GIS Software Applications in Epidemiology Marcus Liscombe Brent Croft GISC 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”

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

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.

Epidemiology Groups National Cancer Institute (NCI) Center for Disease Control (CDC) World Health Organization (WHO)

Epidemiology Software HealthMapper (World Health Organization) HealthMapper (World Health Organization) Epi INFO (Center for Disease Control) Epi INFO (Center for Disease Control) EpiAnalyst ( ) 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

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 – –3 rd world information such as water source location, health care facilities, and tribal locations

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

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

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

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

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

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

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

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.

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

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.

QUESTIONS? (please no!)