GIS Software Applications GIS Software Applications in Epidemiologyin Epidemiology

Marcus LiscombeMarcus LiscombeBrent CroftBrent CroftGISC 6383 - GISC 6383 - GIS MANAGEMENT AND IMPLEMENTATIONGIS MANAGEMENT AND IMPLEMENTATION

What is Epidemiology?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 Why is Epidemiology Important?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 History of GIS and EpidemiologyEpidemiology• 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 GroupsEpidemiology 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 SoftwareEpidemiology Software• HealthMapper (World Health HealthMapper (World Health

Organization)Organization)• Epi INFO (Center for Disease Control)Epi INFO (Center for Disease Control)

• EpiAnalyst (EpiAnalyst (Research Epidemiology Geographic Software))

HealthMapperHealthMapper•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: PositivesHealthMapper: 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: NegativesHealthMapper: 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 InfoEpi 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/http://www.cdc.gov/epiinfo/

Epi Info: PositivesEpi 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/http://www.cdc.gov/epiinfo/

Epi Info: NegativesEpi 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/http://www.cdc.gov/epiinfo/

EpiAnalystEpiAnalyst• 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: PositivesEpiAnalyst: 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: NegativesEpiAnalyst: 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.htmhttp://www.esri.com/software/arcgis/arcview/how-to-buy.html

ImprovementsImprovements•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 Epidemiology Groups and GISGISNational 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 Epidemiology Groups and GISGISCenter 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.govhttp://www.cdc.gov

Epidemiology Groups and Epidemiology Groups and GISGISWorld 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?QUESTIONS?

(please no!)(please no!)