GIS Internet Map Servers for Health Applications

Carol L. Hanchette, Ph.D.Rebecca D. Martin, Ph.D.

Research Triangle InstituteResearch Triangle Park, NC

GIS and Health Services Research

Physician/facility location and allocation Market and hospital service areas Delivery of health and community services to

welfare recipients (DSS clients, childcare, employment, public transit)

Census tract rankings for family services (factors identified, ranked, mapped by quintile)

Health and Risk Factor Data to ID High Risk Areas

Childhood lead poisoning Immunization “Pockets of Need” (logistic

regression model used with immunization survey, birth certificates, census data)

Prediction of Teen Live Birth Rates using Census Data (logistic regression using 4 indicators)

Health and Risk Factor Data to ID High Risk Areas

What is GIS?

A set of tools for processing spatial data into information for enhanced decision making

A relational database management system where each record in every database is tied to a geographic location

Spatial and Attribute Data

Spatial data contain information about location, dimensions, shape, associations and relationships.

Attribute data describe the non-spatial components of the database.

Linked through a geocode (e.g. county, zip code, street address)

Spatial and Attribute Data

Barriers to GIS Use

Lack of trained GIS staff

Cost of unavailibility of spatial

data

Costs of purchasing GIS software

GIS Technology Trends

Mini-computers Unix

workstations PCs

Command line Graphical User

Interfaces Internet Map Server

Internet Map Server Technology

Hardware, software and data reside on GIS server

Mapping and spatial analysis capabilities are accessed via Web browser

Access: public OR password-protected

No training needed Customization/tool development

Internet Map Server Technology

National Cancer InstituteAtlas of Cancer Mortality

Venipuncture Project Management

Venipuncture Project Management

Central Cancer Registry Operations Management

Central Cancer Registry Operations Management

Iowa: patients, cities, hospitals and reporting rates

Central Cancer Registry Operations Management

Tennessee: View all patients within 75 miles of Johnson City

Central Cancer Registry Operations Management

Spatial Query of Reporting Rate

Visualization and Analysis of Cancer Data

Spatially enabling cancer data:

• Automated geocoding• Address matching• Data aggregation to

maintain confidentiality• Provision of services

• Distance to patient

• Access to care

Visualization and Analysis of Cancer Data

• Link to census and health outcomes data

Visualization and Analysis of Cancer Data

Quality Control of Geographic Identifiers

Geocode data

Use polygon overlay techniques or spatial query to examine correspondence of geographic identifiers (geocodes)

Overlay GIS county boundary file to assign correct county to patient records, then compare.

North Carolina Toxic Release Inventory Sites

Sites (represented by pink dots) that lie outside North Carolina have incorrectlatitude/longitude coordinates.

Over 1300 sites in NC, more than 100 located outside of state.

Greenland sites: reversed lat/longs

Quality Control of Geographic Identifiers

North Carolina state agency health database example

265,492 records

Only 158,552 (59.72%) with zip code, county and city correspondence

County of patient vs. county of health department

Duplication of county/city names: Henderson County in western North Carolina; town of Henderson in north-central North Carolina

Duplicate place names: 9 Bethel, 9 Five Points, 9 New Hope

Different coding schemes (use Federal Information Processing Standard (FIPS) whenever possible