Optimizing mobile mammography deployment in Oklahoma 2024: a two-step floating catchment area approach.

The issue of reducing spatial disparities in access to healthcare is one of the most important healthcare planning issues that policy makers and planners investigate and consider as a key focus until present time. A healthcare system that meets the requirements of availability and affordability will be useless if the spatial accessibility to healthcare is not provided to all equally. Therefore, this study aims to identify and analyze spatial disparities in access to healthcare centers in Jeddah, Saudi Arabia. The two-step floating catchment area (2SFCA) method was used to measure spatial accessibility of healthcare centers based on the travel time threshold (i.e., 30-min drive time in this study). The GIS technology was used to execute the 2SFCA method. A geodatabase, which includes the population districts, locations of healthcare centers, and road network, was created. Some procedures were performed within the road network database to set the travel time that is considered as an essential step to compute the origin–destination (OD) cost matrix. The OD matrix was later used as the source for calculating provider-to-population ratios and the spatial accessibility scores for population districts. The results of the study revealed spatial disparities in access to healthcare centers in Jeddah city. The majority of the Jeddah population (i.e., 97.51%) have accessibility to healthcare centers, but with disparate levels. The central districts have a higher access score compared to the rest of the city’s districts. Most districts that do not have accessibility to healthcare centers are concentrated in the southeast of the city. The results can help local health planners improve spatial equity in access to healthcare centers through giving the less-served districts a priority when allocating future healthcare centers in Jeddah city.

219: Factors In Recruiting and Retaining Emergency Physicians to Rural Emergency Departments

In Japan, a decline in tuberculosis (TB) notification rates and shortening of duration of hospitalisation have led to a drastic decrease in the number of hospital beds for TB patients (TB beds), causing severe undersupply in certain regions. To assess the current status of spatial access to TB beds in Japan and evaluate the potential impact of health resource reconstruction in mitigating undersupply of TB beds. A cross-sectional study was conducted whereby a two-step floating catchment area (2SFCA) method was used to calculate an 'accessibility score' to evaluate spatial accessibility of TB beds in the regions classified by four levels of urbanisation. The impact of introducing 'potential TB beds' was assessed via the changes in the proportion of undersupplied regions and TB patients notified from undersupplied regions. Undersupplied regions were characterised by 'very low', 'low' and 'moderate' level of urbanisation. By introducing 'potential TB beds', the proportion of both undersupplied regions and TB patients could be significantly reduced, especially in less urbanised regions. Our results may be used to guide future decision-making over resource allocation of TB care in Japan. The 2SFCA method may be applied to other countries using appropriate demand and supply variables.

BackgroundQuantifying spatial access to care—the interplay of accessibility and availability—is vital for healthcare planning and understanding implications of services (mal-)distribution. A plethora of methods aims to measure potential spatial access to healthcare services. The current study conducts a systematic review to identify and assess gravity model-type methods for spatial healthcare access measurement and to summarize the use of these measures in empirical research.MethodsA two-step approach was used to identify (1) methodological studies that presented a novel gravity model for measuring spatial access to healthcare and (2) empirical studies that applied one of these methods in a healthcare context. The review was conducted according to the PRISMA guidelines. EMBASE, CINAHL, Web of Science, and Scopus were searched in the first step. Forward citation search was used in the second step.ResultsWe identified 43 studies presenting a methodological development and 346 empirical application cases of those methods in 309 studies. Two major conceptual developments emerged: The Two-Step Floating Catchment Area (2SFCA) method and the Kernel Density (KD) method. Virtually all other methodological developments evolved from the 2SFCA method, forming the 2SFCA method family. Novel methodologies within the 2SFCA family introduced developments regarding distance decay within the catchment area, variable catchment area sizes, outcome unit, provider competition, local and global distance decay, subgroup-specific access, multiple transportation modes, and time-dependent access. Methodological developments aimed to either approximate reality, fit a specific context, or correct methodology. Empirical studies almost exclusively applied methods from the 2SFCA family while other gravity model types were applied rarely. Distance decay within catchment areas was frequently implemented in application studies, however, the initial 2SFCA method remains common in empirical research. Most empirical studies used the spatial access measure for descriptive purposes. Increasingly, gravity model measures also served as potential explanatory factor for health outcomes.ConclusionsGravity models for measuring potential spatial healthcare access are almost exclusively dominated by the family of 2SFCA methods—both for methodological developments and applications in empirical research. While methodological developments incorporate increasing methodological complexity, research practice largely applies gravity models with straightforward intuition and moderate data and computational requirements.

