Matthew D. Dunbar

Measures of Human Mobility Using Mobile Phone Records Enhanced with GIS Data

In the past decade, large scale mobile phone data have become available for the study of human movement patterns. These data hold an immense promise for understanding human behavior on a vast scale, and with a precision and accuracy never before possible with censuses, surveys or other existing data collection techniques. There is already a significant body of literature that has made key inroads into understanding human mobility using this exciting new data source, and there have been several different measures of mobility used. However, existing mobile phone based mobility measures are inconsistent, inaccurate, and confounded with social characteristics of local context. New measures would best be developed immediately as they will influence future studies of mobility using mobile phone data. In this article, we do exactly this. We discuss problems with existing mobile phone based measures of mobility and describe new methods for measuring mobility that address these concerns. Our measures of mobility, which incorporate both mobile phone records and detailed GIS data, are designed to address the spatial nature of human mobility, to remain independent of social characteristics of context, and to be comparable across geographic regions and time. We also contribute a discussion of the variety of uses for these new measures in developing a better understanding of how human mobility influences micro-level human behaviors and well-being, and macro-level social organization and change.

Targeted health department expenditures benefit birth outcomes at the county level

BACKGROUND Public health leaders lack evidence for making decisions about the optimal allocation of resources across local health department (LHD) services, even as limited funding has forced cuts to public health services while local needs grow. A lack of data has also limited examination of the outcomes of targeted LHD investments in specific service areas. PURPOSE This study used unique, detailed LHD expenditure data gathered from state health departments to examine the influence of maternal and child health (MCH) service investments by LHDs on health outcomes. METHODS A multivariate panel time-series design was used in 2013 to estimate ecologic relationships between 2000-2010 LHD expenditures on MCH and county-level rates of low birth weight and infant mortality. The unit of analysis was 102 LHD jurisdictions in Washington and Florida. RESULTS Results indicate that LHD expenditures on MCH services have a beneficial relationship with county-level low birth weight rates, particularly in counties with high concentrations of poverty. This relationship is stronger for more targeted expenditure categories, with expenditures in each of the three specific examined MCH service areas demonstrating the strongest effects. CONCLUSIONS Findings indicate that specific LHD investments in MCH have an important effect on related health outcomes for populations in poverty and likely help reduce the costly burden of poor birth outcomes for families and communities. These findings underscore the importance of monitoring the impact of these evolving investments and ensuring that targeted, beneficial investments are not lost but expanded upon across care delivery systems.

Cartographic Symbols for Humanitarian Demining

Abstract A new standard set of cartographic symbols for landmine hazards and mine actions (e.g., clearances, hazard reductions, mine risk education (MRE), and technical surveys) in humanitarian demining activities is proposed, as well as a five-step approach that was utilised to develop the symbol set and that may be applied to the design of related map symbols in digital mapping environments. To promulgate the new symbol set, the Geneva International Centre for Humanitarian Demining and the American Geographical Society recently sponsored workshops in New York, NY, and Reston, VA. Workshop attendees, including key representatives from international organisations, private firms, and NGOs, indicated great enthusiasm for a future global standard.

Assisted partner notification services to augment HIV testing and linkage to care in Kenya: study protocol for a cluster randomized trial

BackgroundHIV case-finding and linkage to care are critical for control of HIV transmission. In Kenya, >50% of seropositive individuals are unaware of their status. Assisted partner notification is a public health strategy that provides HIV testing to individuals with sexual exposure to HIV and are at risk of infection and disease. This parallel, cluster-randomized controlled trial will evaluate the effectiveness, cost-effectiveness, and feasibility of implementing HIV assisted partner notification services at HIV testing sites (clusters) in Kenya.Methods/designEighteen sites were selected among health facilities in Kenya with well-established, high-volume HIV testing programs, to reflect diverse communities and health-care settings. Restricted randomization was used to balance site characteristics between study arms (n = 9 per arm). Sixty individuals testing HIV positive (‘index partners’) will be enrolled per site (inclusion criteria: ≥18 years, positive HIV test at a study site, willing to disclose sexual partners, and never enrolled for HIV care; exclusion criteria: pregnancy or high risk of intimate partner violence). Index partners provide names and contact information for all sexual partners in the past 3 years. At intervention sites, study staff immediately contact sexual partners to notify them of exposure, offer HIV testing, and link to care if HIV seropositive. At control sites, passive partner referral is performed according to national guidelines, and assisted partner notification is delayed by 6 weeks. Primary outcomes, assessed 6 weeks after index partner enrollment and analyzed at the cluster level, are the number of partners accepting HIV testing and number of HIV infections diagnosed and linked to care per index partner. Secondary outcomes are the incremental cost-effectiveness of partner notification and the costs of identifying >1 partner per index case. Participants are closely monitored for adverse outcomes, particularly intimate partner violence. The study is unblinded due to practical limitations.DiscussionThis rigorously designed trial will inform policy decisions regarding implementation of HIV partner notification services in Kenya, with possible application to other parts of sub-Saharan Africa. Examination of effectiveness and cost-effectiveness in diverse settings will enable targeted application and define best practices.Trial registrationClinicalTrials.gov NCT01616420.

