title: Spatial Distribution of the Population at Risk of Cholangiocarcinoma in Chum Phaung District, Nakhon Ratchasima Province of Thailand.
abstract: BACKGROUND
  Cholangiocarcinoma (CCA) is a serious health problem in Thailand, particularly in northeastern and northern regions, but epidemiological studies are scarce and the spatial distribution of CCA remains to be determined. A database for the population at risk is required for monitoring, surveillance and organization of home health care. This study aim was to geo-visually display the distribution of CCA in northeast Thailand, using a geographic information system and Google Earth.
  
  
  METHODS
  A cross-sectional survey was carried out in 9 sub-districts and 133 villages in Chum Phuang district, Nakhon Ratchasima province during June and October 2015. Data on demography, and the population at risk for CCA were combined with the points of villages, sub-district boundaries, district boundaries, and points of hospitals in districts, then fed into a geographical information system. After the conversion, all of the data were imported into Google Earth for geo-visualization.
  
  
  RESULTS
  A total of 11,960 from 83,096 population were included in this study. Females and male were 52.5%, and 47.8%, the age group 41-50 years old 33.3%. Individual risk for CCA was identifed and classified by using the Korat CCA verbal screening test as low (92.8%), followed by high risk (6.74%), and no (0.49%), respectively. Gender (X2-test=1143.63, p-value= 0.001), age group (X2-test==211.36, p-value=0.0001), and sub-district (X2-test=1471.858, p-value=0.0001) were significantly associated with CCA risk. Spatial distribution of the population at risk for CCA in Chum Phuang district was viewed with Google Earth. Geo-visual display followed Layer 1: District, Layer 2: Sub-district, Layer 3: Number of low risk in village, Layer 4: Number of high risk in village, and Layer 5: Hospital in Chum Phuang District and their related catchment areas.
  
  
  CONCLUSIONS
  We present the first risk geo-visual display of CCA in this rural community, which is important for spatial targeting of control efforts. Risk appears to be strongly associated with gender, age group, and sub-district. Therefor, spatial distribution is suitable for the use in the further monitoring, surveillance, and home health care for CCA.
authors.affiliation: Parasitic Disease Research Unit, Suranaree University of Technology, Nakhon Ratchasima, Thailand E-mail : soraya.k@sut.ac.th.
authors.forename: Soraya J
authors.initials: SJ
authors.lastname: Kaewpitoon
authors.forename: Ratana
authors.initials: R
authors.lastname: Rujirakul
authors.forename: Ryan A
authors.initials: RA
authors.lastname: Loyd
authors.forename: Likit
authors.initials: L
authors.lastname: Matrakool
authors.forename: Amnat
authors.initials: A
authors.lastname: Sangkudloa
authors.forename: Sarochinee
authors.initials: S
authors.lastname: Kaewthani
authors.forename: Kritsakorn
authors.initials: K
authors.lastname: Khemplila
authors.forename: Thawatchai
authors.initials: T
authors.lastname: Eaksanti
authors.forename: Tanida
authors.initials: T
authors.lastname: Phatisena
authors.forename: Jirawoot
authors.initials: J
authors.lastname: Kujapun
authors.forename: Jun
authors.initials: J
authors.lastname: Norkaew
authors.forename: Apinya
authors.initials: A
authors.lastname: Joosiri
authors.forename: Natthawut
authors.initials: N
authors.lastname: Kaewpitoon
mesh_terms: D000328:Adult; D000368:Aged; D001650:Bile Duct Neoplasms / Q000453:epidemiology*; D001653:Bile Ducts, Intrahepatic / Q000473:pathology*; D018281:Cholangiocarcinoma / Q000453:epidemiology*; D003430:Cross-Sectional Studies; D003710:Demography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D015995:Prevalence; D011379:Prognosis; D012307:Risk Factors; D013785:Thailand / Q000453:epidemiology