Two-step Floating Catchment Area Model Research Articles

Detecting heterogeneity of spatial accessibility to sports facilities for adolescents at fine scale: A case study in Changsha, China

Abstract It is crucial for social sustainability that adolescents have access to social sports services fairly. However, there are few research studies on requirements for sports facilities and spatial accessibility of adolescents at a fine scale. Further, identifying the heterogeneity of the relationship between spatial accessibility and other factors and their scales simultaneously would be conducive to reveal the variations of spatial accessibility effectively under the potential scale effect. This research aims to explore the heterogeneity of spatial accessibility to sports facilities at a fine scale in Changsha, China. The Gaussian-based two-step floating catchment area model is first employed to evaluate spatial accessibility. Then, multiscale geographically weighted regression (MGWR) is applied to examine the relationship between spatial accessibility and its associated factors. The mean accessibility in Yuelu District (0.158) is the highest as well, and the standard deviation (0.236) is also the highest one. Both the accessibility (0.019) and its standard derivation (0.029) in Furong District are the lowest. The results show that there is a lack of balance of spatial accessibility for the clusters with different accessibility levels distributed in the study area. Some socio-economic factors, such as housing price and nighttime light intensity, have significant impacts on spatial accessibility for adolescents with spatial and scale heterogeneity by using MGWR. Based on heterogeneous distribution and association, suggestions for promoting spatial accessibility to sports facilities for adolescents are proposed.

Accessibility to ERCP-performing hospitals among patients with pancreatic cancer living in SEER regions.

The two most common interventions used to treat painless jaundice from pancreatic cancer are endoscopic retrograde cholangiopancreatography (ERCP) and percutaneous transhepatic biliary drainage (PTBD). Our study aimed to characterize the geographic distribution of ERCP-performing hospitals among patients with pancreatic cancer in the United States and the association between geographic accessibility to ERCP-performing hospitals and biliary interventions patients receive. This is a retrospective cohort study using the Surveillance, Epidemiology, and End Results (SEER)-Medicare database for pancreatic cancer from 2005 to 2013. Multilevel models were used to examine the association between accessibility to ERCP hospitals within a 30- and 45-min drive from the patient's residential ZIP Code and the receipt of ERCP treatment. A two-step floating catchment area model was used to calculate the measure of accessibility based on the distribution across SEER regions. 7464 and 782 patients underwent ERCP and PTBD, respectively, over the study period. There were 808 hospitals in which 8246 patients diagnosed with pancreatic cancer in SEER regions from 2005 to 2013 received a procedure. Patients with high accessibility within both 30- and 45-min drive to an ERCP-performing hospital were more likely to receive an ERCP (30-min adjusted odds ratio [aOR]: 1.53, 95% confidence interval [CI]: 1.17-2.01; 45-min aOR: 1.31, 95% CI: 1.01-1.70). Furthermore, in the adjusted model, Black patients (vs. White) and patients with stage IV disease were less likely to receive ERCP than PTBD. Patients with pancreatic cancer and high accessibility to an ERCP-performing hospital were more likely to receive ERCP. Disparities in the receipt of ERCP persisted for Black patients regardless of their access to ERCP-performing hospitals.

Race, rurality and geographic accessibility to medication for opioid use disorder in the U.S.

ABSTRACT Disparities in geographic access to medication for opioid use disorder (OUD) are well documented. Further, historical implications of systemic racism and of the longstanding War on Drugs in the United States have driven both social and spatial inequities in access to treatment. This work builds on a previously published spatial access methodology that uses a gravity-based variant of the enhanced two-step floating catchment area model, to determine how OUD pharmacotherapy accessibility varies nationally at the census tract level. Medication for OUD (MOUD) accessibility scores are then analyzed by rurality and racial/ethnic segregation. The Getis-Ord Gi* statistic was used to identify clusters of high or low accessibility to MOUD, while the interaction index was used as a measure of segregation to assess the racial/ethnic population distribution. The results of the clustering statistic, and the associated significance values were then compared to rurality and interaction using the Chi-Square test to determine if hot or cold areas of access are independent of rurality and racial/ethnic spatial distributions. Lastly, the percentage of buprenorphine providers at capacity by census tract was calculated using the binary ‘at-capacity’ data attribute associated with each SAMHSA buprenorphine provider record. The results demonstrate distinct spatial variability of MOUD resources based on urbanicity and racial makeup that have significant implications for intervention or policy reform that seeks to encourage equal access to both treatment modalities.

