GIS Software Applications in
Epidemiology
Marcus Liscombe
Brent Croft
GISC 6383 - GIS MANAGEMENT AND IMPLEMENTATION
What is Epidemiology?
• Epidemiology is:
“The study of why diseases occur and how often
diseases occur in different groups of people.
Or simply:
“The study of disease distribution in
populations”
http://bmj.bmjjournals.com/epidem/epid.1.html
Why is Epidemiology Important?
• Identification: Descriptive epidemiology surveys a
population to see what segments (e.g., age, sex, ethnic
group, occupation) are affected by a disorder, follows
changes or variations in its incidence or mortality over
time and in different locations, and helps identify
syndromes or suggest associations with risk factors.
• Prevention: Epidemiologic data on diseases is used to
find those at high risk, identify causes and take
preventive measures, and plan new health services
http://bmj.bmjjournals.com/epidem/epid.1.html
History of GIS and Epidemiology
• In 1854 Dr. John Snow was able to pinpoint a cause of cholera outbreak In
London by the following:
“…He went to the Register of Deaths and got details of all the deaths from
cholera in the Golden Square, Berwick St and St Anne's, Soho, districts and
plotted the distribution of deaths in London on a map. He determined that
an unusually high number of deaths were taking place near a water pump
on Broad Street. Snow's findings led him to petition the local authorities to
remove the pump's handle. This was done and the number of cholera
deaths was dramatically reduced…”
• The work of Doctor Snow stands out as one of the most famous and
earliest cases of geography and maps being utilized to understand the
spread of a disease.
http://www.bbc.co.uk/history/historic_figures/snow_john.shtml
http://www.csiss.org/classics/content/8
Epidemiology Groups
• National Cancer Institute (NCI)
http://www.nci.nih.gov/
• Center for Disease Control (CDC)
http://www.cdc.gov/
• World Health Organization (WHO)
http://www.who.int/en/
Epidemiology Software
• HealthMapper (World Health Organization)
• Epi INFO (Center for Disease Control)
• EpiAnalyst (Research Epidemiology
Geographic Software)
HealthMapper
• Developed by the World Health
Organization
• user-friendly data management and
mapping system customized specifically
for public health users
• In use by over 60 countries
• Major diseases that are tracked:
– Malaria, HIV, TB
http://www.who.int/csr/mapping/tools/healthmapper/healthmapper/en/
HealthMapper: Positives
• Cost: Free to Public Health Officials
• Ease of Use: Designed to be used by non
•
•
specialists
Compatible with ESRI software
Preprogrammed with essential health
information
– 3rd world information such as water source location,
health care facilities, and tribal locations
http://www.who.int/csr/mapping/tools/healthmapper/healthmapper/en/
HealthMapper: Negatives
• Free – You tend to get what you pay for
• Future Support: Publicly funded
organization can lose funding for project
• Only has 25% functionality compared to
full GIS software packages
http://www.who.int/csr/mapping/tools/healthmapper/healthmapper/en/
Epi Info
• Created by the Centers for Disease Control
• Designed for users with little experience
with GIS software
• Used for tracking infectious disease and
other diseases like cancer
• Mainly used in USA
http://www.cdc.gov/epiinfo/
Epi Info: Positives
• Cost: Free
• Designed to be easy to use
• Extensible
• Compatible with Access, SQL, VB 6, ESRI
• Easy to obtain
– Can be downloaded off the CDC website
• Widely used in pubic health community
http://www.cdc.gov/epiinfo/
Epi Info: Negatives
• Support: Publicly funded project
– Funds could be pulled at any time
• Functionality: Has roughly 30% of the
capabilities of ArcGIS and other major
systems
http://www.cdc.gov/epiinfo/
EpiAnalyst
• In use by NCI
• Software extension for ArcView GIS
• Used
– to evaluate reported space-time disease clusters to
see if they are statistically significant.
– To test whether a disease is randomly distributed over
space or over time or over space and time.
– To perform geographical surveillance of disease, to
detect areas of significantly high or low rates
http://www.phrl.org/REGS/Info%20EpiAnalyst.htm
EpiAnalyst: Positives
• Support: ESRI is a large company that is
expected to survive well into the future
• Learning Curve: EpiAnalyst is an extension
to ArcGIS and is expected to function
similar to other available extensions
• Compatible with the latest version of
EpiINFO from the CDC.
• Interfaces with major statistical databases
http://www.phrl.org/REGS/Info%20EpiAnalyst.htm
EpiAnalyst: Negatives
• Cost: Increased cost over the alternatives
– EpiAnalyst cost: $698
– Requires a licensed copy of ArcGIS ($ 1,500)
• Not in major use in the public health
community because of cost
http://www.phrl.org/REGS/Order.htm
http://www.esri.com/software/arcgis/arcview/how-to-buy.html
Improvements
• Disease frequency information should be
built into system
– Statistical anomalies should be automatically
tagged
• Improved ease of use for non-GIS
professionals. Example: Epi Info is NOT
easy to use
Epidemiology Groups and GIS
National Cancer Institute (NCI)
• the identification and display of the geographic patterns of cancer
•
•
•
•
incidence and mortality rates in the US and their change over time
the creation of complex databases for the study of cancer
screening, diagnosis and survival at the community level
environmental exposure assessment through satellite imagery
spatial statistical models to estimate cancer incidence, prevalence
and survival for every US state
development of new methods of displaying geospatial data for clear
communication to the public and for examination of complex
multivariate data by researchers.
http://www.nci.nih.gov/
Epidemiology Groups and GIS
Center for Disease Control (CDC)
• Lead federal agency for protecting the health
and safety of people - at home and abroad
• Serves as the national focus for developing and
applying disease prevention and control,
environmental health, and health promotion and
education activities designed to improve the
health of the people of the United States
http://www.cdc.gov
Epidemiology Groups and GIS
World Health Organization (WHO)
• Analysis of disease specific information in relation to
•
•
population settlements, surrounding social and health
services and the natural environment.
Analysis of epidemiological data, revealing trends and
interrelationships that would be more difficult to discover
in tabular format.
Allows policy makers to easily visualize problems in
relation to existing health and social services and the
natural environment and so more effectively target
resources.
http://www.who.int/
QUESTIONS?
(please no!)