Using spatially adaptive floating catchments to measure the geographic availability of a health care service: Pulmonary rehabilitation in the southeastern United States

Road network disruptions during extreme flooding events and their impact on the access to emergency medical services: A spatiotemporal vulnerability analysis

The impact of extreme floods can be significant, affecting humans, the environment and any type of human-built infrastructure. A further consequence of flooding is restricted access to medical facilities, including constraints to access more dedicated emergency medical services (EMS). To date, there has been a lack of investigation into EMS accessibility dynamics during extreme floods. The objective of this study is to gain a deeper understanding of the spatiotemporal changes in accessibility-based vulnerability related to EMS during a representative extreme flood event, which was simulated over a period of six days. The study assesses the spatial accessibility of EMS centres to populations located within 15-, 30-, 45-, and 60-minute travel time thresholds in Canton Bern, Switzerland, and applies floating catchment area method. The dynamic aspects of EMS access vulnerability during extreme floods were assessed in two different ways. Firstly, the ratios between accessibility change and accessibility under normal conditions in 1 km grid cells were calculated at hourly moments, t. Subsequently, the resulting values were used to calculate the average vulnerability score. Secondly, percentage changes of affected populations were evaluated for different accessibility classes during the flood event and under all-time high static flood conditions. Varied spatial patterns of accessibility were generally observed with respect to the road network and population distributions in the hilly and mountainous landscape. Extending evaluations to consider temporal dynamics revealed a complex pattern of accessibility gains and losses in different regions of the study area, including those where no direct flood impacts occurred on the road network. The application of a static, all-time high flood condition resulted in an overestimation of accessibility limits to EMS centres. While this overestimation was not considered to be critical, the application of a spatiotemporal accessibility-based vulnerability analysis method to EMS is considered to be more holistic. Insights from this study can be used to evaluate the effectiveness of EMS risk management plans with respect to evolving extreme flood scenarios.

County-Level Cardiac Rehabilitation and Broadband Availability: Opportunities for Hybrid Care in the United States

PURPOSE

Cardiac rehabilitation (CR) improves patient outcomes and quality of life and can be provided virtually through hybrid CR. However, little is known about CR availability in conjunction with broadband access, a requirement for hybrid CR. This study examined the intersection of CR and broadband availability at the county level, nationwide.

METHODS

Data were gathered and analyzed in 2022 from the 2019 American Community Survey, the Centers for Medicare & Medicaid Services, and the Federal Communications Commission. Spatially adaptive floating catchments were used to calculate county-level percent CR availability among Medicare fee-for-service beneficiaries. Counties were categorized: by CR availability, whether lowest (ie, CR deserts), medium, or highest; and by broadband availability, whether CR deserts with majority-available broadband, or dual deserts. Results were stratified by state. County-level characteristics were examined for statistical significance by CR availability category.

RESULTS

Almost half of US adults (n = 116 325 976, 47.2%) lived in CR desert counties (1691 counties). Among adults in CR desert counties, 96.8% were in CR deserts with majority-available broadband (112 626 906). By state, the percentage of the adult population living in CR desert counties ranged from 3.2% (New Hampshire) to 100% (Hawaii and Washington, DC). Statistically significant differences in county CR availability existed by race/ethnicity, education, and income.

CONCLUSIONS

Almost half of US adults live in CR deserts. Given that up to 97% of adults living in CR deserts may have broadband access, implementation of hybrid CR programs that include a telehealth component could expand CR availability to as many as 113 million US adults.

Extending floating catchment area methods to estimate future hospital bed capacity requirements

A new hospital in north-west Sydney, Australia is to start construction in the year 2023. However, the number of emergency department beds/treatment spaces (EDBs) that it will contain is yet to be determined, as this region is expected to have relatively high population growth from year 2021 to year 2036. In this paper, floating catchment area (FCA) methods were employed to estimate the required number of EDBs for this new hospital. Metrics including spatial accessibility index and spatial equity were calculated based on the predicted populations for 2021 and 2036 using government sourced data. Specifically, potential spatial accessibility and horizontal spatial equity were employed for this paper. Mathematical optimisation was used to determine the most efficient distribution of EDBs throughout different hospitals in this region in 2036. The best allocation of capacity across the study area that simultaneously improved average spatial accessibility and improved spatial equity relative to the metrics of 2021 was found. Traditional methods of healthcare planning seldom consider the spatial location of populations or the travel cost to hospitals. This paper presents a novel method to how capacity of future services are determined due to population growth. These results can be compared to traditional methods to access the validity of the methods outlined in this paper.

