Use of geographical information system (GIS) in prevalence studies

A GIS approach provides visualization of spatial patterns in prevalence of diseases.Aim:To determine spatial pattern and association of geographical risk factors on prevalence of COPD among fuel users in a rural setting of India.A total of 3,592 individuals participated in the study conducted in the rural setting of Vadu Health and Demographic Surveillance System(HDSS)in Pune district,India.The participants filled in respiratory health questionnaire and performed pre and post bronchodilator spirometry(ndd Spirometer) according to the ATS/ERS standards.Global Positioning system(Garmin eTrex, USA) was used to record the spatial information and ArcGIS 9.3,USA was used for GIS mapping and analysis.Using GIS tools, two spatial groups were defined;those living less than 500m of the motor highways and those living beyond 500m. Spatial statistics and logistic regression analysis was used to determine the spatial distribution of COPD and its association with geographic risk factors.Results:The COPD subjects residing 500m from the highway show significantly clustered pattern(Moran9s Index=1.7;p