Correlating Access to Primary Medical Care and Veterinary Care Providers: A Novel Application of Spatial Gravity Modelling.

Increasingly, health professionals are recognizing the need for a more holistic, or One Health, approach to wellness. Companion animals share the lives and homes of many Americans, and yet little research exists on the intersection of disparities of access to veterinary care and access to human health care. This research aims to fill that gap by exploring the use of a spatial model that identifies the relationship of supply and demand while also considering reductions as a function of travel time to a care facility. Four counties in Alabama were analyzed at the census tract level to determine the supply of primary care physicians and veterinary care providers. This research provides a unique application of the Enhanced Two-Step Floating Catchment Area model by independently examining access to each type of care and then comparing both access supply values at the census level. Results indicated a statistically significant positive relationship between access to both types of care, implying areas with lower access to primary care have concomitantly low access to veterinary care. Implications for practice include the introduction of this methodological approach, identification of future parameter specification research to improve the approach, and identification of an area of significant concern in the One Health framework. Further, the results can inform solution strategies such as offering integrated care interventions for both humans and their companion animal household members with direct use for policymakers aimed at increasing equitable access to health care across the One Health spectrum.

The Contributions of Population Distribution, Healthcare Resourcing, and Transportation Infrastructure to Spatial Accessibility of Health Care.

Population demand, healthcare resourcing, and transportation linkage are considered as major determinants of spatial access to health care. Temporal changes of the 3 determinants would result in gain or loss of spatial access to health care. As a remarkable milestone achieved by Targeted Poverty Reduction Project launched in China, the significant improvements in spatial access to health care served as an ideal context for investigating the relative contributions of these 3 determinants to the changes in spatial access to health care in a rural county. A national level poverty-stricken county, Chishui county from Guizhou province, China, was chosen as our study area. The enhanced two-step floating catchment area model and the chain substitution method were employed for analysis. The relative contributions of the 3 determinants demonstrated variations with villages. The relative contributions of healthcare resourcing were positive in all villages as indicated by sharp increases in healthcare resources. Population changes and transportation infrastructure expansion had both negative and positive effects on spatial access to health care for different villages. Decisionmakers should take into account the duration of travel time spent between where people live, where transport hubs are located, and where healthcare services are delivered in the process of formulating policies toward rural healthcare planning. For villages with poorly-established infrastructure, the optimization of population distribution and healthcare resourcing should be considered as the priority. A stronger marginal effect would be induced by transportation infrastructure expansion with increased spatial accessibility. This study provides empirical evidences to inform healthcare planning in low- and middle-income countries.

Measuring equality in access to urban parks: A big data analysis from Chengdu.

Spatial equality of parks is a significant issue in environmental justice studies. In cities with high-density development and limited land resources, this study uses a supply-demand adjusted two-step floating catchment area model (2SFCA), paying attention to residents' subjective preferences and psychological accessibility. It assesses equality of access to urban parks from two dimensions: spatial equality and quantitative equality at a fine scale of 100 × 100 m grid resolution. The spatial equality of urban parks in Chengdu is measured under different transportation modes (walking, cycling, and driving) based on multi-source geospatial big data and machine learning approaches. The results show: (1) There were significant differences in the spatial distribution of park accessibility under different modes of transportation. The spatial distribution under walking was significantly influenced by the park itself, while the distribution of rivers significantly influenced the spatial distribution under cycling and driving; (2) Accessibility to urban parks was almost universally equal in terms of driving, relatively equal in terms of cycling, and seriously unequal in terms of walking; (3) Spatial local autocorrelation analysis shows that park accessibility tended to be significantly clustered, with little spatial variation; and (4) The supply and demand of urban parks were relatively equal. The results can help urban planners to formulate effective strategies to alleviate spatial inequality more reasonably and precisely. The applied research methods can further improve the system of scientific evaluation from a new perspective.