Examining the impact of COVID-19 vaccination rates on differential access to critical care

The measurement of potential access to health care has focused primarily on what might be called "place-based" access or the differential access among geographic locations rather than between different populations. The vaccination program to inoculate the population against the effects of the COVID-19 virus has created two different at-risk populations. This research examines the impact of COVID-19 vaccination rates on access to critical care for persons fully-vaccinated versus those not fully-vaccinated. In this situation, additional tools are necessary to understand: 1) if there is a significant difference in accessibility between different populations, 2) the magnitude of this difference and how it is distributed across accessibility levels, and 3) how the differences between groups are distributed across the state. A study of access to intensive care unit (ICU) beds by these two populations for the state of Illinois found that although there was a statistically significant difference in access, the magnitude of differences was small. A more important difference was being located in the Chicago Area of the state. The not-fully vaccinated in the Chicago Area had higher than expected spatial access due to the lower need for ICU beds by a higher percentage of fully vaccinated people.

Longitudinal bibliometric analysis applied to home care services

The aim of this study is to present a new methodology to explore a field of research and exercise this technique to find good mathematical models to solve the problem of territorial alignment applied to health services. For this purpose we show a methodology that combines three methods of analysis: social network analysis, longitudinal analysis, and mapping change analysis. In this paper, we applied the mapping change method, originally used in large networks, to small and medium ones, and used the Tabu search scheme instead of simulated annealing. Finally, to highlight the significant changes over time of keywords networks, an alluvial diagram is used to show the significance clusterings through the subperiods studied. The work reports on the most relevant authors on the subject and the most widely used mathematical models applied to solve the problem.

Geographic access to COVID-19 healthcare in Brazil using a balanced float catchment area approach

The rapid spread of COVID-19 across the world has raised concerns about the responsiveness of cities and healthcare systems during pandemics. Recent studies try to model how the number of COVID-19 infections will likely grow and impact the demand for hospitalization services at national and regional levels. However, less attention has been paid to the geographic access to COVID-19 healthcare services and to hospitals' response capacity at the local level, particularly in urban areas in the Global South. This paper shows how transport accessibility analysis can provide actionable information to help improve healthcare coverage and responsiveness. It analyzes accessibility to COVID-19 healthcare at high spatial resolution in the 20 largest cities of Brazil. Using network-distance metrics, we estimate the vulnerable population living in areas with poor access to healthcare facilities that could either screen or hospitalize COVID-19 patients. We then use a new balanced floating catchment area (BFCA) indicator to estimate spatial, income, and racial inequalities in access to hospitals with intensive care unit (ICU) beds and mechanical ventilators while taking into account congestion effects. Based on this analysis, we identify substantial social and spatial inequalities in access to health services during the pandemic. The availability of ICU equipment varies considerably between cities, and it is substantially lower among black and poor communities. The study maps territorial inequalities in healthcare access and reflects on different policy lessons that can be learned for other countries based on the Brazilian case.

Estimating health service utilization potential using the supply-concentric demand-accumulation spatial availability index: a pulmonary rehabilitation case study

The potential for a population at a given location to utilize a health service can be estimated using a newly developed measure called the supply-concentric demand accumulation (SCDA) spatial availability index. Spatial availability is the amount of demand at the given location that can be satisfied by the supply of services at a facility, after discounting the intervening demand among other populations that are located nearer to a facility location than the given population location. This differs from spatial accessibility measures which treat absolute distance or travel time as the factor that impedes utilization. The SCDA is illustrated using pulmonary rehabilitation (PR), which is a treatment for people with chronic obstructive pulmonary disease (COPD). The spatial availability of PR was estimated for each Census block group in Georgia using the 1105 residents who utilized one of 45 PR facilities located in or around Georgia. Data was provided by the Centers for Medicare & Medicaid Services. The geographic patterns of the SCDA spatial availability index and the two-step floating catchment area (2SFCA) spatial accessibility index were compared with the observed PR utilization rate using bivariate local indicators of spatial association. The SCDA index was more associated with PR utilization (Morans I = 0.607, P < 0.001) than was the 2SFCA (Morans I = 0.321, P < 0.001). These results suggest that the measures of spatial availability may be a better way to estimate the health care utilization potential than measures of spatial accessibility.

