The two-step floating catchment area (2SFCA) method is a method for combining a number of related types of information into a single, immediately meaningful, index that allows comparisons to be made across different locations. Its importance lies in the improvement over considering the individual sources of information separately, where none on its own provides an adequate summary.
The two-step floating catchment area (2SFCA) method is a special case of a gravity model of spatial interaction that was developed to measure spatial accessibility to primary care physicians. [1] [2] 2SFCA is based on the accessibility measure developed by Shen (1998), who used it to compare accessibility to jobs among workers residing in different locations and traveling by different transportation means, and more generally, to measure accessibility to spatially distributed opportunities that have capacity limitations (i.e., rival goods). 2SFCA was inspired by the spatial decomposition idea first proposed by Radke and Mu (2000).
The 2SFCA method not only has most of the advantages of a gravity model, but is also intuitive to interpret, as it uses essentially a special form of physician-to-population ratio. It is easy to implement in a GIS environment. [2] [3] [4] In essence, applying the accessibility measure formulated by Shen (1998) the 2SFCA method is an automated procedure for measuring spatial accessibility as a ratio of primary-care physicians to population, combining two steps:
It has been recently enhanced by considering distance decay within catchments [5] and called the enhanced two-step floating catchment area (E2SFCA) method.
Furthermore, the use of capping certain services according to nearby population size, can improve the accuracy when analyzing across areas of different environments [6] (i.e. rural and urban).
The method has been applied to other related public health issues, such as access to healthy food retailers. [7]
A geographic information system (GIS) consists of integrated computer hardware and software that store, manage, analyze, edit, output, and visualize geographic data. Much of this often happens within a spatial database; however, this is not essential to meet the definition of a GIS. In a broader sense, one may consider such a system also to include human users and support staff, procedures and workflows, the body of knowledge of relevant concepts and methods, and institutional organizations.
Remote sensing is the acquisition of information about an object or phenomenon without making physical contact with the object, in contrast to in situ or on-site observation. The term is applied especially to acquiring information about Earth and other planets. Remote sensing is used in numerous fields, including geophysics, geography, land surveying and most Earth science disciplines. It also has military, intelligence, commercial, economic, planning, and humanitarian applications, among others.
Geomatics is defined in the ISO/TC 211 series of standards as the "discipline concerned with the collection, distribution, storage, analysis, processing, presentation of geographic data or geographic information". Under another definition, it consists of products, services and tools involved in the collection, integration and management of geographic (geospatial) data. Surveying engineering was the widely used name for geomatic(s) engineering in the past. Geomatics was placed by the UNESCO Encyclopedia of Life Support Systems under the branch of technical geography.
Community health refers to non-treatment based health services that are delivered outside hospitals and clinics. Community health is a subset of public health that is taught to and practiced by clinicians as part of their normal duties. Community health volunteers and community health workers work with primary care providers to facilitate entry into, exit from and utilization of the formal health system by community members as well as providing supplementary services such as support groups or wellness events that are not offered by medical institutions.
Health geography is the application of geographical information, perspectives, and methods to the study of health, disease, and health care. Medical geography, a sub-discipline of, or sister field of health geography, focuses on understanding spatial patterns of health and disease in relation to the natural and social environment. Conventionally, there are two primary areas of research within medical geography: the first deals with the spatial distribution and determinants of morbidity and mortality, while the second deals with health planning, help-seeking behavior, and the provision of health services.
Spatial analysis is any of the formal techniques which studies entities using their topological, geometric, or geographic properties. Spatial analysis includes a variety of techniques using different analytic approaches, especially spatial statistics. It may be applied in fields as diverse as astronomy, with its studies of the placement of galaxies in the cosmos, or to chip fabrication engineering, with its use of "place and route" algorithms to build complex wiring structures. In a more restricted sense, spatial analysis is geospatial analysis, the technique applied to structures at the human scale, most notably in the analysis of geographic data. It may also be applied to genomics, as in transcriptomics data.
A dasymetric map is a type of thematic map that uses areal symbols to visualize a geographic field by refining a choropleth map with ancillary information about the distribution of the variable. The name refers to the fact that the most common variable mapped using this technique has generally been population density. The dasymetric map is a hybrid product combining the strengths and weaknesses of choropleth and isarithmic maps.
The modifiable areal unit problem (MAUP) is a source of statistical bias that can significantly impact the results of statistical hypothesis tests. MAUP affects results when point-based measures of spatial phenomena are aggregated into spatial partitions or areal units as in, for example, population density or illness rates. The resulting summary values are influenced by both the shape and scale of the aggregation unit.