Geographic disparities in access to Medication for Opioid Use Disorder across US census tracts based on treatment utilization behavior

Drug overdose is the leading cause of accidental death in the U.S. with deaths from opioid overdose occurring at a higher rate in rural areas. The gaps in the provision of healthcare services have been exacerbated by the opioid crisis leaving vulnerable populations without access to preventative care and education, harm reduction, both chronic and acute treatment of the symptoms of opioid use disorder (OUD), and long-term psychological support for those with OUD and their families. There has been a call in the literature -and a federal mandate-for increased access to opioid treatment facilities, but to date this access has not been operationalized using best practices in geography. Medication for Opioid Use Disorder (MOUD) with FDA-approved methadone or buprenorphine has been shown to increase treatment retention, reduce opioid use and associated health and societal harms, and reduce opioid related overdose, and as such is considered the most effective treatment for OUD. The objective of this study is to examine U.S. adults' spatial access to MOUD — specifically locations of certified Opioid Treatment Programs (OTPs) and DATA-waived Buprenorphine providers. A gravity-based variant of the enhanced two-step floating catchment area model is employed, where friction of distance is based on previously published willingness to travel distances for patients visiting OTPs, to assess how opioid agonist treatment accessibility varies across the nation. Findings suggest that there are extensive ‘treatment deserts’ where there is little to no physical access to MOUD, especially in rural areas. The significance of this work lies in the incorporation of treatment utilization behavior in the access metric, and the continued confirmation of gaps in access to OUD services despite federal efforts to improve accessibility.

Measuring COVID-19 vaccination coverage: an enhanced age-adjusted two-step floating catchment area model

BackgroundThere are only limited studies on access to COVID-19 vaccines and identifying the most appropriate health centres for performing vaccination in metropolitan areas. This study aimed to measure potential spatial access to COVID-19 vaccination centres in Mashhad, the second-most populous city in Iran.MethodsThe 2021 age structure of the urban census tracts was integrated into the enhanced two-step floating catchment area model to improve accuracy. The model was developed based on three different access scenarios: only public hospitals, only public healthcare centres and both (either hospitals or healthcare centres) as potential vaccination facilities. The weighted decision-matrix and analytic hierarchy process, based on four criteria (i.e. service area, accessibility index, capacity of vaccination centres and distance to main roads), were used to choose potential vaccination centres looking for the highest suitability for residents. Global Moran’s index (GMI) was used to measure the spatial autocorrelation of the accessibility index in different scenarios and the proposed model.ResultsThere were 26 public hospitals and 271 public healthcare centres in the study area. Although the exclusive use of public healthcare centres for vaccination can provide the highest accessibility in the eastern and north-eastern parts of the study area, our findings indicate that including both public hospitals and public healthcare centres provide high accessibility to vaccination in central urban part. Therefore, a combination of public hospitals and public healthcare centres is recommended for efficient vaccination coverage. The value of GMI for the proposed model (accessibility to selected vaccination centres) was calculated as 0.53 (Z = 162.42, P < 0.01). Both GMI and Z-score values decreased in the proposed model, suggesting an enhancement in accessibility to COVID-19 vaccination services.ConclusionsThe periphery and poor areas of the city had the least access to COVID-19 vaccination centres. Measuring spatial access to COVID-19 vaccination centres can provide valuable insights for urban public health decision-makers. Our model, coupled with geographical information systems, provides more efficient vaccination coverage by identifying the most suitable healthcare centres, which is of special importance when only few centres are available.Graphic abstract

Geospatial Analysis and Research on Social and Spatial Inequality of Compulsory Education: A Case Study of Hangzhou, China

Equal compulsory education is an important way to realize social and spatial equality, while the uneven allocation of educational resources in different regions and groups results in inequality of opportunity and solidification of social strata. Traditional research conducted on the basis of fixed search range ignores the special institutional background of Chinese school district system. In this paper, an improved Gaussian two-step floating catchment area model is developed taking into consideration the school district system, while the bivariate local spatial analysis method and geographically weighted regression model are employed to study the social and spatial differentiation of compulsory education accessibility and its capitalization effects in Hangzhou. Results show that (1) the improved Gaussian two-step floating catchment area model is more in line with the national condition of China’s “nearby schooling” policy; (2) the accessibility of compulsory schools in Hangzhou shows an obvious core-periphery typology, and the aggregation effect of primary school accessibility is more significant than that of secondary schools; (3) compared to groups with high socioeconomic status, vulnerable groups are highly disadvantaged in terms of access to educational services; (4) spatial heterogeneity exists in education capitalization, and the areas where education accessibility has the strongest impact on housing prices are in the central city with rich high-quality educational resources; (5) high-quality educational resources, high-priced communities, clusters of high socioeconomic status groups, and communities enjoying high-level education accessibility are highly consistent in all spaces, which is the spatial expression of educational inequality. The research on Hangzhou, a regional central city, provides a theoretical basis and technical support for the humanistic shift in the allocation of educational resources.