Accessibility to delivery care in Hubei Province, China

Accessibility to delivery care is crucial for improving maternal health, which is an important policy goal to ensure healthy lives and promote well-being in China and worldwide, especially with the change of the family planning policy in China in 2016. This study develops a set of methods to project the population of women of child-bearing age and birth population and assess the accessibility to delivery care services in Hubei Province. The Cohort-Component projection method with various scenarios was applied to project the population of women of children-bearing age in 2030. A Gravity-based Variable Two-Step Floating Catchment Area (GV2SFCA) method is developed, which takes into account the heterogeneous catchment areas and distance decay effects for different regions and various levels of delivery care services. The parameters are calibrated by using medical records with patients' addresses. The traditional Supply-Demand Ratio method is also applied. The results demonstrate an overall decreasing trend of birth population in Hubei in all scenarios, but with significant disparities across regions. In 2016, 28% of districts fail to reach the policy goal with 17 beds per thousand births. In 2030, accessibility to delivery care is projected to increase in 98% of districts, while there are still 22% of districts that fail to reach the policy goal. The accessibility scores are further combined with the densities of birth population to identify shortage areas of delivery care. 7% and 6% of districts are classified as Major Shortage Areas in 2016 and 2030, respectively. The findings shed lights on the distributions and future changes of accessibility to and shortage areas of delivery care in Hubei, which can provide evidence-based recommendations for planning and policymaking. It also provides innovative methods for more accurately assessing accessibility to delivery care.

Geosocial Factors Associated With Adherence to Statin Medications

Background:

Individual patient characteristics, social determinants, and geographic access may be associated with patients engaging in appropriate health behaviors.

Objective:

To assess the relationship between statin adherence, geographic accessibility to pharmacies, and neighborhood sociodemographic characteristics in Michigan.

Methods:

The proportion of days covered (PDC) was calculated from pharmacy claims of a large insurer of adults who had prescriptions for statins between July 2009 and June 2010. A PDC ≥0.80 was defined as adherent. The predictor of interest was a ZIP code tabulation area (ZCTA)-level measure of geographic accessibility to pharmacies, measured using a method that integrates availability and access into a single index. We fit unadjusted models as well as adjusted models controlling for age, sex, and ZCTA-level measures of socioeconomic status (SES), racial isolation (RI) of non-Hispanic blacks, and urbanicity.

Results:

More than 174 000 patients’ claims data were analyzed. In adjusted models, pharmacy access was not associated with adherence (0.99; 95% CI: 0.96, 1.03). Greater RI (0.87; 95% CI: 0.85, 0.88) and urban status (0.93; 95% CI: 0.89, 0.96) were associated with lower odds of adherence. Individuals in ZCTAs with higher SES had higher odds of adherence, as were men and older age groups.

Conclusion and Relevance:

Adherence to statin prescriptions was lower for patients living in areas characterized as being racially segregated or lower income. Initiating interventions to enhance adherence, informed by understanding the social and systematic barriers patients face when refilling medication, is an important public health initiative that pharmacists practicing in these areas may undertake.

The Impact of Neighborhood Economic and Racial Inequalities on the Spatial Variation of Breast Cancer Survival in New Jersey

BACKGROUND

Mapping breast cancer survival can help cancer control programs prioritize efforts with limited resources. We used Bayesian spatial models to identify whether breast cancer survival among patients in New Jersey (NJ) varies spatially after adjusting for key individual (age, stage at diagnosis, molecular subtype, race/ethnicity, marital status, and insurance) and neighborhood measures of poverty and economic inequality [index of concentration at the extremes (ICE)].

METHODS

Survival time was calculated for all NJ women diagnosed with invasive breast cancer between 2010 and 2014 and followed to December 31, 2015 (N = 27,078). Nonlinear geoadditive Bayesian models were used to estimate spatial variation in hazard rates and identify geographic areas of higher risk of death from breast cancer.

RESULTS

Significant geographic differences in breast cancer survival were found in NJ. The geographic variation of hazard rates statewide ranged from 0.71 to 1.42 after adjustment for age and stage, and were attenuated after adjustment for additional individual-level factors (0.87-1.15) and neighborhood measures, including poverty (0.9-1.11) and ICE (0.92-1.09). Neighborhood measures were independently associated with breast cancer survival, but we detected slightly stronger associations between breast cancer survival, and the ICE compared to poverty.

CONCLUSIONS

The spatial models indicated breast cancer survival disparities are a result of combined individual-level and neighborhood socioeconomic factors. More research is needed to understand the moderating pathways in which neighborhood socioeconomic status influences breast cancer survival.

IMPACT

More effective health interventions aimed at improving breast cancer survival could be developed if geographic variation were examined more routinely in the context of neighborhood socioeconomic inequalities in addition to individual characteristics.