title: Modeling travel impedance to medical care for children with birth defects using Geographic Information Systems.
abstract: BACKGROUND
  Children with birth defects may face significant geographic barriers accessing medical care and specialized services. Using a Geographic Information Systems-based approach, one-way travel time and distance to access medical care for children born with spina bifida was estimated.
  
  
  METHODS
  Using 2007 road information from the Florida Department of Transportation, we built a topological network of Florida roads. Live-born Florida infants with spina bifida during 1998 to 2007 were identified by the Florida Birth Defects Registry and linked to hospital discharge records. Maternal residence at delivery and hospitalization locations were identified during the first year of life.
  
  
  RESULTS
  Of 668 infants with spina bifida, 8.1% (n = 54) could not be linked to inpatient data, resulting in 614 infants. Of those 614 infants, 99.7% (n = 612) of the maternal residential addresses at delivery were successfully geocoded. Infants with spina bifida living in rural areas in Florida experienced travel times almost twice as high compared with those living in urban areas. When aggregated at county levels, one-way network travel times exhibited statistically significant spatial autocorrelation, indicating that families living in some clusters of counties experienced substantially greater travel times compared with families living in other areas of Florida.
  
  
  CONCLUSIONS
  This analysis demonstrates the usefulness of linking birth defects registry and hospital discharge data to examine geographic differences in access to medical care. Geographic Information Systems methods are important in evaluating accessibility and geographic barriers to care and could be used among children with special health care needs, including children with birth defects.
authors.affiliation: Department of Geography and Earth Sciences and Center for Applied GIScience, College of Liberal Arts and Sciences, University of North Carolina at Charlotte, Charlotte, North Carolina.
authors.forename: Eric M
authors.initials: EM
authors.lastname: Delmelle
authors.forename: Cynthia H
authors.initials: CH
authors.lastname: Cassell
authors.forename: Coline
authors.initials: C
authors.lastname: Dony
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Radcliff
authors.forename: Jean Paul
authors.initials: JP
authors.lastname: Tanner
authors.forename: Csaba
authors.initials: C
authors.lastname: Siffel
authors.forename: Russell S
authors.initials: RS
authors.lastname: Kirby
mesh_terms: D000328:Adult; D005431:Florida; D040362:Geographic Information Systems; D062305:Geographic Mapping; D005102:Health Expenditures; D006297:Health Services Accessibility / Q000191:economics / Q000706:statistics & numerical data*; D006760:Hospitalization / Q000191:economics / Q000706:statistics & numerical data*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D012042:Registries; D016135:Spinal Dysraphism / Q000191:economics* / Q000628:therapy; D013997:Time Factors
keywords: GIS; birth defects; geocoding; medical care; network modeling; spina bifida; travel distance; travel time