A geospatial analysis of Type 2 Diabetes Mellitus and the food environment in urban New Zealand

The aim of this research is to analyse the spatial epidemiology of Type 2 Diabetes Mellitus (T2DM) and investigate associations with the built environment in urban New Zealand. Data on T2DM was sourced from the New Zealand Virtual Diabetes Register (2016), and data on environmental variables sourced from the Ministry for Primary Industries and Territorial Authorities (2013–2016). Novel measures of the built environment using an enhanced two-step floating catchment area model were established using data on fast food outlets, takeaways, dairy/convenience stores, supermarkets and fruit/vegetable stores. Rates of T2DM per 1000 population and standardised morbidity ratios were computed and visualised for all urban areas. Getis Ord was used to assess spatial clustering, and Bayesian modelling was used to understand associations between T2DM and environmental variables. Results indicate that T2DM is influenced by demographic factors, spatially clustered and associated with accessibility to environmental exposures. Health-promoting resources, such as fruit/vegetable stores, were shown to have a consistently protective effect on T2DM while those considered detrimental to health showed varying, and largely insignificant, associations. This is the first study in New Zealand to spatially quantify the effects of multiple environmental exposures on population level T2DM for all urban areas using a geospatial approach. It has implications for both policy and future research efforts as a deeper knowledge of local environments forms a basis on which to better understand spatial associations between the built environment and health, as well as formulate policy directed toward environmental influences on chronic health conditions.

Modeling spatial access to cervical cancer screening services in Ondo State, Nigeria

BackgroundWomen in low- and middle-income countries (LMIC) remain at high risk of developing cervical cancer and have limited access to screening programs. The limits include geographical barriers related to road network characteristics and travel behaviors but these have neither been well studied in LMIC nor have methods to overcome them been incorporated into cervical cancer screening delivery programs.MethodsTo identify and evaluate spatial barriers to cervical cancer prevention services in Ondo State, Nigeria, we applied a Multi-Mode Enhanced Two-Step Floating Catchment Area model to create a spatial access index for cervical cancer screening services in Ondo City and the surrounding region. The model used inputs that included the distance between service locations and population centers, local population density, quantity of healthcare infrastructures, modes of transportation, and the travel time budgets of clients. Two different travel modes, taxi and mini bus, represented common modes of transit. Geocoded client residential locations were compared to spatial access results to identify patterns of spatial access and estimate where gaps in access existed.ResultsOndo City was estimated to have the highest access in the region, while the largest city, Akure, was estimated to be in only the middle tier of access. While 73.5% of clients of the hospital in Ondo City resided in the two highest access zones, 21.5% of clients were from locations estimated to be in the lowest access catchment, and a further 2.25% resided outside these limits. Some areas that were relatively close to cervical cancer screening centers had lower access values due to poor road network coverage and fewer options for public transportation.ConclusionsVariations in spatial access were revealed based on client residential patterns, travel time differences, distance decay assumptions, and travel mode choices. Assessing access to cervical cancer screening better identifies potentially underserved locations in rural Nigeria that can inform plans for cervical cancer screening including new or improved infrastructure, effective resource allocation, introduction of service options for areas with lower access, and design of public transportation networks.

Urban Green Space Accessibility and Distribution Equity in an Arid Oasis City: Urumqi, China

Urban green space (UGS) is crucial to the healthy development of urban residents. However, UGS that is accessible can benefit residents to an even greater degree. Based on the two-step floating catchment area model (2SFCA) and the location quotient (LQ), we analyzed the changes from 1999 to 2019 in UGS walking accessibility and equity in built-up areas of Urumqi at different administrative levels, and how UGS policy affects the improvement of accessibility. The results showed that UGS accessibility and equity are not evenly distributed at different administrative levels and UGS categories. Although the overall UGS accessibility and equity has improved with policy implementation, these changes are caused by metro-level UGS construction in urban fringe areas. The improvement in UGS accessibility at the neighborhood level in densely populated areas is neglected, which leads to a mismatch between UGS construction and population distribution. In addition, the accessibility of UGS is also limited by geographical location, population density, road distribution, and water shortage in arid metropolitan Urumqi. Our research results provide a theoretical basis for Urumqi and other cities in the optimization of UGS structure and the realization of social equity.

