title: Geographic weighted regression: applicability to epidemiological studies of leprosy.
abstract: BACKGROUND
  Geographic information systems (GIS) enable public health data to be analyzed in terms of geographical variability and the relationship between risk factors and diseases. This study discusses the application of the geographic weighted regression (GWR) model to health data to improve the understanding of spatially varying social and clinical factors that potentially impact leprosy prevalence.
  
  
  METHODS
  This ecological study used data from leprosy case records from 1998-2006, aggregated by neighborhood in the Duque de Caxias municipality in the State of Rio de Janeiro, Brazil. In the GWR model, the associations between the log of the leprosy detection rate and social and clinical factors were analyzed.
  
  
  RESULTS
  Maps of the estimated coefficients by neighborhood confirmed the heterogeneous spatial relationships between the leprosy detection rates and the predictors. The proportion of households with piped water was associated with higher detection rates, mainly in the northeast of the municipality. Indeterminate forms were strongly associated with higher detections rates in the south, where access to health services was more established.
  
  
  CONCLUSIONS
  GWR proved a useful tool for epidemiological analysis of leprosy in a local area, such as Duque de Caxias. Epidemiological analysis using the maps of the GWR model offered the advantage of visualizing the problem in sub-regions and identifying any spatial dependence in the local study area.
authors.affiliation: Departamento de Vigilância em Saúde, Secretaria Municipal de Saúde de Duque de Caxias, Duque de Caxias, Rio de Janeiro, Brazil.
authors.forename: Mônica
authors.initials: M
authors.lastname: Duarte-Cunha
authors.affiliation: Departamento de Endemias Samuel Pessoa, Escola Nacional de Saúde Pública, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Andréa Sobral de
authors.initials: AS
authors.lastname: Almeida
authors.affiliation: Departamento de Epidemiologia, Escola Nacional de Saúde Pública, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Geraldo Marcelo da
authors.initials: GM
authors.lastname: Cunha
authors.affiliation: Departamento de Endemias Samuel Pessoa, Escola Nacional de Saúde Pública, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Reinaldo
authors.initials: R
authors.lastname: Souza-Santos
mesh_terms: D001938:Brazil / Q000453:epidemiology; D016021:Epidemiologic Studies; D040362:Geographic Information Systems; D062306:Geography, Medical; D006801:Humans; D007918:Leprosy / Q000453:epidemiology*; D015995:Prevalence; D012307:Risk Factors