ABSTRACTThe recent decade has witnessed a new wave of development in the place-based accessibility theory, revolving around the two-step floating catchment area (2SFCA) method. The 2SFCA method, initially serving to evaluate the spatial inequity of health care services, has been further applied to other urban planning and facility access issues. Among these applications, different distance decay functions have been incorporated in the thread of model development, but their applicability and limitations have not been thoroughly examined. To this end, the paper has employed a place-based accessibility framework to compare the performance of twenty-four 2SFCA models in a comprehensive manner. Two important conclusions are drawn from this analysis: on a small analysis scale (e.g., community level), the catchment size is the most critical model component; on a large analysis scale (e.g., statewide), the distance decay function is of elevated importance. In sum, this comparative analysis provides the theoretical support necessary to the choice of the catchment size and the distance decay function in the 2SFCA method. Justification of model parameters through empirical evidence (e.g., field surveys about local travel activities) and model validation through sensitivity analysis are needed in future 2SFCA applications for various urban planning, service delivery, and spatial equity scenarios.

Two-step floating catchment area (2SFCA) methods that account for multiple transportation modes provide more realistic accessibility representation than single-mode methods. However, the use of the impedance coefficient in an impedance function (e.g., Gaussian function) introduces uncertainty to 2SFCA results. This paper proposes an enhancement to the multi-modal 2SFCA methods through incorporating the concept of a spatial access ratio (SPAR) for spatial access measurement. SPAR is the ratio of a given place’s access score to the mean of all access scores in the study area. An empirical study on spatial access to primary care physicians (PCPs) in the city of Albuquerque, NM, USA was conducted to evaluate the effectiveness of SPAR in addressing uncertainty introduced by the choice of the impedance coefficient in the classic Gaussian impedance function. We used ESRI StreetMap Premium and General Transit Specification Feed (GTFS) data to calculate the travel time to PCPs by car and bus. We first generated two spatial access scores—using different catchment sizes for car and bus, respectively—for each demanding population location: an accessibility score for car drivers and an accessibility score for bus riders. We then computed three corresponding spatial access ratios of the above scores for each population location. Sensitivity analysis results suggest that the spatial access scores vary significantly when using different impedance coefficients (p < 0.05); while SPAR remains stable (p = 1). Results from this paper suggest that a spatial access ratio can significantly reduce impedance coefficient-related uncertainties in multi-modal 2SFCA methods.

In order to access the spatial accessibility of emergency shelters, the relationship between the supply and demand of emergency shelters in the two dimensions of space and non-space must be comprehensively considered. Meanwhile, it is vital to understand the competitive relationship among emergency shelters. However, there are disadvantages when using the two-step floating catchment area (2SFCA) method and the improved 2SFCA method when addressing these issues. This study proposes the adaptive catchment size 2SFCA (A-2SFCA) method to calculate spatial accessibility values, which can work alongside the two relationships mentioned above. The analysis procedure of the A-2SFCA method has two stages. Firstly, this method adjusts the catchment size of the shelters by observing how crowded they are and repeatedly using this statistic in a service subset. At the end of this stage, every catchment area is determined. Secondly, the catchment areas are used to calculate the spatial accessibility values. The method was used to study a region in the Tianjin urban area in China. The proposed A-2SFCA and fixed-coverage-based two-step floating catchment area (FC2SFCA) methods are employed to measure and compare the spatial accessibility values. The result shows that the spatial accessibility in Tianjin urban area is unstable. The spatial accessibility result obtained from the A-2SFCA method is more reasonable than the FC2SFCA method when analyzing the reasonable catchment areas of emergency shelters. The A-2SFCA method provides a method for determining the catchment size of public service providers, which can be used for the accessibility analysis of various other public facilities.

On the Modifiable Areal Unit Problem (MAUP) in healthcare accessibility measurement via the two-step floating catchment area (2SFCA) method.

