Spatial modeling of colonic lesions with geographic information systems.

Background: Geographic information system (GIS) software has been used in health care systems to display and analyze spatial pattern of diseases and health services.

Objectives: This study was performed to assess spatial patterns of colon's pathologic lesions based on the pathologic reports and assess whether it is possible to use GIS software in health services.

Patients and methods: Archives of pathology of Namazi and Faghihi hospitals, two main referral centers of south-west of Iran, were obtained and reviewed between January 2009 and September 2011 for biopsy reports of patients who underwent colonoscopy. Abnormal biopsies were categorized into five different subgroups according to the type of pathologic specimens. By GIS, spatial patterns of colon biopsies were plotted in different maps and spatial auto-correlation of colon biopsies was calculated using the Moran's Index.

Results: A total of 4815 biopsies from 2663 different patients were reviewed, 53.8% of which were men. Abnormal biopsies were 2781 of all specimens (57.8%). Neoplastic lesions, inflammatory bowel diseases and polyps were 9.3%, 19.3% and 29.2% of total biopsies, respectively. Pathologic biopsies were more common in the distal colon. Maps of all biopsies and maps of specific pathologies were manifested in GIS.

Conclusions: Our study showed that left-sided lesions are still more common in the Iranian population. On the other hand, surveying the right side of colon is as important as the distal part, which necessitates total colonoscopy.