Broadband Data Forensics: Spatiotemporal Variations of the Download/Upload Speed Metric Commonly Used to Evaluate Potential Telehealth Accessibility.

Introduction: The complicated task of evaluating potential telehealth access begins with the metrics and supporting datasets that seek toevaluate the presence and durability of broadband connections in a community. Broadband download/upload speeds are one of the popular metrics used to measure potential telehealth access, which is critical to health equity. An understanding of the limitations of these measures is important for drawing conclusions about the reality of the digital divide in telehealth access. The objective of this study was to assess spatiotemporal variations in broadband download/upload speeds. Method: We analyzed a sample of data from the Speedtest Intelligence Portal provided through the Ookla for Good initiative. Results: We found that variation is inherent across the states of Vermont, New Hampshire, Louisiana, and Utah. Conclusions: The variation suggests that when single measures of download/upload speeds are used to evaluate telehealth accessibility they may be masking the true magnitude of the digital divide.

Refining 2SVCA Method for Measuring Telehealth Accessibility of Primary Care Physicians in Baton Rouge, Louisiana.

Equity in health care delivery is a longstanding concern of public health policy. Telehealth is considered an important way to level the playing field by broadening health services access and improving quality of care and health outcomes. This study refines the recently developed "2-Step Virtual Catchment Area (2SVCA) method" to assess the telehealth accessibility of primary care in the Baton Rouge Metropolitan Statistical Area, Louisiana. The result is compared to that of spatial accessibility via physical visits to care providers based on the popular 2-Step Floating Catchment Area (2SFCA) method. The study shows that both spatial and telehealth accessibilities decline from urban to low-density and then rural areas. Moreover, disproportionally higher percentages of African Americans are in areas with higher spatial accessibility scores; but such an advantage is not realized in telehealth accessibility. In the study area, absence of broadband availability is mainly a rural problem and leads to a lower average telehealth accessibility than physical accessibility in rural areas. On the other side, lack of broadband affordability is a challenge across the rural-urban continuum and is disproportionally associated with high concentrations of disadvantaged population groups such as households under the poverty level and Blacks.

Rural-Urban Differences in Breast Cancer Surgical Delays in Medicare Beneficiaries.

BACKGROUND: Delays between breast cancer diagnosis and surgery are associated with worsened survival. Delays are more common in urban-residing patients, although factors specific to surgical delays among rural and urban patients are not well understood. METHODS: We used a 100% sample of fee-for-service Medicare claims during 2007-2014 to identify 238,491 women diagnosed with early-stage breast cancer undergoing initial surgery and assessed whether they experienced biopsy-to-surgery intervals > 90 days. We employed multilevel regression to identify associations between delays and patient, regional, and surgeon characteristics, both in combined analyses and stratified by rurality of patient residence. RESULTS: Delays were more prevalent among urban patients (2.5%) than rural patients (1.9%). Rural patients with medium- or high-volume surgeons had lower odds of delay than patients with low-volume surgeons (odds ratio [OR] = 0.71, 95% confidence interval [CI] = 0.58-0.88; OR = 0.74, 95% CI = 0.61-0.90). Rural patients whose surgeon operated at ≥ 3 hospitals were more likely to experience delays (OR = 1.29, 95% CI = 1.01-1.64, Ref: 1 hospital). Patient driving times ≥ 1 h were associated with delays among urban patients only. Age, black race, Hispanic ethnicity, multimorbidity, and academic/specialty hospital status were associated with delays. CONCLUSIONS: Sociodemographic, geographic, surgeon, and facility factors have distinct associations with > 90-day delays to initial breast cancer surgery. Interventions to improve timeliness of breast cancer surgery may have disparate impacts on vulnerable populations by rural-urban status.

Estimating a Large Travel Time Matrix Between Zip Codes in the United States: A Differential Sampling Approach.

Estimating a massive drive time matrix between locations is a practical but challenging task. The challenges include availability of reliable road network (including traffic) data, programming expertise, and access to high-performance computing resources. This research proposes a method for estimating a nationwide drive time matrix between ZIP code areas in the U.S.-a geographic unit at which many national datasets such as health information are compiled and distributed. The method (1) does not rely on intensive efforts in data preparation or access to advanced computing resources, (2) uses algorithms of varying complexity and computational time to estimate drive times of different trip lengths, and (3) accounts for both interzonal and intrazonal drive times. The core design samples ZIP code pairs with various intensities according to trip lengths and derives the drive times via Google Maps API, and the Google times are then used to adjust and improve some primitive estimates of drive times with low computational costs. The result provides a valuable resource for researchers.