Abstract. Accessibility, as an important theme in geospatial science, measures the potential of interaction between geographic entities. Originated in Hansen’s (1959) empirical model for land use planning, place-based accessibility becomes an integrated assessment of urban settlements in relation to social services and opportunities, such as employment, education, and entertainment. Traditional place-based accessibility models, such as the integral measure or the cumulative-opportunity measure (Kwan, 1998), are primarily dependent on the assessment of the supply (e.g., stores, restaurants), evaluating if goods or services could be delivered or reached at an acceptable cost (e.g., distance, time). This assessment overlooks the complex spatial interactions between the supply and demand, referred to as the “complementarity” (Haynes &amp;amp; Fotheringham, 1984). Recent development of the place-based accessibility theory revolves around the two-step floating catchment area (2SFCA) method (Luo &amp;amp; Wang, 2003). The model evaluates if the capacity of service facilities can cater to nearby demand in a two-step search process. Initially serving for the assessment of health care facilities, the model has been further modified to accommodate various urban planning scenarios (Chen, 2017). One compartment of the model in need of further evaluation is the distance decay. Although the 2SFCA model and its extensions have involved different distance decay functions, such as the Gaussian form and the kernel density form, there is a limited scope of work systematically comparing the performance and limitations of different 2SFCA models. In this study, we have proposed an analytic framework that includes six distance decay functions: the rectangular cumulative-opportunity (CUMR), negative-linear cumulative-opportunity (CUML), inverse-power gravity-type (POW), exponential gravity-type (EXP), and Gaussian gravity-type (GAUSS), and kernel density (KD) models. Examples of these distance decay functions are shown in Figure 1. Each model further consists of four variable scenarios, generating a total of twenty-four 2SFCA measures for comparison in a systematic manner. Using the datasets of point-based food stores (i.e., the supply) and population (i.e., the demand) in the state of Arkansas, the United States, three sets of sensitivity analyses have been conducted to compare the results derived from these twenty-four models. These analyses include (1) Pearson’s correlation between models, (2) assessment by urban-rural status, and (3) variability analysis of the catchment size. Observations about the sensitivity of the 2SFCA models to the distance decay function and the catchment size are drawn from the analyses, providing valuable information for better understanding the intricacy of the model compartments. For example, we have employed the coefficient of variation (CV), defined as the division of the standard deviation to the mean, to examine the spatial inequity of different 2SFCA models as a function of the catchment size (d0, in miles). As shown in Figure 2, all models have a large degree of variability with a small d0; when d0 increases to a certain threshold, CV becomes relatively convergent (d0 &amp;amp;geq; 9.5). It is also observed that POW20 has a higher level of variability than other models. In this respect, POW20 should be avoided in future model implementation as it derives a different spatial inequity pattern than other models. In addition to revealing the applicability of the models, the paper further draws two important conclusions. First, on a small analysis scale (e.g., community), the catchment size is the most important modeling variable. In this scenario, variation in the catchment size can cause a high degree of measurement uncertainties. Thus, it is a necessity to examine and justify the choice of the catchment size when applying the 2SFCA model to a small-scale analysis. Second, on a large analysis scale (e.g., state, province), the distance decay function is of critical importance. In this scenario, using the 2SFCA model without the distance decay will likely overestimate the supply-demand interaction and thus obfuscate the inequity pattern. In sum, the comparison and the sensitivity analysis outline the potential applicability and limitations of different 2SFCA models. It provides the theoretical rapport necessary to future applications of the model for various urban planning, service delivery, and spatial equity problems.

National Study of the Emergency Physician Workforce, 2020

Healthcare resources are often crucial but limited, requiring careful consideration and informed allocation based on population needs and potential healthcare access. In resource allocation settings, availability and accessibility of resources should be examined simultaneously. The two-step floating catchment area (2SFCA) method has been previously used to evaluate spatial accessibility to healthcare resources and services, and to address health-related disparities. The 2SFCA methods have regained significant popularity during the COVID-19 pandemic, as their application proved crucial in addressing priority public health data analysis, modeling, and accessibility challenges. However, comprehensive comparisons of the 2SFCA method input parameters in the context of public health concerns in Texas are lacking. Our study aims to (a) perform a comparative analysis of 2SFCA input parameters on patterns of spatial accessibility and (b) identify a 2SFCA method to guide evaluation of equitable allocation of scarce mental health resources for children and adolescents in Texas. We used the Texas Child Psychiatry Access Network (CPAN) data to assess county-level, regional patterns in access to pediatric psychiatric care, and to identify areas to expand CPAN to mitigate access-related disparities. Using the 2SFCA method, we further compared accessibility patterns across two kernel density distance decay functions for 10 catchment area specifications. As expected, spatial accessibility measures, such as the spatial accessibility ratio (SPAR), are sensitive to input parameters, particularly the catchment area. However, across all catchment area thresholds, two clusters of counties in southern and central Texas had particularly low accessibility, highlighting the opportunity for expanding the provider network in these areas. Identifying areas with low accessibility can help public health initiatives prioritize regions in need of improved services and resources. The incorporation of additional data on supply capacity and care-seeking behavior would aid in the refinement of estimates for spatial accessibility at the regional level and within larger urban centers.