Dynamic healthy food accessibility in a rapidly urbanizing metropolitan area: Socioeconomic inequality and relative contribution of local factors

The socioeconomic status (SES) related disparities in healthy food accessibility have been heatedly debated. Theoretically, a gap remains in the literature about how healthy food accessibility changes over time and the relative contribution of local factors to the change. Methodologically, one main obstacle to this issue emerges on how to address the nested structural interactions among SESs across different levels. This paper first proposes a novel theoretical framework on healthy food accessibility from a spatiotemporally dynamic perspective. Guided by this framework, we employ the enhanced two-step floating catchment area model to examine the dynamic accessibility to four types of healthy food stores (i.e., vegetable markets, supermarkets, seafood markets, and fruit stores) from 2016 to 2018 across communities within the Hangzhou metropolitan area, China. The chain substitution method is further utilized to quantify the relative contributions of local factors, including population demand, healthy food supply, and transportation linkage. Multilevel regression is finally applied to analyze the associations between healthy food accessibility and the nested SESs across community and subdistrict levels. Results reveal that the dynamics of healthy food accessibility and the contributions of the local factors substantially vary depending on the type of healthy food stores and over time. Social inequality in accessibility to supermarkets and fruit stores is much greater than that to vegetable markets. The impact of the SES at the subdistrict level is greater than that at the community level. This study demonstrates a new methodological procedure and can offer new insights into healthy food accessibility in rapidly urbanizing metropolitan areas.

Disparity in Spatial Access to Public Daycare and Kindergarten across GIS-Constructed Regions in Seoul, South Korea

In developed countries with decreasing fertility rates, the provision of public daycare and kindergarten (PDK) is considered to be an important policy for boosting national birth rates. Since PDK is free, its spatial accessibility becomes the most critical factor for parents in choosing the service. The study uses the popular two-step floating catchment area model (2SFCA) to analyze the spatial accessibility of PDKs at a 100 m × 100 m cell level in Seoul, South Korea. A GIS-automated regionalization method, Mixed-Level Regionalization (MLR), is employed to divide the study area into homogenous regions based on a concentrated disadvantage index (CDI). The analysis then proceeds to examine the disparity of PDK accessibility across these constructed regions. The result empowers parents to be informed of the access of PDKs in their current neighborhoods or to look for neighborhoods with adequate access. Several policy measures are proposed for improving overall accessibility of PDKs and more so for underserved populations.

Enhancing the Two-Step Floating Catchment Area Model for Community Food Access Mapping: Case of the Supplemental Nutrition Assistance Program

In this article, a Gaussian-based two-step floating catchment area (2SFCA) model is applied to evaluate the geographical accessibility to Supplemental Nutrition Assistance Program (SNAP)-authorized retailers. First, the proposed method considers the interaction between the food supply (in terms of categorized benefit redemptions) and demand (in terms of benefit-receiving households). Second, the model is used to visualize food access patterns at the level of refined administrative units (i.e., census block groups). The developed food access metric was compared to the U.S. Department of Agriculture (USDA) Food Access Research Atlas, justifying the validity of this new method for small area estimation. The following are important observations: (1) the choice of catchment size had a considerable impact on the accessibility measure in urban areas (or when small statistical units are used); (2) the 2SFCA measurement had a higher level of correspondence with that of the USDA Atlas at a smaller catchment size for identifying low food access units; and (3) there was no significant inequality regarding SNAP accessibility with respect to different socioeconomic deprivation variables. This new method can better assist the SNAP administration with store authorization on a refined geographic scale. Key Words: food access, inequality, scale, Supplemental Nutrition Assistance Program (SNAP), two-step floating catchment area (2SFCA).

