South-East Asia Regional Conference on Epidemiology

208 | <strong>South</strong>-<strong>East</strong> <strong>Asia</strong> <strong>Regional</strong> <strong>Conference</strong> on Epidemiology
The MEGAPHONE® GIS being primarily a tool for representing health-related environmental
exposures, the system incorporates only limited health outcomes data. Such data include the complete
births and deaths files for the Montreal metropolitan region, coded at the level of the forward sortation
area (first three digits of the six-digit postal code). Birth information includes the location of the
birth, birth weight, length of pregnancy and mother’s residential location, marital status, education
and mother tongue. Death information includes the cause of death, age at death, place of death and
deceased’s marital status, home language and residential location. Where agreed upon, individuallevel
survey data from researchers collaborating in the use of MEGAPHONE® are also integrated. A
schematic representation of the GIS is given in Fig. 5.
Value-added components of the MEGAPHONE® GIS
Environmental data are structured and stored in a relational system architecture, specifically, an opensource
object-relational data-basing system (an early version of the system was transitioned from
Microsoft Access to PostgreSQL). Metadata for files (e.g. data source, year, description, coverage)
are compliant with international standards for metadata (OGC – Open Geospatial Consortium, FGDC
– Federal Geographic Data Committee and ISO – International Organisation for Standardisation).
Tools are also provided for automating the updating of files as new data become available, with
automatic updating of the MEGAPHONE catalogue with new metadata.
Beyond data and metadata, MEGAPHONE® includes: (i) a catalogue with relational indicator
classification typology, an executable application for navigating metadata and conceptual sorting of
indicators; (ii) tracking software for compiling research project data (detailed information on projects,
researchers and groups using MEGAPHONE® and their associated products); and (iii) sophisticated
tools including a geodatabase (ArcGIS, ESRI) with geographical files containing geo-referenced
spatial units – points, lines and polygons for geo-coding, upscaling or downscaling of data, and address
locator software for geo-coding address or postal code data files. The ability of a GIS to account for
different boundary units and scales of information, notably where boundaries do not correspond or
align, and to move between layers of data, is exploited by MEGAPHONE®. Spatial analysis tools
(buffers, convex hulls, segregation measures and macros for recalculation of data values for changed
census boundaries) and spatial sensitive statistical methods (spatial autocorrelation, geographically
weighted regression and centrographic analysis) are integrated for the derivation of spatially-informed,
value-added data to extend beyond the raw data within the system.
Among the most important tools in MEGAPHONE® is its catalogue with a relational indicator
classification typology for navigating metadata and conceptual sorting of indicators. This tool was
originally developed as an adaptation of existing international indicator frameworks which were
integrated and extended to enable relevance to disadvantaged Aboriginal communities in industrialized
nations. This allows the focus of various national indicator classification systems to be extended to
include elements relevant to any disadvantaged sub-population.
As described elsewhere(25,26), indicator frameworks which inform the MEGAPHONE typology
include those developed and used by major international (e.g. Organisation for Economic Cooperation
and Development) and national organisations (e.g. Statistics New Zealand) and agencies for
general population (e.g. Health Canada) and Indigenous population statistics (e.g. Australian Office
for Aboriginal and Torres Strait Islander Health), and locally-oriented community-based indicator
projects (e.g. Oregon Benchmarks) used to organise indicators. In total, 33 frameworks were studied.
The “German System of Social Indicators” (German Social Science Infrastructure Services Social
Indicators Department, 2004) was determined to be the most thorough and systematic and was used
as the foundation of the MEGAPHONE® typology. The nomenclature used for hierarchical levels
of the framework used in the “German System of Social Indicators” was adapted. The three levels of