusters that exist at different scales; instead, multiple scans that vary the parameters are necessary. We introduce a novel method of measuring and visualizing reliability that facilitates identification of homogeneous clusters that are stable across analysis scales. Finally, we propose a logical approach to proceed through the analysis of SaTScan results.ConclusionThe geovisual analytics approach described in this manuscript facilitates the interpretation of spatial cluster detection methods by providing cartographic representation of SaTScan results and by providing visualization methods and tools that support selection of SaTScan parameters. Our methods distinguish between heterogeneous and homogeneous clusters and assess the stability of clusters across analytic scales.MethodWe analyzed the cervical cancer mortality data for the United States aggregated by county between 2000 and 2004. We ran SaTScan on the dataset fifty times with different parameter choices. Our geovisual analytics approach couples SaTScan with our visual analytic platform, allowing users to interactively explore and compare SaTScan results produced by different parameter choices. The Standardized Mortality Ratio and reliability scores are visualized for all the counties to identify stable, homogeneous clusters. We evaluated our analysis result by comparing it to that produced by other independent techniques including the Empirical Bayes Smoothing and Kafadar spatial smoother methods. The geovisual analytics approach introduced here is developed and implemented in our Java-based Visual Inquiry Toolkit.

Increased incidence of melanoma in renal transplantation recipients.

It is well established that the incidence of nonmelanoma skin carcinoma is increased in renal transplantation recipients. However, existing studies are not in agreement over whether patients who undergo transplantation have an increased risk of melanoma. The objective of this study was to estimate the risk of melanoma among immunosuppressed renal transplantation recipients and to determine whether that risk is associated with patient and transplantation characteristics.

Combining Usability Techniques to Design Geovisualization Tools for Epidemiology

Designing usable geovisualization tools is an emerging problem in GIScience software development. We are often satisfied that a new method provides an innovative window on our data, but functionality alone is insufficient assurance that a tool is applicable to a problem in situ. As extensions of the static methods they evolved from, geovisualization tools are bound to enable new knowledge creation. We have yet to learn how to adapt techniques from interaction designers and usability experts toward our tools in order to maximize this ability. This is especially challenging because there is limited existing guidance for the design of usable geovisualization tools. Their design requires knowledge about the context of work within which they will be used, and should involve user input at all stages, as is the practice in any human-centered design effort. Toward that goal, we have employed a wide range of techniques in the design of ESTAT, an exploratory geovisualization toolkit for epidemiology. These techniques include; verbal protocol analysis, card-sorting, focus groups, and an in-depth case study. This paper reports the design process and evaluation results from our experience with the ESTAT toolkit.

Prostate cancer: demographic and behavioral correlates of stage at diagnosis among blacks and whites in North Carolina☆

OBJECTIVES Although stage at diagnosis is one of the most important predictors of survival from prostate cancer, demographic factors, screening practices, and knowledge and beliefs associated with stage at diagnosis have not been well documented, particularly by race. METHODS We conducted telephone interviews with 117 black and 114 white men diagnosed with prostate cancer to identify the demographic factors, healthcare-seeking behaviors, and prostate cancer-related knowledge, attitudes, and practices associated with stage. The sample was stratified by stage at diagnosis and was composed of men 50 to 74 years old who resided in a contiguous 63-county region in North Carolina and who were diagnosed at 1 of 16 participating hospitals. RESULTS Among blacks, stage was inversely correlated with income (P = 0.04) and health insurance status (P < or = 0.001); among whites, stage was not associated with income or health insurance status, but approached significance with marital status (P = 0.06). Awareness of prostate cancer before diagnosis tended to decline with advancing stage among black men (P = 0.07), but was high for all stages (greater than 93%) among whites. Report of a prostate-specific antigen screen was inversely correlated with stage among black men (P = 0.01); a trend was observed among whites but was not significant (P = 0.20). Knowledge of prostate cancer risk factors was not significantly associated with stage for blacks or whites. Less than one third of men in each race and stage group knew that black men are at increased risk of prostate cancer. CONCLUSIONS Demographic and other factors vary with stage and should be considered when designing and targeting interventions to reduce late diagnosis of prostate cancer.

Treatment options, selection, and satisfaction among african american and white men with prostate carcinoma in north carolina

In the U.S., prostate carcinoma mortality is greatest among African Americans. In North Carolina, the state with the fourth largest population of African Americans, the prostate carcinoma mortality rate is 2.5 times greater among African Americans than among whites and is the highest reported rate for any state in the nation. To explore potential reasons for the racial differential in mortality, a study was undertaken to determine whether differences related to treatment existed between African American and white men who were diagnosed with prostate carcinoma during the period 1994‐1995.

American College of Gastroenterology Guidelines for Colorectal Cancer Screening 2008.