Time geography or time-space geography is an evolving transdisciplinary perspective on spatial and temporal processes and events such as social interaction, ecological interaction, social and environmental change, and biographies of individuals. Time geography "is not a subject area per se", but rather an integrative ontological framework and visual language in which space and time are basic dimensions of analysis of dynamic processes. Time geography was originally developed by human geographers, but today it is applied in multiple fields related to transportation, regional planning, geography, anthropology, time-use research, ecology, environmental science, and public health. According to Swedish geographer Bo Lenntorp: "It is a basic approach, and every researcher can connect it to theoretical considerations in her or his own way."
In human geography, a catchment area is the area from which a location, such as a city, service or institution, attracts a population that uses its services and economic opportunities. Catchment areas may be defined based on from where people are naturally drawn to a location or as established by governments or organizations for the provision of services.
A food desert is an area that has limited access to food that is plentiful, affordable, or nutritious. In contrast, an area with greater access to supermarkets and vegetable shops with fresh foods may be called a food oasis. The designation considers the type and the quality of food available to the population, in addition to the accessibility of the food through the size and the proximity of the food stores.
The gravity model of migration is a model in urban geography derived from Newton's law of gravity, and used to predict the degree of migration interaction between two places. Newton's law states that: "Any two bodies attract one another with a force that is proportional to the product of their masses and inversely proportional to the square of the distance between them."
Geographic information systems (GISs) and geographic information science (GIScience) combine computer-mapping capabilities with additional database management and data analysis tools. Commercial GIS systems are very powerful and have touched many applications and industries, including environmental science, urban planning, agricultural applications, and others.
A spatial distribution in statistics is the arrangement of a phenomenon across the Earth's surface and a graphical display of such an arrangement is an important tool in geographical and environmental statistics. A graphical display of a spatial distribution may summarize raw data directly or may reflect the outcome of a more sophisticated data analysis. Many different aspects of a phenomenon can be shown in a single graphical display by using a suitable choice of different colours to represent differences.
Head/tail breaks is a clustering algorithm for data with a heavy-tailed distribution such as power laws and lognormal distributions. The heavy-tailed distribution can be simply referred to the scaling pattern of far more small things than large ones, or alternatively numerous smallest, a very few largest, and some in between the smallest and largest. The classification is done through dividing things into large and small things around the arithmetic mean or average, and then recursively going on for the division process for the large things or the head until the notion of far more small things than large ones is no longer valid, or with more or less similar things left only. Head/tail breaks is not just for classification, but also for visualization of big data by keeping the head, since the head is self-similar to the whole. Head/tail breaks can be applied not only to vector data such as points, lines and polygons, but also to raster data like digital elevation model (DEM).
Primary Care Service Areas are geographic areas that are self-sufficient markets of primary care. These areas are designed in a manner such that the majority of patients living in these areas use primary care services form within the area. This ensures that any geographic targeting of policies and resources reach the patients they are meant for. These geographies have been created in Australia, United States and Switzerland using big data and Geographic information systems. In Australia, while they have been developed for the state of New South Wales, they have not found application among policymakers, where, as of 2016 much larger geographies called Primary Health Networks are used for primary care management. However, they have found an especially wide audience amongst policymakers and researchers in the United States, where they were first developed. Thus for example the Health Resources and Services Administration uses them to designate areas of workforce shortage. Primary Care Service Areas are thus for example an appropriate geography for measuring primary care physician supply or geographic access to General practitioners.
Geography of disability is a multi-disciplinary branch of human geography which studies the experiences of people with disabilities and the extent to which disability in a population can be influenced by its geographical location. Potential components of studies in a geographical analysis include the environment, politics, incidental and additional supports, and the socio-economic landscape of the region being examined. This field has become increasingly important as policymakers have become aware of the need to ensure equal access to community resources for all individuals, regardless of mobility challenges.
Concepts and Techniques in Modern Geography (CATMOG), is a series of 59 short publications, each focused on an individual method or theory in geography.
The uncertain geographic context problem or UGCoP is a source of statistical bias that can significantly impact the results of spatial analysis when dealing with aggregate data. The UGCoP is very closely related to the Modifiable areal unit problem (MAUP), and like the MAUP, arises from how we divide the land into areal units. It is caused by the difficulty, or impossibility, of understanding how phenomena under investigation in different enumeration units interact between enumeration units, and outside of a study area over time. It is particularly important to consider the UGCoP within the discipline of time geography, where phenomena under investigation can move between spatial enumeration units during the study period. Examples of research that needs to consider the UGCoP include food access and human mobility.
SaTScan is a software tool that employs scan statistics for the spatial and temporal analysis of clusters of events. The software is trademarked by Martin Kulldorff, and was designed originally for public health and epidemiology to identify clusters of cases in both space and time and to perform statistical analysis to determine if these clusters are significantly different from what would be expected by chance The software provides a user-friendly interface and a range of statistical methods, making it accessible to researchers and practitioners. While not a full Geographic Information System, the outputs from SaTScan can be integrated with software such as ArcGIS or QGIS to visualize and analyze spatial data, and to map the distribution of various phenomena.