Use of GIS in public health is currently limited to tracking immunizations, disease surveillance, and establishing new service areas. The potential of GIS to improve planning, implementation and monitoring of programs and to inform policymaking processes for universal access to healthcare is grossly underutilized. Major reasons for restricted use are paid access to GIS software and difficult interpretation for non-GIS professionals. WebGIS technologies present an opportunity for non-GIS public health professionals to present complex data and findings in simpler manner. Conventional GIS methods and Geovisualization are compared and contrasted in this paper using data from the MATIND project in the Gujarat state of India. In-depth literature review on GIS techniques used in health implementation research was conducted. In this paper, MATIND data have been used for comparing conventional GIS methods with a newer web based GIS tool-Geovisualization. GIS software is more useful for analytical purposes; whereas web based geovisualization techniques are much better for visualization and easy interpretation of results by non GIS public health researchers. As the images are easy to interpret, interactive/dynamic and not much technical expertise is required to perform basic analysis, the tool is useful for policy makers and planners. Geovisualization provides a user-friendly tool for presenting large scale community based survey data. Increased use of this tool will help to present implementation research in a creative way to the program planners and policy makers. For program managers, it is a useful tool to monitor implementation and impact of a program to improve health of population.
Complex and multidimensional data are examined to assemble meaningful information to improve planning, implementation and monitoring of programs and evidence based policymaking processes to improve population health [
Recently, Geographical Information System (GIS) has emerged as an innovative and important component of research and practice in public health [
Geovisualization is increasingly being used to inform public health research, planning and decision making in developed countries [
Applications of GIS methods require accurate transformation of location information from the data into geographic objects; this process is known as geocoding (latitude and longitude). Geocoding which is transformation of quantitative data to GIS data is not only tough work but also very tedious and base pillar for any visualization with its rewards. Geocoded data can be processed in three major ways before visualization as described here:
Attempt to display of the data points such as public and private health facilities, mothers’ home, village settlements etc. It is useful for defining areas of case occurrences, visual inspection of spatial clusters of patients or health facilities and analyzing health care resources distribution. An example of point pattern analysis in maternal health is the geographic uptake of a government scheme such as “Chiranjeevi Yojana” (CY) in the MATIND data.
Vectors or road lines are graphic resources that aid understanding the proximity and accessibility of patients to health care facilities. Arrows with widths proportional to the volume of flow between areas are important tools to evaluate the health care utilization of different locations.
For spatial descriptive analysis, the administrative boundary like village, block and District data on maps, with the variable of population, no. of house hold and no. of CY users can be used to represent the data in a specific dimension.
Frequently used maps in the public health research are Dot-density and Chloropleth maps [
Choropleth maps are area maps in which polygons are shaded, colored, or patterned according to the value of a given attribute for each polygon. Choropleth maps are also called thematic maps or Shaded maps. An example of a choropleth map for concentration of CY users in a district is shown in “
It is important to choose the right features for map presentations as the choice of color, pattern, size, polygon shape, and class intervals can impact how one interprets the information presented in a map. Single-color maps with varying color intensity (shades) are often an effective means of presenting data, but the use of differing patterns can help a black-and-white or grey-scale map. Similar-size polygons are recommended to the extent possible, as a few large polygons can dominate a map, leading to misinterpretation of information. Proportions or rates can be displayed by different class interval schemes, such as equal intervals (equal ranges of values) or quintiles (equal number of polygons falling into each class defined by dividing the range of values). The latter technique is particularly useful for presenting skewed data where distribution of utilization is not known or is very different.
Geovisualization is the process of geospatial data analysis where visualization is enabled through tools by the convergence of information, cartographic and geographic methods [
Addition of novel geo-web tools such as application programming interfaces (APIs) and open-source geospatial analysis coding packages in the Web 2.0 has further improved the utility through the positivistic approach [
In the context of WebGIS, data representation is called “the science of virtual space”, or the way space is constructed, reconstructed, represented and finally interpreted through a specific method [
Python program was used to extract the MATIND data from the REDCap [
The best part of the tool is hosting large datasets on the cloud that can be accessed, edited and updated remotely and no longer needs to be on an individual hard drive or server. Subsequently, the data can be created
and/or managed as well as accessed and utilized by a group of actors including: governments, citizens, civil society, businesses or academia on a variety of platforms without needing special software. This is largely due to the convergence of geospatial data standards (led by the Open GIS Consortium) promoting interoperability between and within traditional GIS methods and Web-GIS applications such as geoweb [
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Here geovisualization is an HTML file (webpage) that uses the Google Maps API platform to display spatial data. A drop down menu of individual and aggregate level spatial indicators displayed in the bottom corner on the right side of the webpage allows the user to select the indicator/layer of their choice. As users explore the data, they are able to view all the attributes of each point or polygon by clicking the point of interest and viewing its attributes in a side window. To facilitate usability and reduce cognitive issues pertaining to cluttering the user is able to zoom and pan throughout the map, as well as change the style of the map (satellite, road map, custom, etc.)
Both conventional GIS methods and Geovisualization have their advantages and limitations. Decision of which technique to be used, depends on the purpose. For example, conventional GIS techniques are better for in- depth spatial data analysis while Geovisualization has superior spatial data display.
Currently, the scope of using the technique of geovisualization is widening from exclusive use by GIS experts, innovators and early adopters towards a broader audience of non-GIS users including epidemiologists, policy makers and program planners. MATIND Gujarat data show that Geovisualization allows a number of variables to be displayed in a single view and gives the user an improved understanding of the complex relationship between these variables. For example, to understand the dynamic relationship between CY use and its predictors in the study areas such as proportion of CY eligible women, number of CY providers and their spatial distribution (as seen in
As Slocum et al. suggest, “The most sophisticated technology will be of little use if people cannot utilize it ef- fectively” [
complex and labor intensive process of development of the tool worthwhile. This could be extended to the different areas of public health to evaluate the unmet needs by geographic areas which are important for realistic evaluation and to prioritize resource allocation for low resource environments such as India for optimal use and maximum possible coverage. In single line the conclusion is that GIS technologies work hard for program managers and planners without hard work by program managers and planners to learn advanced GIS techniques. Apart from ease of use, it is cheaper option to software based GIS technology and once created can be used for a long time by multiple stakeholders.
Public health experts are using GIS techniques sparsely due to difficulty in learning the technology and the cost of software. Geovisualization provides a user-friendly tool for presenting large scale community based survey data or routinely collected HMIS data without losing the complexity. Dynamic, interactive, and temporal geovisualization make it possible for non-GIS experts to understand and disseminate public health data which are inherently spatial in nature and cannot, as easily, be presented through the use of paper based GIS maps or by quantitative analysis only.
Conceptualization: SY, KV, DVM. Analysis: SY, CH, AU. Writing: SY, KV, CH. Review and critical comments: KV, DVM.
The authors declare that they have no competing interests.
The research leading to these results has received funding from the European Community’s Seventh Framework Programme under grant agreement No. [