Background: In the United States, alcohol use disorder (AUD) is common and costly but substantially undertreated. Rurality is an important determinant of health that may influence receipt of evidence-based alcohol-related care. In a large, national sample of Veterans Health Administration (VA) patients with AUD with documented and non-Hispanic Black, Hispanic, or non-Hispanic White race/ethnicity, we examine whether meeting national Healthcare Effectiveness Data and Information Set (HEDIS) quality measures for specialty addictions care and receiving evidence-based medications for AUD differs across patients living in urban, large rural, and small rural areas. Methods: VA electronic health record data were used to identify all patients with AUD documented in Fiscal Year 2012. Rurality was measured using a three-category rural and urban commuting area (RUCA) classification linked to patient zip code. Logistic regression models with clustered standard errors—iteratively adjusted for hypothesized confounders—were used to estimate the likelihood and marginal probabilities of receiving care for patients living in small and large rural areas, relative to urban areas. Primary outcomes included HEDIS initiation (any visit within 14 days of initial AUD visit after a 60-day period of no treatment), HEDIS engagement (2 or more AUD visits within 30 days of HEDIS initiation visit) and having any filled prescription for AUD medications (naltrexone, disulfiram, acamprosate, or topiramate). Results: For all outcomes, patients living in large and small rural areas had a lower likelihood of receiving evidence-based AUD treatment than patients living in urban areas (all p-values < 0.05); differences in marginal probabilities across groups were relatively small. Conclusions: In this national sample of VA patients with AUD, those living in more rural areas were less likely to receive evidence-based treatment for AUD than those living in urban areas. Further research is needed to investigate strategies to increase receipt of specialty care and pharmacotherapy in more rural areas.

The issue of reducing spatial disparities is one of the most pressing concerns for policymakers and planners, which consider a crucial focus in planning and public service, especially accessibility to healthcare. Accessibility and proximity are the principal keys to providing good public service. Therefore, a healthcare system that meets the requirements of availability and affordability will be useless if spatial accessibility is not provided equally to all demands (population). Many technics and methods exist to quantify accessibility, including the two-step floating catchment area (2SFCA) method, its widely used to measure healthcare accessibility based on the travel distance threshold. This research paper aims to use the 2SFCA method to measure the spatial healthcare accessibility in Batna City because the 2SFCA method offers to measure accessibility on both spatial and functional levels. The spatial level will consider the threshold distances between the health demand (population) and the health provider location (healthcare facilities); moreover, functional accessibility is measured based on facility to population ratio that will give a better overview of Batna's healthcare provider. As a result, the optimal threshold distance that offers balanced results between the spatial accessibility score and other WHO ratios will be a distance between 1000- and 1500-meters travel distance. In addition, the central census districts have a higher access score than the rest of the city's districts; most census districts that do not have accessibility (12% of the population) to healthcare facilities are concentrated in the southwest of Batna city.

The multi-modal two-step floating catchment area (MM-2SFCA) method is an extension of the two-step floating catchment area (2SFCA) method that incorporates the impact of different transportation modes, thereby facilitating more accurate calculations of the spatial accessibility of public facilities in urban areas. However, the MM-2SFCA method does not account for the impact of distance within the search radius on supply–demand capacities, and it assumes an idealized supply–demand relationship. This paper introduces the gravity model into the MM-2SFCA method, proposing a multi-modal gravity-based 2SFCA (MM-G2SFCA) method to better account for distance decay and supply–demand relationships. Furthermore, a standardized gravity model is proposed based on the traditional gravity model. This model imposes constraints on upper and lower limits for distance decay weights without compromising the fundamental curve characteristics of the gravity model, thereby avoiding extreme weight scenarios. The accessibility of public hospitals in Shenzhen is evaluated through the integration of basic geographic information data, resident travel data, and official statistical data. The findings demonstrate that the standardized gravity model effectively addresses the issue of excessively high local distance weights in the traditional gravity model, making it more suitable as a distance decay function. The MM-G2SFCA method improves the consideration of distance and supply–demand relationships, thereby facilitating a more rational distribution of accessibility on a global scale. This study discovers differences in the spatial allocation of public hospital resources across the Shenzhen’s districts. Accessibility within the metropolitan core is significantly higher than that outside the core. Additionally, there is a notable difference in the level of accessibility among the districts. Accessibility is found to be better in district centers and along the main traffic arteries.

Measuring spatial accessibility to primary health care services: Utilising dynamic catchment sizes