Differential effects of distance decay on hospital inpatient visits among subpopulations in Florida, USA.

Understanding patients' travel behavior for seeking hospital care is fundamental for understanding healthcare market and planning for resource allocation. However, few studies examined the issue comprehensively across populations by geographical, demographic, and health insurance characteristics. Based on the 2011 State Inpatient Database in Florida, this study modeled patients' travel patterns for hospital inpatient care across geographic areas (by average affluence, urbanicity) and calendar seasons, and across subpopulations (by age, gender, race/ethnicity, and health insurance status). Overall, travel patterns for all subpopulations were best captured by the log-logistic function. Patients in more affluent areas and rural areas tended to travel longer for hospital inpatient care, so did the younger, whites, and privately insured. Longer travel distances may be a necessity for rural patients to cope with lack of accessibility for local hospital care, but for the other population groups, it may indicate rather better mobility and more healthcare choices. The results can be used in various healthcare analyses such as accessibility assessment, hospital service area delineation, and healthcare resource planning.

Population-based geographic access to parent and satellite National Cancer Institute Cancer Center Facilities.

BACKGROUND: Satellite facilities of National Cancer Institute (NCI) cancer centers have expanded their regional footprints. This study characterized geographic access to parent and satellite NCI cancer center facilities nationally overall and by sociodemographics. METHODS: Parent and satellite NCI cancer center facilities, which were geocoded in ArcGIS, were ascertained. Travel times from every census tract in the continental United States and Hawaii to the nearest parent and satellite facilities were calculated. Census-based population attributes were used to characterize measures of geographic access for sociodemographic groups. RESULTS: From the 62 NCI cancer centers providing clinical care in 2014, 76 unique parent locations and 211 satellite locations were mapped. The overall proportion of the population within 60 minutes of a facility was 22% for parent facilities and 32.7% for satellite facilities. When satellites were included for potential access, the proportion of some racial groups for which a satellite was the closest NCI cancer center facility increased notably (Native Americans, 22.6% with parent facilities and 39.7% with satellite facilities; whites, 34.8% with parent facilities and 50.3% with satellite facilities; and Asians, 40.0% with parent facilities and 54.0% with satellite facilities), with less marked increases for Hispanic and black populations. Rural populations of all categories had dramatically low proportions living within 60 minutes of an NCI cancer center facility of any type (1.0%-6.6%). Approximately 14% of the population (n = 43,033,310) lived more than 180 minutes from a parent or satellite facility, and most of these individuals were Native Americans and/or rural residents (37% of Native Americans and 41.7% of isolated rural residents). CONCLUSIONS: Racial/ethnic and rural populations showed markedly improved geographic access to NCI cancer center care when satellite facilities were included. Cancer 2017;123:3305-11. © 2017 American Cancer Society.

Disparities in Geographic Accessibility of National Cancer Institute Cancer Centers in the United States.

The National Cancer Institute (NCI) Cancer Centers form the backbone of the cancer care system in the United States since their inception in the early 1970s. Most studies on their geographic accessibility used primitive measures, and did not examine the disparities across urbanicity or demographic groups. This research uses an advanced accessibility method, termed "2-step floating catchment area (2SFCA)" and implemented in Geographic Information Systems (GIS), to capture the degree of geographic access to NCI Cancer Centers by accounting for competition intensity for the services and travel time between residents and the facilities. The results indicate that urban advantage is pronounced as the average accessibility is highest in large central metro areas, declines to large fringe metro, medium metro, small metro, micropolitan and noncore rural areas. Population under the poverty line are disproportionally concentrated in lower accessibility areas. However, on average Non-Hispanic White have the lowest geographic accessibility, followed by Hispanic, Non-Hispanic Black and Asian, and the differences are statistically significant. The "reversed racial disadvantage" in NCI Cancer Center accessibility seems counterintuitive but is consistent with an influential prior study; and it is in contrast to the common observation of co-location of concentration of minority groups and people under the poverty line.