Determining spatial access to opioid use disorder treatment and emergency medical services in New Hampshire

This research presents an analysis of spatial access to both opioid use disorder treatment facilities and emergency medical services in New Hampshire during 2015–2016, a period during which there was a steep increase in unintentional overdoses involving fentanyl. For this research, spatial access was computed using the enhanced two-step floating catchment area model combined with the Huff model to assess access across New Hampshire and gives attention to supply-side parameters that can impact spatial access. The model is designed to measure access to healthcare services for opioid use disorder patients offered at treatment centers or from buprenorphine treatment practitioners, as well as from emergency medical services across New Hampshire. A composite index of accessibility is proposed to represent overall access to these different treatment services for opioid use disorder patients. Geospatial determinants of spatial access included street network distances, driving times and distance decay relationships, while other key factors were services availability and population demand. Among the towns with the highest composite access scores, approximately 40% were metropolitan locations while 16% were rural towns. The insights from this research showed that for this period, while the opioid crisis was impacting many towns in New Hampshire, high levels of access to treatment services were not uniform across the state. When comparing the access results with data on the towns of residence for individuals who died from unintentional overdoses involving fentanyl during 2015 and 2016, estimates found that approximately 40% of the towns were not estimated to be in the highest class of access to treatment services at the time. This research provides information for local public health officials to support planning strategies to address opioid use disorder treatment access in high-risk regions.

Accessibility to Primary Health Centre in a Tribal District of Gujarat, India: application of two step floating catchment area model

Accessibility to the health centre is poorly understood in most of the developing countries. Regardless of development, it is a challenge to provide healthcare services to the entire population. To measure the accessibility of Primary Health Centre (PHC), a two-step floating catchment area model has been used in a tribal district (Dahod) of Gujarat, India. This model catches service area twice. In the first step, it considers the healthcare facility demand for the population to population ratio and in the second step measures the accessibility by summing up the all the values of those service areas within the threshold. It has been observed that there is an apparent disparity in the accessibility of healthcare services. In few pockets of the district, the accessibility is less due to a shortfall of 24 against 66 PHCs or insufficient road network. In other words, the villagers had to travel a long distance for seeking healthcare facility. The study identifies the rendered dark zones of the district and helps the researchers and policymakers to develop infrastructure in terms of improving road network or identify the optimal location for more PHCs.

Healthy aging with parks: Association between park accessibility and the health status of older adults in urban China

Accessibility is a crucial element reflecting the potential availability of parks. By conducting a cross-sectional study of 700 older adults sampled from 30 communities in Wuhan, China, we examine the association between the accessibility of parks and the health status of older adults. A varying two-step floating catchment area model was developed to measure the accessibility of parks for older adults that simultaneously considered the physical environment and sociopersonal context. Based on the results of a logistic regression analysis, older adults with the greatest access to parks experience significantly lower odds of cardio-cerebral vascular diseases, joint diseases and endocrine diseases than their counterparts with the least access to parks. The effects of the physical environment and sociopersonal context on the accessibility of parks and health status are also discussed. In general, these two factors jointly influence the potential alternatives to parks and participation in park-based activities among older adults and in turn affect the health benefits for older adults. This study provides empirical support for the role of parks in supporting healthy aging. It also emphasizes the need for more comprehensive economic planning strategies to improve park accessibility and promote healthy aging in transitional cities.

Modelling the spatial accessibility of the elderly to healthcare services in Beijing, China

In the context of rapid population aging, Beijing is facing great challenges in providing healthcare services for the elderly. The objective of this study is to measure the spatial accessibility of the elderly to healthcare services in Beijing. A major challenge is that healthcare services are not exclusive for the elderly, so the elderly must compete with the non-elderly for access to healthcare services. In this study, we have developed a multi-mode and variable-demand two-step floating catchment area model for measuring spatial accessibility of the elderly to healthcare services, taking into account the competition between the elderly and non-elderly. This is modeled by differences in demand intensity and mobility. The elderly have a higher demand intensity and are disadvantaged in mobility due to their higher dependence on public transportation than the non-elderly. To improve the elderly’s healthcare accessibility, more healthcare resources should be allocated and the public transportation to hospitals should be improved, especially in peripheral areas. The proposed model can also be applied in other scenarios considering multiple population groups with different demand intensity for public services and mobility.

Urban green space accessibility changes in a high-density city: A case study of Macau from 2010 to 2015

Urban Green Spaces (UGSs) are important for urban residents' well-being, especially in dense urban areas. This study uses Macau, a high-density city in Asia, as a case study area and tracks changes in the distribution of UGS accessibility across space and across population groups from 2010 to 2015. Based on the two-step floating catchment area model (2SFCA), the results indicate that UGS accessibility is distributed unevenly across space and population groups in Macau. Over time, however, UGS accessibility became more evenly distributed, despite the decline in overall UGS accessibility. These changes are attributable to the policies of upgrading UGSs and building micro-scale UGSs. These results shed light on how future policies can enhance UGS equity in high-density urban areas.