ABSTRACT
Various address georeferencing (AG) tools are currently available. But little is known about the quality of each tool. Using data from the EPIPorto cohort we compared the most commonly used AG tools in terms of positional error (PE) and subjects' misclassification according to census tract socioeconomic status (SES), a widely used variable in epidemiologic studies. Participants of the EPIPorto cohort (nâ=â2427) were georeferenced using Geographical Information Systems (GIS) and Google Earth (GE). One hundred were randomly selected and georeferenced using three additional tools: 1) cadastral maps (gold-standard); 2) Global Positioning Systems (GPS) and 3) Google Earth, single and in a batch. Mean PE and the proportion of misclassified individuals were compared. Google Earth showed lower PE than GIS, but 10% of the addresses were imprecisely positioned. Thirty-eight, 27, 16 and 14% of the participants were located in the wrong census tract by GIS, GPS, GE (batch) and GE (single), respectively (p<0.001). Misclassification according to SES was less frequent but still non-negligible -14.4, 8.1, 4.2 and 2% (p<0.001). The quality of georeferencing differed substantially between AG tools. GE seems to be the best tool, but only if prudently used. Epidemiologic studies using spatial data should start including information on the quality and accuracy of their georeferencing tools and spatial datasets.
Subject(s)
Geographic Mapping , Adult , Aged , Databases, Factual , Geographic Information Systems , Humans , Middle Aged , Occupational Health Services , Social Class , Young AdultABSTRACT
La epidemiología espacial se utiliza para describir, cuantificar y explicar las variaciones geográficas de las enfermedades; para evaluar la relación entre la incidencia de enfermedades y posibles factores de riesgo, y para identificar los conglomerados geográficos de las enfermedades. Este artículo revisa los principales aspectos de la epidemiología espacial, empezando con una explicación de la importancia de trazar mapas de los datos de salud, una perspectiva histórica del desarrollo de la disciplina, una descripción de los tipos de datos espaciales, algunos métodos de estadística espacial y la importancia de los Sistemas de Información Geográfica (SIG) en el análisis de datos referenciados espacialmente.Algunas aplicaciones de los SIG en salud bucal se presentan también.
Spatial Epidemiology is used to describe, quantify and explain the geographical variations of diseases, to evaluate the association between the incidence of diseases and potential risk factors and to identify spatial clusters of diseases. This article goes through the main aspects of spatial epidemiology, starting with an explanation of the importance of mapping health data, an historical perspective of the development of the discipline, a description of spatial data types, some methods of spatial statistics, and the importance of Geographical Information Systems (GIS) in the analysis of spatially-referenced data. Some applications ofGIS regarding oral health are presented.