Multilevel built environment features and individual odds of overweight and obesity in Utah.

Based on the data from the Behavioral Risk Factor Surveillance System (BRFSS) in 2007, 2009 and 2011 in Utah, this research uses multilevel modeling (MLM) to examine the associations between neighborhood built environments and individual odds of overweight and obesity after controlling for individual risk factors. The BRFSS data include information on 21,961 individuals geocoded to zip code areas. Individual variables include BMI (body mass index) and socio-demographic attributes such as age, gender, race, marital status, education attainment, employment status, and whether an individual smokes. Neighborhood built environment factors measured at both zip code and county levels include street connectivity, walk score, distance to parks, and food environment. Two additional neighborhood variables, namely the poverty rate and urbanicity, are also included as control variables. MLM results show that at the zip code level, poverty rate and distance to parks are significant and negative covariates of the odds of overweight and obesity; and at the county level, food environment is the sole significant factor with stronger fast food presence linked to higher odds of overweight and obesity. These findings suggest that obesity risk factors lie in multiple neighborhood levels and built environment features need to be defined at a neighborhood size relevant to residents' activity space.

Characterizing the Traveling Oncology Workforce and Its Influence on Patient Travel Burden: A Claims-Based Approach.

PURPOSE: Oncology outreach is a common strategy for extending cancer care to rural patients. However, a nationwide characterization of the traveling workforce that enables this outreach is lacking, and the extent to which outreach reduces travel burden for rural patients is unknown. METHODS: This cross-sectional study analyzed a rural (nonurban) subset of a 100% fee-for-service sample of 355,139 Medicare beneficiaries with incident breast, colorectal, and lung cancers. Surgical, medical, and radiation oncologists were linked to patients using Part B claims, and traveling oncologists were identified by observing hospital service area (HSA) transition patterns. We defined oncology outreach as the provision of cancer care by a traveling oncologist outside of their primary HSA. We used hierarchical gamma regression models to examine the separate associations between patient receipt of oncology outreach and one-way patient travel times to chemotherapy, radiotherapy, and surgery. RESULTS: On average, 9,935 of 39,960 oncologists conducted annual outreach, where 57.8% traveled with low frequency (0-1 outreach visits/mo), 21.1% with medium frequency (1-3 outreach visits/mo), and 21.1% with high frequency (>3 outreach visits/mo). Oncologists provided surgery, radiotherapy, and chemotherapy to 51,715, 27,120, and 5,874 rural beneficiaries, respectively, of whom 2.5%, 6.9%, and 3.6% received oncology outreach. Rural patients who received oncology outreach traveled 16% (95% CI, 11 to 21) and 11% (95% CI, 9 to 13) less minutes to chemotherapy and radiotherapy than those who did not receive oncology outreach, corresponding to expected one-way savings of 15.9 (95% CI, 15.5 to 16.4) and 11.9 (95% CI, 11.7 to 12.2) minutes, respectively. CONCLUSION: Our study introduces a novel claims-based approach for tracking the nationwide traveling oncology workforce and supports oncology outreach as an effective means for improving rural access to cancer care.

Population-Adjusted Street Connectivity, Urbanicity and Risk of Obesity in the U.S.

Street connectivity, defined as the number of (3-way or more) intersections per area unit, is an important index of built environments as a proxy for walkability in a neighborhood. This paper examines its geographic variations across the rural-urban continuum (urbanicity), major racial-ethnic groups and various poverty levels. The population-adjusted street connectivity index is proposed as a better measure than the regular index for a large area such as county due to likely concentration of population in limited space within the large area. Based on the data from the Behavioral Risk Factor Surveillance System (BRFSS), this paper uses multilevel modeling to analyze its association with physical activity and obesity while controlling for various individual and county-level variables. Analysis of data subsets indicates that the influences of individual and county-level variables on obesity risk vary across areas of different urbanization levels. The positive influence of street connectivity on obesity control is limited to the more but not the mostly urbanized areas. This demonstrates the value of obesogenic environment research in different geographic settings, helps us reconcile and synthesize some seemingly contradictory results reported in different studies, and also promotes that effective policies need to be highly sensitive to the diversity of demographic groups and geographically adaptable.