To the Editor: I was disappointed to read the American College of Gastroenterology (ACG) Guidelines for Colorectal Cancer Screening 2008 by Rex et al . (1) . I am concerned that these “ guidelines ” do not even agree with the earlier ACG guidelines nor do they agree with the US Preventive Services Task Force recommendations (2) . What it does agree with are the recommendations of one other gastrointestinal organization: the American Society for Gastrointestinal Endoscopy. I am concerned that these seemingly self-serving recommendations may cause gastroenterology to lose credibility. Th is new ACG recommendation states that colonoscopy is the preferred screening strategy. Unfortunately, there are not enough colonoscopists to keep up with the patients who require colonoscopy, much less those with no risk factors. Other options, such as highly sensitive fecal tests and fl exible sigmoidoscopy, can give broader protection. However, we can all agree that the best screening policy is one that patients will accept.

Breast Cancer Screening, Area Deprivation, and Later-Stage Breast Cancer in Appalachia: Does Geography Matter?

OBJECTIVE To model the relationship of an area-based measure of a breast cancer screening and geographic area deprivation on the incidence of later stage breast cancer (LSBC) across a diverse region of Appalachia. DATA SOURCE Central cancer registry data (2006-2008) from three Appalachian states were linked to Medicare claims and census data. STUDY DESIGN Exploratory spatial analysis preceded the statistical model based on negative binomial regression to model predictors and effect modification by geographic subregions. PRINCIPAL FINDINGS Exploratory spatial analysis revealed geographically varying effects of area deprivation and screening on LSBC. In the negative binomial regression model, predictors of LSBC included receipt of screening, area deprivation, supply of mammography centers, and female population aged>75 years. The most deprived counties had a 3.31 times greater rate of LSBC compared to the least deprived. Effect of screening on LSBC was significantly stronger in northern Appalachia than elsewhere in the study region, found mostly for high-population counties. CONCLUSIONS Breast cancer screening and area deprivation are strongly associated with disparity in LBSC in Appalachia. The presence of geographically varying predictors of later stage tumors in Appalachia suggests the importance of place-based health care access and risk.

Disparities in Underserved White Populations: The Case of Cancer-Related Disparities in Appalachia

There are meaningful cancer-related disparities in the Appalachian region of the U.S. To address these disparities, the Appalachia Community Cancer Network (ACCN), a collaboration of investigators and community partners in five states (Kentucky, Ohio, Pennsylvania, Virginia, and West Virginia), is involved in increasing cancer education and awareness, conducting community-based participatory research (CBPR), and creating mentorship and training opportunities. The primary objective of this paper is to describe cancer-related disparities in the Appalachian region of the U.S. as an example of the disparities experienced by underserved, predominantly white, rural populations, and to describe ACCN activities designed to intervene regarding these disparities. An ACCN overview/history and the diverse activities of ACCN-participating states are presented in an effort to suggest potential useful strategies for working to reduce health-related disparities in underserved white populations. Strengths that have emerged from the ACCN approach (e.g., innovative collaborations, long-standing established networks) and remaining challenges (e.g., difficulties with continually changing communities, scarce resources) are described. Important recommendations that have emerged from the ACCN are also presented, including the value of allowing communities to lead CBPR efforts. Characteristics of the community-based work of the ACCN provide a framework for reducing health-related disparities in Appalachia and in other underserved white and rural populations.

Distributed usability evaluation of the Pennsylvania Cancer Atlas

BackgroundThe Pennsylvania Cancer Atlas (PA-CA) is an interactive online atlas to help policy-makers, program managers, and epidemiologists with tasks related to cancer prevention and control. The PA-CA includes maps, graphs, tables, that are dynamically linked to support data exploration and decision-making with spatio-temporal cancer data. Our Atlas development process follows a user-centered design approach. To assess the usability of the initial versions of the PA-CA, we developed and applied a novel strategy for soliciting user feedback through multiple distributed focus groups and surveys. Our process of acquiring user feedback leverages an online web application (e-Delphi). In this paper we describe the PA-CA, detail how we have adapted e-Delphi web application to support usability and utility evaluation of the PA-CA, and present the results of our evaluation.ResultsWe report results from four sets of users. Each group provided structured individual and group assessments of the PA-CA as well as input on the kinds of users and applications for which it is best suited. Overall reactions to the PA-CA are quite positive. Participants did, however, provide a range of useful suggestions. Key suggestions focused on improving interaction functions, enhancing methods of temporal analysis, addressing data issues, and providing additional data displays and help functions. These suggestions were incorporated in each design and implementation iteration for the PA-CA and used to inform a set of web-atlas design principles.ConclusionFor the Atlas, we find that a design that utilizes linked map, graph, and table views is understandable to and perceived to be useful by the target audience of cancer prevention and control professionals. However, it is clear that considerable variation in experience using maps and graphics exists and for those with less experience, integrated tutorials and help features are needed. In relation to our usability assessment strategy, we find that our distributed, web-based method for soliciting user input is generally effective. Advantages include the ability to gather information from users distributed in time and space and the relative anonymity of the participants while disadvantages include less control over when and how often participants provide input and challenges for obtaining rich input.