A Geography-Specific Approach to Estimating the Distributional Impact of Highway Tolls: An Application to the Puget Sound Region of Washington State

ABSTRACT: This study contributes to the debate about tolls’ equity impacts by examining the potential economic costs of tolling for low-income and non-low-income households. Using data from the Puget Sound metropolitan region in Washington State and geographic information systems methods to map driving routes from home to work, we examine car ownership and transportation patterns among low-income and non-low-income households. We follow standard practice of estimating tolls’ potential impact only on households with workers who would drive on tolled and nontolled facilities. We then redo the analysis including broader groups of households. We find that the degree of regressivity is quite sensitive to the set of households included in the analysis. The results suggest that distributional analyses of tolls should estimate impacts on all households in the relevant region in addition to impacts on just users of roads that are currently tolled or likely to be tolled.

Local Health Department Food Safety and Sanitation Expenditures and Reductions in Enteric Disease, 2000–2010

OBJECTIVES In collaboration with Public Health Practice-Based Research Networks, we investigated relationships between local health department (LHD) food safety and sanitation expenditures and reported enteric disease rates. METHODS We combined annual infection rates for the common notifiable enteric diseases with uniquely detailed, LHD-level food safety and sanitation annual expenditure data obtained from Washington and New York state health departments. We used a multivariate panel time-series design to examine ecologic relationships between 2000-2010 local food safety and sanitation expenditures and enteric diseases. Our study population consisted of 72 LHDs (mostly serving county-level jurisdictions) in Washington and New York. RESULTS While controlling for other factors, we found significant associations between higher LHD food and sanitation spending and a lower incidence of salmonellosis in Washington and a lower incidence of cryptosporidiosis in New York. CONCLUSIONS Local public health expenditures on food and sanitation services are important because of their association with certain health indicators. Our study supports the need for program-specific LHD service-related data to measure the cost, performance, and outcomes of prevention efforts to inform practice and policymaking.

Classifying Local Health Departments on the Basis of the Constellation of Services They Provide

OBJECTIVES We explored service variation among local health departments (LHDs) nationally to allow systematic characterization of LHDs by patterns in the constellation of services they deliver. METHODS We conducted latent class analysis by using categorical variables derived from LHD service data collected in 2008 for the National Profile of Local Health Departments Survey and before service changes resulting from the national financial crisis. RESULTS A 3-class solution produced the best fit for this data set of 2294 LHDs. The 3 configurations of LHD services depicted an interrelated set of narrow or limited service provision (limited), a comprehensive (core) set of key services provided, and a third class of core and expanded services (core plus), which often included rare services. The classes demonstrated high geographic variability and were weakly associated with expenditure quintile and urban or rural location. CONCLUSIONS This empirically derived view of how LHDs organize their array of services is a unique approach to categorizing LHDs, providing an important tool for research and a gauge to monitor how changes in LHD service patterns occur.

Evaluating the Potential of the GeoWall for Geographic Education

Abstract This article discusses modern stereoscopic displays for geographic education, focusing on a large-format display—the GeoWall. To evaluate the potential of the GeoWall, geography instructors were asked to express their reactions to images viewed on the GeoWall during a focus group experiment. Instructors overwhelmingly supported using the GeoWall, stressing the 3-D (three-dimensional) realism provided by stereo images and the excitement these images likely would generate for students. Instructors did, however, note a number of limitations of the GeoWall, including the need to create stereo images (e.g., traditional nonstereo photographs cannot easily be converted to stereo), the need to wear special glasses, and the fact that some people cannot see in stereo. In general, it appeared that the GeoWall would be most useful for complex images and tasks.

Weather-Related Hazards and Population Change: A Study of Hurricanes and Tropical Storms in the United States, 1980–2012

Environmental determinists predict that people move away from places experiencing frequent weather hazards, yet some of these areas have rapidly growing populations. This analysis examines the relationship between weather events and population change in all U.S. counties that experienced hurricanes and tropical storms between 1980 and 2012. Our database allows for more generalizable conclusions by accounting for heterogeneity in current and past hurricane events and losses and past population trends. We find that hurricanes and tropical storms affect future population growth only in counties with growing, high-density populations, which are only 2 percent of all counties. In those counties, current year hurricane events and related losses suppress future population growth, although cumulative hurricane-related losses actually elevate population growth. Low-density counties and counties with stable or declining populations experience no effect of these weather events. Our analysis provides a methodologically informed explanation for contradictory findings in prior studies.

Local Health Department Provision of WIC Services Relative to Local "Need"- Examining 3 States and 5 Years.

Great variation exists in the nature of LHD service delivery and it varies, in part, relative to jurisdiction population size. Larger LHD jurisdictions may achieve an economy of scale in WIC service delivery that is not matched in smaller areas. Overall, we found that WIC service provision appears relatively consistent across study states and in the presence of increasing need, with greater responsiveness to need in urban areas. As demand for some preventive services increases LHDs in rural areas may need greater support than LHDs in large jurisdictions for meeting local demand. Unlike WIC, LHD-provided services that have less consistently maintained service-delivery guidelines may have a harder time responding to increasing need. The relative consistency of a federally-funded program such as WIC may serve as a good baseline for further study of less consistently delivered programs among LHDs. LHD service statistics can serve as useful data sources in measuring volume of service delivery relative to need.