Disparities in spatial accessibility of primary care in Louisiana: From physical to virtual accessibility.

Telehealth has been widely employed and has transformed how healthcare is delivered in the United States as a result of COVID-19 pandemic. While telehealth is utilized and encouraged to reduce the cost and travel burden for access to healthcare, there are debates on whether telehealth can promote equity in healthcare services by narrowing the gap among diverse groups. Using the Two-Step Floating Catchment Area (2SFCA) and Two-Step Virtual Catchment Area (2SVCA) methods, this study compares the disparities of physical and virtual access to primary care physicians (PCPs) in Louisiana. Both physical and virtual access to PCPs exhibit similar spatial patterns with higher scores concentrated in urban areas, followed by low-density and rural areas. However, the two accessibility measures diverge where broadband availability and affordability come to play an important role. Residents in rural areas experience additive disadvantage of even more limited telehealth accessibility than physical accessibility due to lack of broadband service provision. Areas with greater Black population proportions tend to have better physical accessibility, but such an advantage is eradicated for telehealth accessibility because of lower broadband subscription rates in these neighborhoods. Both physical and virtual accessibility scores decline in neighborhoods with higher Area Deprivation Index (ADI) values, and the disparity is further widened for in virtual accessibility compared to than physical accessibility. The study also examines how factors such as urbanicity, Black population proportion, and ADI interact in their effects on disparities of the two accessibility measures.

Numerical and Experimental Study on Flame Dynamics of the Premixed Methane-Air Mixture at Different Ignition Positions in a Two-Side 45° Branch Tube.

The combustion characteristics of premixed methane-air flames in a half-open tube with a two-sided 45° branch structure at different ignition positions were investigated by experiments and large eddy simulations. The numerical results were compared with the experimental results to verify the correctness of the model. The results show that the simulation results are highly consistent with the experiment. This study provides a basic understanding of the effects of the branch tube structure and the ignition position on flame dynamics. When the flame propagates to the branch interface, it forms a symmetrical vortex structure at the branch tube with the opposite rotation direction. When the ignition position is at IP0 and IP900, the maximum overpressures obtained in the experiment are 10.1 and 10.7 kPa, respectively, and 9.2 and 10.4 kPa in the simulation, respectively. At IP0, the Karlovitz number indicating the interaction intensity between the flame surface and the turbulence during flame propagation is a maximum of 9.2 and a minimum of 0.04. The premixed flame has a folded small flame, a corrugated small flame, and a thin reaction zone.

The interaction of rurality and rare cancers for travel time to cancer care.

PURPOSE: Geographic access to cancer care is known to significantly impact utilization and outcomes. Longer travel times have negative impacts for patients requiring highly specialized care, such as for rare cancers, and for those in rural areas. Scant population-based research informs geographic access to care for rare cancers and whether rurality impacts that access. METHODS: Using Medicare data (2014-2015), we identified prevalent cancers and cancer-directed surgeries, chemotherapy, and radiation. We classified cancers as rare (incidence <6/100,000/year) or common (incidence ≥6/100,000/year) using previously published thresholds and categorized rurality from ZIP code of beneficiary residence. We estimated travel time between beneficiaries and providers for each service based on ZIP code. Descriptive statistics summarized travel time by rare versus common cancers, service type, and rurality. FINDINGS: We included 1,169,761 Medicare beneficiaries (21.9% in nonmetropolitan areas), 87,399; 7.5% had rare cancers, with 9,133,003 cancer-directed services. Travel times for cancer services ranged from approximately 29 minutes (25th percentile) to 68 minutes (75th percentile). Travel times were similar for rare and common cancers overall (median: 45 vs 43 minutes) but differed by service type; 13.4% of surgeries were >2 hours away for rare cancers, compared to 8.3% for common cancers. Increasing rurality disproportionately increased travel time to surgical care for rare compared to common cancers. CONCLUSIONS: Travel times to cancer services are longest for surgery, especially among rural residents, yet not markedly longer overall between rare versus common cancers. Understanding geographic access to cancer care for patients with rare cancers is important to delivering specialized care.

GIS-Automated Delineation of Hospital Service Areas in Florida: From Dartmouth Method to Network Community Detection Methods.

Since the Dartmouth hospital service areas (HSAs) were proposed three decades ago, there has been a large body of work using the unit in examining the geographic variation in health care in the U.S. for evaluating health care system performance and informing health policy. However, many studies question the replicability and reliability of the Dartmouth HSAs in meeting the challenges of ever-changing and a diverse set of health care services. This research develops a reproducible, automated, and efficient GIS tool to implement Dartmouth method for defining HSAs. Moreover, the research adapts two popular network community detection methods to account for spatial constraints for defining HSAs that are scale flexible and optimize an important property such as maximum service flows within HSAs. A case study based on the state inpatient database in Florida from the Healthcare Cost and Utilization Project is used to evaluate the efficiency and effectiveness of the methods. The study represents a major step toward developing HSA delineation methods that are computationally efficient, adaptable for various scales (from a local region to as large as a national market), and automated without a steep learning curve for public health professionals.

Delineation of Cancer Service Areas Anchored by Major Cancer Centers in the United States.

Defining a reliable geographic unit pertaining to cancer care is essential in its assessment, planning, and management. This study aims to delineate and characterize the cancer service areas (CSA) accounting for the presence of major cancer centers in the United States. We used the Medicare enrollment and claims from January 1, 2014 to September 30, 2015 to build a spatial network from patients with cancer to cancer care facilities that provided inpatient and outpatient care of cancer-directed surgery, chemotherapy, and radiation. After excluding those without clinical care or outside of the United States, we identified 94 NCI-designated and other academic cancer centers from the members of the Association of American Cancer Institutes. By explicitly incorporating existing specialized cancer referral centers, we refined the spatially constrained Leiden method that accounted for spatial adjacency and other constraints to delineate coherent CSAs within which the service volumes were maximal but minimal between them. The derived 110 CSAs had a high mean localization index (LI; 0.83) with a narrow variability (SD = 0.10). The variation of LI across the CSAs was positively associated with population, median household income, and area size, and negatively with travel time. Averagely, patients traveled less and were more likely to receive cancer care within the CSAs anchored by cancer centers than their counterparts without cancer centers. We concluded that CSAs are effective in capturing the local cancer care markets in the United States. They can be used as reliable units for studying cancer care and informing more evidence-based policy. Significance: Using the most refined network community detection method, we can delineate CSAs in a more robust, systematic, and empirical manner that incorporates existing specialized cancer referral centers. The CSAs can be used as a reliable unit for studying cancer care and informing more evidence-based policy in the United States. The cross-walk tabulation of ZIP code areas, CSAs, and related programs for CSAs delineation are disseminated for public access.

Multiscale analysis of cancer service areas in the United States.

The purpose of delineating Cancer Service Areas (CSAs) is to define a reliable unit of analysis, more meaningful than geopolitical units such as states and counties, for examining geographic variations of the cancer care markets using geographic information systems (GIS). This study aims to provide a multiscale analysis of the U.S. cancer care markets based on the 2014-2015 Medicare claims of cancer-directed surgery, chemotherapy, and radiation. The CSAs are delineated by a scale-flexible network community detection algorithm automated in GIS so that the patient flows are maximized within CSAs and minimized between them. The multiscale CSAs include those comparable in size to those 4 census regions, 9 divisions, 50 states, and also 39 global optimal CSAs that generates the highest modularity value. The CSAs are more effective in capturing the U.S. cancer care markets because of its higher localization index, lower cross-border utilizations, and shorter travel time. The first two comparisons reveal that only a few regions or divisions are representative of the underlying cancer care markets. The last two comparisons find that among the 39 CSAs, 54% CSAs comprise multiple states anchored by cities near inner state borders, 28% are single-state CSAs, and 18% are sub-state CSAs. Their (in)consistencies across state borders or within each state shed new light on where the intervention of cancer care delivery or the adjustment of cancer care costs are needed to meet the challenges in the U.S. cancer care system. The findings could guide stakeholders to target public health policies for more effective coordination of cancer care in improving outcomes and reducing unnecessary costs.

Flame Propagation Characteristics of Syngas-Air in the Hele-Shaw Duct with Different Equivalence Ratios and Ignition Positions.

In this paper, the effects of different ignition positions and equivalence ratios on the explosion characteristics of syngas in a half-open Hele-Shaw duct were investigated. The ignition points are set at distances of 0 and 500 mm from the closed end. Moreover, the research range of equivalence ratio is 0.8-1.2. The experimental results indicate that different ignition positions and equivalence ratios influence the flame front structure and the dynamic characteristics of flame propagation. When the ignition position is at the closed end, the flame front undergoes several typical propagation stages before eventually reaching the open end of the duct. The time required by the flame to reach the open end decreases as the equivalence ratio increases. Meanwhile, when the ignition is in the middle of the duct, the flame simultaneously spreads to the open and closed ends. The time required to reach both sides decreases with the increase in the equivalence ratio. The flame front structure and pressure are primarily affected by the ignition position and the equivalence ratio. At the same ignition position, flame propagation velocity and maximum overpressure increase with the equivalence ratio. The pressure oscillation becomes more intense when the ignition position is close to the open end. At IP500, when the equivalence ratio is 0.8, multiple finger-shaped flame fronts emerge, accompanied by high-frequency flame oscillations. This study can provide guidance for the study of the flame propagation characteristics of syngas in millimeter-scale burners.

The uneven reaction to combat the COVID-19 pandemic: Geovisualizing of fever clinics in mainland China.

The COVID-19 pandemic has exerted unprecedented impacts on the world. Since its onset, China has established a network of fever clinics as an effective strategy to aggressively isolate and screen possible patients with COVID-19 symptoms. This study presents two fever clinic maps that visualize the uneven responses to the COVID-19 pandemic at the city level in mainland China. The maps highlight more resources in the southwest, northwest, east, and south China, and paucity in the far west parts of southwest and northwest China and in the north and northeast China.

Kinetic Analysis of Laminar Combustion Characteristics of a H2/Cl2 Mixture at CO2/N2 Dilution.

Garbage and biomass contain more chlorine, which reacts with H2 to form HCl gas during combustion or gasification, resulting in corrosion of metal walls. In this paper, based on the chlorine mechanism in Ansys Chemkin-Pro, the laminar combustion characteristics of H2/Cl2 are simulated with different diluents CO2/N2 under an initial temperature of 298 K, equivalence ratio range of 0.6-1.4, and initial pressure of 0.1-0.5 MPa. The results show that the laminar burning velocity of H2/Cl2 decreases significantly with the increase of dilution gas ratio, and the effect of diluent CO2 is more significant than that of N2. Due to the dilution effect, the fuel and oxidation components are reduced. Through sensitivity analysis, reaction R2: Cl + H2 = HCl + H is the main reaction of HCl formation. On improving the initial pressure, the laminar burning velocity is slightly lowered, and the thermal diffusivity of the fuel mixture increases with the increase of the initial pressure. According to the sensitivity analysis of the velocity, reactions R2, R9, and R10 are the main reactions that affect the laminar burning velocity, and the product HCl will be generated with a delay with the increase of the initial pressure.

Rural - urban inequalities in late-stage breast cancer: spatial and social dimensions of risk and access.

Rural - urban inequalities in health and access to health care have long been of concern in health-policy formulation. Understanding these inequalities is critically important in efforts to plan a more effective geographical distribution of public health resources and programs. Socially and ethnically diverse populations are likely to exhibit different rural - urban gradients in health and well-being because of their varying experiences of place environments, yet little is known about the interplay between social and spatial inequalities. Using data from the Illinois State Cancer Registry, we investigate rural - urban inequalities in late-stage breast cancer diagnosis both for the overall population and for African-Americans, and the impacts of socioeconomic deprivation and spatial access to health care. Changes over time are analyzed from 1988 - 92 to 1998 - 2002, periods of heightened breast cancer awareness and increased access to screening. In both time periods, the risk of late-stage diagnosis is highest among patients living in the most urbanized areas, an indication of urban disadvantage. Multilevel modeling results indicate that rural - urban inequalities in risk are associated with differences in the demographic characteristics of area populations and differences in the social and spatial characteristics of the places in which they live. For African-American breast cancer patients, the rural - urban gradient is reversed, with higher risks among patients living outside the city of Chicago, suggesting a distinct set of health-related risks and place experiences that inhibit early breast cancer detection. Findings emphasize the need for combining spatial and social targeting in locating cancer prevention and treatment programs.